CM_1980_B_02

gf~t{i~i8i4e1lto'ta~~

.$W£ick~et

This paper not to be cited without prior reference to the Council*



INTERNATIONAL COUNCIL FOR THE Q 1980/B: 2

EXPLORATION OF THE SEA Fisli Capture Committee









t ; ;ORT OF THE WORKING GROUP ON RESEARCH AND ENGINEERING

ASPECTS OF FISHING GEAR, VESSELS AND EQUIPMENT ~

(~/d p I









* General Secretary, I.C.E.S.,

Pal:egade 2- 4, DK 1261 Copenhagen K

Denmark

*)

u nci l

This p ape r not to be ci t e d with ou t prio r r eferen ce to the Co







Intern ationa l Counci l for t h e rc.M.1 980/B : 2 ---,

Explor a tion of t he Sea ~sh Captur e Committ ~









-

~EPORT OF THE WORKING GROUP ON RESEARCH AND ENGINEERING

ASPECTS OF FISHIN G GEAR , VESSEL S AND EQUIPMENT

...

t (,/',•

I

./.

•

. ';( I "~· ,, i. ,

\ '· ,'f ,, t.'· ... ·'

/



Conven o r and rappor teur E.J. de Boer

Nether lands Institu te for

Fisher y Invest igatio n s,

IJmuid en - The Nether lands





Meetin g time and place 5 and 6 May, 1980

Reykja vik - Icel a nd





Terms of referen ce C. R es~ 1979/2 :13

(a)The Wo rki ng Group on Resear ch on

Eng i neer i ng Aspect s o f Fishin g Gear,

Vesse l s and Equipm ent , c onvene d by

Mr . E.J . de Boer, to e v alua te tech-

nical aspect s of fishing ge a r,

fishing ves sels a nd fishing method s,

with s pecial referen ce t o energy

c onsump ti on of diffe ren t types of

fishing me t hods and possib le ways

of e nergy s aving 0









Co uncil

This re port ~as not yet been ap pr oved by t he Intern ationa l

the

for the Explor ation of the Sea; i t has theref o re at pre sent

~ta tu s of an intern al docume nt and doe s not

r ep r esen t a n advice

given on behalf o f the Counci l .

of the

The provis o that it shall not b e cite d wi t ho ut t he consen t

Counci l should be strict ly obse rve d.









*)

Genera l Secret ary , I .. C.. E .. S o, Pala;ga d 2- 4 , DK-1261 Copenh agen K,

Denmar k ..

PARTICIPANTS



!?~~~~~~ n - Os ten d

Fis he rie s Re sea rch Sta tio

G. van den Bro uck e



Can ada

an d Oc ean s-

De par tme nt of F is he rie s

R.H . Mc ilw ain e

Va nco uve r



Fra nce

Te chn iqu e des

In sti tut S cie nti fiq ue et

G. Ku rc - Na nte s

P~ches Ma riti me s

Lo rie nt

J. Pra do

11



11

"

11 - Bo ul ogn e sur Me r

J.C . Bra ban t



Fe aro es

essartr~d­

Fis k ir a nn sok nar sto van Deb

B. Thoms en

To rsh av n





H am bur g

In sti tut fur Fan gte ch n ik-

G. Fre yta g 11



K. Lan ge

11

" en

Do rni er GmbH -Fr ie dri chs haf

H. Hi rsc hle c hen

Te chn ica l Un ive rsi ty- Aa

P .. Pf eif er



Fin lan d

- Tu rku

Wa rts ila Tur ku Sh i p ya rds

M. Tor ma



Ice lan d

e-R eyk jav ik

Ma rin e Re sea rch In sti tut

G. Th or. ste ins son k

Ha mp ibj an H.E .-R eyk jav i

G. Gu rna rss on Ice lan d - Re ykj avi k

Fis he rie s As soc iat ion of

A. Agu sts son



Net he rl and s

Fis he ry Inv es-

Ne the rla nd s In sti tut e for

B. van Ma rle n

tig ati on s-I Jm ui den

E.J . de Bo er



~~~~~~ Tec hno log y Re sea rch

In sti tut e of :Fi she rie s 11

A .. En dal 11 11 Tro ndh eim

I. Bj,{6'rkum ,, 11 11 No rdn es__

S. Ols e n 11

"

B, Isa kse n

11

" Tl Tro m sp

A. Bre d.e se n " "

P ol and

Gd yn ia

Sea Fis he rie s Ins titu te-

S. J .. Ric he rt



U.S . A.

am bri dg e , Ma

C.S . Dr ape r Lab ora tor y-C

J.B . So om ala s Ser v ice Glo u -

Na tio nal M ne Fis he rie

ari

A. Bl ott t er, Ma ss ..

ce ste r La bo rat ory -G lou ces





- 1-

~!!~~~~ -~ ~!!~ ~~~

Mar ine La bo rato ry- Ab er dee n

P. Ste war t

D.N . Ma c Len nan "

11

"

R.E . Cra ig

If

" "

C.S . VJa rdle

11 11

"

White Fis h Au th o rity -Hu ll

M. Hat fiel d 11 If 11



D.A . Wil ema n



u.s .s . R.

Departci~nt of Com mer cial Fis her ies ,

E. Pos tnik ov . S.R .-M osco w

Min is t ry of Fis her ies of the U.S

G. Gue nna di



F.A .O.

J. Sch arfe Fis her ies Dep artm ent - Rome





AGENDA



1. Pro gre ss rep orts

l

and vid eo- rec ord ing s and v erb a

2. Pre sen tati on of pap ers , film s

con trib utio ns

in Nor weg ian fish e r ies

2.1 . Est ima ted fue l sav ing pot ent ial

And ers End al

dic fish ing fle et

2.2 . Fue l con sum ptio n of the Ice lan

A. Aug usts son and E. Rag nars son

econ omy

Fis hin g ves sel spe ed and fue l

Torbj~rn Dig erne s and And

ers End al

l con sum ptio n of sma ll

2.4 . Cer tain pro blem s con ce rn ing fue

fish ing traw lers

Joz ef K r ~pa and Mar ian Sza tyb elko

Pre sen tati on of film s on

U. K.)

- Aut oma ted lon g - lini ng (W . F . A.-

on sca le 1:4 (F.R .G. - Net h.)

- Mo delt ests wit h rop e traw ls

arc tic win ter con diti ons

- Ice br e ake r ope rati ng in Ant

(Fin lan d)

in Abe rdee n (5 - 7

2.6 . Rep ort of the exp ert grou p mee ting Pra ctic e for the

e of

Feb rua r y 198 0) on the Dra ft Cod :14 )

Con duc t of Fis hin g Gea r Exp erim ents (C.R es 197 9/2

rdin gs on

Pre sen tati on of vid eo - tape r eco

- The beh avio ur of traw ls in act ion and the rea ctio n

r

of fish to the app r oac hing gea

C. S . War dle

pur se - sein e

- Mo dele xpe rim ents wi t h a tun a

Joe l Prad o

ven tion al and a rop e traw l

2o8 o Eng i nee r ing tria ls wit h a con

of 2700 mes hes circ umf eren ce

Mar len

Dav id No Mac Len nan and Bob v a n

whi ting fish ing e x p e-

2. 9. Pre lim i n ary rep ort of the olu e

Far ce- Isla nds in Jan -

rim e nts eas t/so uth - eas t of the

Mar ch 1980

Bj~rnur Isak sen

Ste in Hja lti i Jak obs tov u and

r ela tion betw een the

2.1 0. Pro blem s enc oun tere d in the c or

anc e tria ls of ful l

res ults o f eng ine erin g perf orm

mod el traw ls tes ted

sca le t r awl s at sea and sca led

e Tan k, Hul l

in the Whi te Fis h Aut hor ity Flum

D.A . Wil ema n -2-

sig n of a

the t ow ing dra g and de

An inv est iga tio n int o

pe lag ic ne t

er

H. Hir s ch le and H. Pf eif

dev elo pm ent

2 12 . Sc al l op dra g tes ts and

n Eo Nu lk

Ala n J o Bl ott and Ve rno

ch ing is daw nin g

2.1 3. A new era f or kr ill cat

Ma tti T. Tor ma

ge ar ins tru me nta tio n

La tes t dev elo pm ent on

Pe ter Ste wa rt

e tra wl s,s ca le 1 : 4

Mo del ex pe ri me nts on rop

Bob van Ma rle n



3. Rec om me nda tio ns

nd a ite m 1 .

Pro gre ss rep ort s - age

the pa rti cip an ts

ss rep or ts is to inf orm

Ob jec tiv e of the pro gre by me mb er cou nt rie s

and pla nne d ac t iv iti es

ab ou t rec en tly sta rte d ent and ve sse l dev elo pm

ent .

in the fie lds of ge ar tec hn olo gy , equ ipm





~~~~~~~ s tes ted e

pe for shr im ptr aw ls wa

A new typ e of bo bb in- gro un dro It is exp ec ted

con nec ted to a cha inG

The bo bb ins are of rub be r and r res i sta nc e

dro pe wi ll hav e a be tte

tha t thi s typ e of bo bb in- gro un

ag ain st ab ras ion .

wls we re fur the red .

pe rim en ts wi th bea mt r a

Co mp ara tiv e fis hin g ex

th two sw eep

ne ts in com bin ati on wi

Th ree typ es of sem i-p ela gic

the co ast al fle et.

sys tem s we re tes ted for

typ e) we re tes ted

ott erb oa rds (po lyv ale nt-

The po ten tia l s of ov al

al fis he rie s.

for ap pli ca tio n in co ast ng ati on /

we re tes ted on the ir elo

Po lya mi d and Po lye thy len e ya rns dr yin g.

rep eat ed mo ist en ing and

shr ink ag e ch ara cte ris tic s aft er eti c ya rn s

abo ut 65% of the sy nth

rep ort ed tha t in Be lgi um is Po lye thy -

It wa s mi d $ The rem ain der 35%

use d in fis he rie s are o f Po lya d by the

ya rn , etc are on ly use

len e. The IoS . O.- sta nd ard s for

t ute .

Fis he rie s Re sea rch In sti

s tes ted .

de r of Du tch de sig n wa

An on -bo ar d fla tfi sh gra

lse -ge ne rat or

ate r, ba tte ry pow ere d pu

The d ev elo pm e nt of an un de rw be pu t int o

d. Th is ge ne rat o r wi ll

for shr im p fis hin g wa s sta rte itc h.

me ans of a pre ssu re sw

the op era tio n mo de by

rgy on bo ard fis hin g

ib ili tie s of sav ing ene

A stu dy int o the po ss

ve sse ls is pl ann ed .



Ca nad a

hin g f o r cod

tto m- set lon g-l ine s fis

In Ne wf oun dla nd a tri al wi th bo ok ing rat e of

e wa s t o com par e the ho

wa s ca rri ed ou t . The ob jec tiv The mo nof ila me nt

gan gio ns _ (sn oo ds) .

spu n ny lon and mo no fila me nt par ed wi th on ly

r hu nd red hoo ks as com

gan gio ns yie lde d 47 o5 fis h pe

gan gio nsG

19 .1 for the spu n ny lon

ct wi th the sea bed

mi dw ate r tra wl in co nta

Tr ial s wi th a rop e-w ing ug h the ne tso un de r

re no t su cc ess ful . Al tho

wh en fis hin g for cod we and eve n tho ug h com me

rci al

ind ic ate d tha t the ne t beh ave d pro pe rly e are a the ca tch of

th bo tto m tra wl s in th

tra wl e rs cau gh t cod wi

tra wl wa s alm ost ni l .

the rop e -w i ng mid wa ter

-3 -

Comparison of ship sounder with netsoun der t r a ces indicate d that

cod was avoid i ng the tra wle

Squid jigging e xperiments were conducted i n t he Ha lifax region by

two 12 metre i nshore vessels~ For comme r i al demonstr a tion the s e

vessels were fitted with automated Japane se equipment~

In the New Brunswick area pair bottom tr awl i ng with inshore v es sels

was demon~trated . The pair trawl was twice as large as the net

towed by single boat operation.

The developmen t and promotion of stern drum seining on the east -

coast continued with the outfitting of a 13 o5 metre vessel.

Both for commercial operation and for demonstration a 13 metre

Norwegian fibreglass sjark class vessel has been fitted with a

full shelterdeck and a complete 11.000 hook Mustad Autoline - system ~

On the west coast a proto-type of a combination mid1t1a ter/bot tom

door was tested .. This door has features of both the German Suberkrub

and the French Portier - door ~ The aspect ratio is 1. 3 and the tow

plates are fully adjustable .

The development of rope trawls was furthered ft Tests were carried

out with pressed aluminium eyes and spliceable ropes of 7/8'' and

9/16" diameter .,

The development of an escape mechanism for lost traps in the black

cod fisheries has started. Practice has shown that the normally

used cotton p&nels last too long.

A project has started to catch rock fish onboard a 25.5 metre

combination seiner/long-li ner with the Mustad Autoline-syste m on

hard bottom ground in the a r ea of the Queen Charlotte Islands ~

The latter system is housed in an aluminium container which in off-

season can be stored onshore .

Experiments with hexagonal meshes in salmon seiner are planned .

Trials and demonstrations with very large mesh trawls are planned~





Finland

Full scale trawling experiments in ice condit i ons were conducted

onboard the Finnish ice - operating trawle r "Jarvsaar" . ~rhis 30 metre

vessel with a propulsive power of 1000 h . p . can, when the ice

coverage is less than 80 percent, operate in 30 cm pack ice .

The operations in solid ice is restricted to 5 cm ice thickness.

Model tests with trawling under the ice in different ice condi-

tions were st a rted . These tests revealed that operation in solid

ice up-to 30 cm thickness is feasible . Dep e nding ice coverage ratio,

in pack ice of up-to 50 cm can be trawled .

M6del and full scale exneriments were carried out with the

"Wartsila Air Bubbling System" (WABS) for clearing the aft area

of the stern of ice blocks when shooting and hauling the gear .

Model tests were conducted to locate the optimum position of the

sonar onboard ice operating fishing vessels.

A proto - type of a year - round operating krill factory trawler was

designed . The onboard processing line~ will deliver peeled krill,

krill meal and krill oil.







-4-

Fra nce

i n trod uce d

t mid w at er tr awl s ar e fu l l y

The ver y l a rg e mes h t wo - boa ~ e the s e g ear s

traw l Pr s up -to 6 00 h .p. u

i n the coa st al f l e et . Sm all

. ucc ess fu l ly ..

s

i n sh a llow

g per mit ting bot tom traw li ng

In 1979 a new typ e of rig gin ped . In thi s r ig gin g fou r

ls was dev elo

wat ers wit h thi s t ype of traw d otte rdo or s

doo rs are use d e In add itio n to the two com mon ly use

the S~berkr~b -t ype are pos itio ned a t

two sma ll mid wat er doo rs o f is tha t it is

the end s of the upp er swe eps . The mai n a dva nta ge

rs whe n cha ngi ng ov er to bot tom traw ling .

not nec ess ary to cha nge doo

g pro blem s

bing is c o ntin~ously cre atin

The shr ink age o f pol yam id web . Spe cia l a tte nti on

fish ing for Nep hro ps

for esp eci ally the fish erm en

is giv en to thi s pro ble m.

te d i n t h e

ead line bot tom traw l is tes

A new typ e fou r pan el hig h-h e p ane ls

and the upp er par t of the sid

Me dite rran ean . The top pan el er p a n el

heso The web bing of the low

is con stru cte d of 800 mm mes of 2 00 mm.

sid e pan els has a mes hsiz e

and the bot tom par t of the

rg) co m-

titu t f~r Fan gte chn ik (Ha mbu

In co- ope rati on wi th the Ins Eng lish

s wer e car rie d out in the

par ativ e fish ing exp erim ent par ison ':. re

.re

FRV "So lea " Ob jec ts o f com

Cha nne l on boa rd the Ger man

o





nch traw l wit h ver y l a rge mes hcs u

a Ger man rop e tra~l and a Fre 1980 in

ts wil l be con tinu ed in Jun e

The se com par ativ e exp eri men

the Ba ltic Sea .

rig g e d

so rtin g pan el for Nep hro ps

The res ult s of tes ts wit h a our agi ng.

l wer e enc

ins ide a n ord ina ry bot t om traw

y p u rs e-

Gul f of Bis cay tra dit ion all

In the sar din e fish ery in the are use d.

gth of 2 00 to 300 met res

sei nes wit h a flo atl i n e len rem ents

se sei nes is 60 met res . Me asu

The the ore tica l dep th o f the of 23 me tres ;

rev eal e d an act ual dep th

und er com mer cial ope rati on e.

ord er of 10 t o 20 me tres /mi nut

the sin kin g spe ed was in the

of lon g-l ine we re tes ted .

A Nor weg ian and a Fre nch typ e

an e x plo ra-

e in Oct obe r/N ove mbe r 1979

A dis tan t-w ate r trH wle r mad tom and mid -

dur ing whi ch b o th bot

tor y kri ll fish ing exp edi tion

wat er traw ls wer e tes ted .

nes wer e

els (1:4 0) of tu n a pur se- sei

The per form anc e o f sca le mod

obs erv ed in a bas i n $

rted ~

1 : 20 mod els of doo rs has sta

The con stru ctio n of sev e ral a mod el of a

whe n in ope rati ng wit h

The se doo r s wil l be tes ted

traw ler .

stru ctio n.

ing (tro llin g) is und er con

A sai lin g ves sel f or tun a fish



~ ~~~~~~ -~~E~~ ~ ~~-~~ - ~~~~~~~ rra~ea n

ls on sca le 1: 4 in the Medite

The tes ts wi t h mod els of traw ls m Res ea r ch

per form anc e of rop e traw

wer e in 1979 d ire cte d to the

sph eri cal ott erb oar ds.

sub jec ts wer e rop e traw ls and

h g i ll

ent s t o cat ch gre y mul l et s wit

I n the Wa dde nsea are a exp erim

car rie d out~

net s (PA mo nof ilar ent ) wer e

wa s

ifie d gea r-fo r cat c hin g sol e

The dev el op me nt o f an ele ctr wil l no w be

dev elop men t act ivi tie s

fin aliz ed. The res ear ch and

h an e l ect rifi ed sys tem .

dir ect ed to c a tch pla ice wit

enc es in

S . T.P . M. (Fr a nce ) the dif fer

In co -op era tion wi th the I . of a rop e

r form anc e Ce o g ~ res ista n c e)

cat chi ng and eng ine erin g pe

wl wer e stu die d.

traw l and ver y larg e mes h tra

-5-

a t c h co J ~it h

nts wer e c a rri ed o u t to c

I n the Ba ltic Se a e xp eri me of t hes e

One of the ma in qb jec tiv es

t wo - boa t mid w a ter t ra wli ng. i ng wh ich a a n

sh the lev el of fu ~ l sav

exp erim en ts wa s to es t a bli

tho d .

be obt a ine d wit h th i s me

fle e t.

rod uce d int o the co as t a l

Gil lne t fis hin g was fur the r int e s s ary .

rap hic con dit ion s was nec

Ada pt a tio n on the loc a l hyd rog

ho ds ns

of low - ene rgy fis hin g met

The (fu rth er) int ro du cti on pla nni ng s t age .

lin ing (co d) are in the

a nch or sei nin g a nd lon g -

f a rm wh ich

n c a rri ed out in an e e l

An a uto ma tio n pro j e ct h a s bee

f a p ow er pla nt .

u ses the coo lin g .wa te r o

s h sel ec ti on

the New - Zea lan d pro jec t me

Dur ing thr ee cru ise s of

out .

exp eri me nts wer e c ar r i e d

ets oun de r)

tem (so nar - ech oso und er- n

The int egr ate d fis hf i n di ng sys

FRV "VJ alte r Her vJig " .

is ins tal led onb oar d t h e

fin ali z e d.

Ant arc tic Ex ped itio n is

The rep ort of the 1978/ 79 cou ld be de t e ct e d

erv ati ons is tha t kr ill

One of the int ere sti ng obs

nde rs .

by st a nd a rd 30- 33 kC sou

the Un ive r -

b i ng wer e c a rri ed out by

W ind tun nel tes ts on s he e t web

rni er Ai rcr aft Com pan y .

si ty of Aac hen and the Do



Ic ela nd

out wit h ro pe

b l ue wh itin g was car rie d

Exp eri me nta l fis hin g on ng of the r ope

bot tom tra wl s. The han dli

tr aw ls and hig h - hea dli ne in som e ca ses

The am oun t of cat ch was

tra wls cre ate d pro b l ems . ech oso und er

e xp e cte d whe n exa min g the

mu ch les s tha n cou ld be itin g sho w ed

s h i ng gro und s the blu e wh

tra ces . At the v a rio us fi

r ns .

d iff ere nt beh avi our p a tte

rds wer e

fer en t typ es of ott erb o a

Pe rfo rm a nce me asu rem ent s of dif of the

doo r- and win g-e nd spr ead

ca rri ed out . Among oth ers , the

ge ar was me asu red G

wls wer e car r ied

wit h fou r - pan el pra wn tra

Se lec tiv ity e x per im ent s was det erm in e d .

r of 40 mm cod end me she s

out . The sel ect ion fa cto the win gs .

a few pra wn s esc ape d in

It was obs erv ed th a t onl y

Due to in -

wa ter tra wl s was tes ted .

The cat chi ng of squ i d by mid y squ ids

bel ly pa rt of the gea r man

c o r rec t me shs i z e i n the y fre que nts the are a

squ id, wh ich onl

me she d in tha t are a . Th e e ba it .

ev ery 5th or 6th ye a r , i s ma inly use d as lon g - lin

ne ne ttin g ,

mat e r ial s, e . g . pur se - sei

Va rio us typ es of fi s h i ng

has bee n tes ted .

wl s i s

itin g by hig h - hea dli ne tra

An exp eri me nt to c at ch blu e wh

i n the pla nni ng sta ge .



The Ne the rla nds

ica l ba rri e r

o p ing an eff ici en t ele ctr

The res e a rch gro up dev e l int a ke a nd/ or

fis h to ent er the coo lin g

whi ch pre ven ts fre s h wa ter ana li z ed the

ust ria l pla nts stu die d and

d i sch arg e sys tem s o f ind ctr ica l f ie lds .

(5 and 8 cm -len gth ) in ele

beh avi our of sm all fis hes all flum e tan k

wer e car rie d out in a sm

The se beh avi our stu die s ion s 95 per cen t of the fis

he s

m con dit

(6m x o . 8m) . Und e r opt imu

a l ba rri er .

d i d not pas s the ele ctr ic





- 6-

ste d on boa rd a

sh gra de r was f u r the r te

The pro tot yp e o f t he fla tfi wh ere the com -

aw ler fi shi ng in u n are a

p ow er f ul com me rcia l bea mtr d iff ere d

the con dit i on o f t h e sea bed

po sit i on o f the cat ch and he i nfl u enc e of

itio n t o res ea r ch int o t

fr om pre vi ous te s ts. In add als o tec h-

rat e of dis car ded fla tfi sh

the gra der on the sur viv al

ear ch was ca rri ed ou t.

. ni cal and erg ono mic al res s of

pos s i bil i t ies and con dit ion

Res ear ch was car rie d out int o the ne ry of

s for the p r opu ls ive ma chi

usi ng hea vy and ble nde d fue l oil

ang es of fis hin g v ess els .

dif fer ent t ype s and pow err

f ish spe cie s by

rel ati on t o cat c h i ng fla t

In 197 9 the ac tiv iti es in dev e lop men t of

ion wer e lim ite d t o the

mea ns of ele ct ric sti mu lat esu l ts ob tai ned

tor and ana lys is of the r

a n ew typ e of p u lse - gen era

in re cen t yea r s .

was co n -

of mu lti - chi n e hu ll for ms

The s t udy int o the app lic ati on t he opt imum

to be use d whe n des ign ing

tin ued . The par am ete r stu dy e ves sel s.

ed wit h dat a of 16 - 27 me tr

(be am) tra wl er was ext end the 16- 40 met res ran ge.

ers ves sel s in

As a res ult thi s stu dy cov

w l from t he

net -op eni ng of a r ope tra

The geo me try of rig gin g and dim ens ion s

tra wl of alm ost ide nti cal

D. D. R. and a lar ge me she d in wh ich a lso

ise of the FRV "Tr ide ns"

\ver e stu die d du ri ng a cru r de e n pa rti c i -

the Ma rine Lab ora to ry , Abe

sta f f and ins tru me nts of nve rte d ins t ru-

als o new dev elo pe d and co

pat ed. Du rin g thi s cru ise tes ted .

me asu rem ent s wer e fur the r

me nts for gea r per for ma nce

bur g mod e l

tit ut f~r Fan gt e chn ik , Ham

In co - op era tio n wi th the Ins i ed out o

) of rop e tra wl s was car r

r ese arc h on mo del s (sc ale 1:4 t ra wl

mo del of a Du tch rou ndf ish

Mo del res ear ch on a 1:1 0 sca le the fl ume

dri dge s was car rie d out in

des ign ed for an are a wit h san the ful l

Ce ntr e, Hu ll . In add it i on

tan k of the Fis her ies Tra ini ng i n sai d are a.

ins t ru me nte d gea r tri als

sca le gea r was tes ted dur ing

and thi s

ir sei nes wer e car rie d out

Ex per ime nts wit h Da nis h pa was fu rth er

low -en exg y fis hin g me tho d

re lat ive ly sel ect i ve and

ind ust ry .

int rod uce d in the fis hin g

te d to

of mu sse l far min g was di rec

Te chn ica l res ear ch in the fie ld the se a -

tra nsp o rt of mu sse ls from

f urt he r imp rov e the hyd rau lic

bed int o the ho l d u

Lab ora t o ry, Ab er-

div ing tea m of the Mar ine

In co- op era tio n wit h the for fis hin g

h-h ead lin e rou ndf ish tra wl

dee n obs erv ati ons of a hig e rec ord ed on

dge s and a bea mtr aw l wer

c od in are a 's wit h san dri of fis h to the app roa chi ng

gea r

cti on s

vid e o - tap e . Als o som e rea

ed .

and in the n e t wer e obs erv



!i~::~~~

ent and rel ate d sub jec ts

Ge ar res ear ch and dev elo pm s hoo k

of inf lue nce , amo ng oth e r

The stu dy int o the par am ete rs ime nts

lin es was fur the red . Ex per

sha pe, on the ef f ic ien cy of lon g- is di rec ted

ich the po int of the hoo k

wit h the wid e - gap hoo k, o~ wh n c rea s e in

od, sho wed a 30 per cen t i

to the att ac h me nt of the sno

k.

cat ch- rat e of lin g and tus

ity was stu die d.

ba it siz e on th e sel ec tiv

The inf lue nce of hoo k - and

d lar ge r

ful ly in op era tio n onb oar

The Mu stad Au to lin e sys tem is the pro to-

Mi ni- lin e sys tem , is in

ve sse ls. A sm all e r ver sio n, the

typ e sta ge .

h squ id j i ggi ng

ere st in squ i d tri als wit

Bec aus e of the gro win g int

ign wer e car rie d out e

ma chi nes of No rwe gia n des





-7-

am oun t of

shi ng the inf lue nce bf th e

In the fie ld of gil lne t fi ity a nd the

etc o n bo th the se l ec tiv

flo ata tio n, hag ing rat io,

c a tch rat e was stu die d.

the so-

o f fis h by lo s t gil lne ts ,

Res ear ch to lim it the c a tch sta ge.

the p l a nni ng

c a lle d 11 gho st-n et s , is in

11



of the

g mat e r ial on the qua lity

The inf lue nce of the ne t tin

.

c a tch is sub jec t of a stu dy

int ro-

pot s and hau lin g sys tem s are

In Nep hro ps fis hin g bai ted

du c e d.

was dir ect ed

the ind u s try the mai n eff ort

In the tra wli ng sec tor of w a y in blu e

lan d, F a r Oer ~n d Nor

int o a joi nt pro jec t of Ice use d of whi ch

je ct a mid wa te~ tra wl wa s

wh itin g fis hin g. In thi s pro rop es .

br a ide d hex ago nal

the fro nt par t con sis ted of

in the

ine Lab ora tor y (Ab erd e en)

In co- ope rat ion wit h the Mar Sea wil l

ng exp e rim ent s in the No rth

sum mer of 198 0 pai r tra wli

be c ar ri e d out .

zed .

t ing tra wl has bee n fin ali

The d eve lop me nt wor k on a shr im p sor ect of

duc ted t o det erm ine th e eff

At the mom ent tes ts are con shr i mpi ng .

-ca tch of fis h dur ing

the s wee p len gth on the by

ord er f or

nal mes hes i s in use or on

The pur se- sei ne wit h he x ago ne pro ved

. Thi s new typ e of pur se- sei

sev era l com me rcia l ves sel s age s are :

ng c ape li n . The mai n adv ant

ver y suc ces sfu l whe n cat chi sin kin g

red uce d by 15o5%; the sam e

th e wei ght of the nyl on is a d) and

a bou t 67% of the wei ght (le

spe ed can be obt ain ed wit h

i s le sso

the hyd rod yna mic res ista nce

o ard pur se-

ed net ha ndl i ng sys tem s onb

Th e dev elo pm ent of mec h a niz

r ve sse lso

sei n es is ext end ed to l a rge

men t and r ela ted sub~ects

Ve sse l res ear ch and dev elo des ign of

ld are d i rec ted t o A the

The a cti vit ies in thi s fie ion s onb oar d and

and wo rkin g con dit

new ves sel s, (B) the saf ety

of fis hin g ope r at ion s .

(C) the ene rgy eff ici enc y

ad. (A) des ign ing of fis hin g ves s els

dli ng sys tem s

dec k mac h i ner y for gea r h an

sys tem s

cat ch han dli ng and sto rag e

sea k i nd li nes s stu die s

ad. (B) sea wo rth ine ss and ent

saf ety and life sav ing equ ipm

tru men t a tio n

wh eel hou se lay - out a nd ins

noi se red uct ion

a cci den t ana lys is

ad. (C) ene rgy eco nom y

res ista nce and pro pul sio n

ma chi ner y sys tem s

was te hea t rec ove ry



Un ited S tat es of Am eric a

are car rie d

av ior stu die s in the U.S .

Ge a r res ear ch and fis h beh .), sta te

Fis her ies ~ervice (N . M. F.S

on by the Na tio nal Ma rine k is

ind ivi du a l s. Muc h of the wor

age nci es, un ive rsi tie s, and eff ici enc y

gea r, sam p lin g gea r, gea r

inv olv ed wit h con ser vat ion som e of the pro jec ts und er-

low ing are

an d tec hno log y tra nsf er . Fol

way in var iou s par ts of the U. S.





- 8-

Massac husetts In s titute of Technol ogy is p l ann i ng comp ar i s on

studie s of the hydr o f oil doo r for this surn merD The door s a re

current ly being commerc i a l ly produce d. Aluminum trawl oors

f or shrimp trawls are being develop ed , and the dev e lopmen t of

a semiaut omatic trawl ~ oor hookup has bee n comple t ed.

S tudies on l ~ rge mesh a nd r ope tra wls are pl a nned in c o n ~u n cti on

with M ssachus etts Maritim e Acad em y ~ In additio n, Eass ac h uset ts

a

Maritim e Ac ad e my is testi n g a modifi ed Bo r i s Goshawk to d e ter mi ne

its perform anc e on h a r d bottom and is working on a tow ed came ru

ve hicle for observi ng tr a wlso

In Vi r ginia, midwat er pair trawls have b ee n introdu ce d for th e

bluefis h, mack erel an d sea trout fisheri es.

A hydr a ulic oyster d radge is being tested by commerc i al f i shermen .

Univers ity o f Florida i nvestig ators h ave used their flu me t ~ nk

for t h e develop ment of shr i mp be am trawls now being used c ont-

~

mer cially a n d are current ly testing 1/10 scale doors o f their d e sign

The Univers ity o f Georgia is dev el oping a 3 wing tongue tr awl

f or t he shrimp fishery . Th is will allow sh r i mpers to us e s ma ller

doors to achie ve the same spread wi th a hi gh er headrop e h e i g ht .

The us e of the tru wl will re duce fuel co ns umption .

Vurious lab ora tor ie s of the Nati onal Ma rine Fisheri es Serv i c e

have ongoing project s wh ich ~ere reporte d o n last year~ The s e

include the sea turtle exc lu der shrimp t ra wl . Test i n g of t h e

experim ental t r awl is c o mpleted ? anrl the data is b e i ng ana l y z ed o

A satelli te tra n s mitter and a radio transm itter were ntta c h 0d to

a loggerh e u d t urtle which was release d in the Gulf o f Mex i co.

Bet ween Oc t ober and Decemb er, t J1 e turtle was l ocated twic e b y

satelli te a nd se veral t imes by airplane -mounte d receive rs .

The porpois e trac ki ng programm e is also continu ing with a sec ond

generat ion system under develop ment, a nd seine-r elate d po r po ise

mortali ty i s still being investi ga ted . Current work co ,ce r n s

correla ting diff ere nt s et co ndition s wi t h variatio ns in t he

mortali ty rate.

A spanish semi-pe lagic trawl is being te sJeJ to determ i~e its

ability to selecti v ity catch shortb ell y rockfis h on h ard b o tt om

off Califor nia.

The NMFS ·Glouc ester Laborat ory has some continu ing pro j ec t s which

were mention ed last ye a r ~ They include a study of existin g s cal l op

drags and the design o f a new one, and an investi ga tion of

beam trawls for the sma l l boat fleet ~ A Dutch beam trawl h a s

recentl y b ee n ordered f o r this p u rpose. In additi o n, we have

-under st udy juvenil e f i sh sampler s and a new groundf ish surv e y

trawl for the assessm e t biologi st s.



~ ~ ~~~~-~~~9~~~

Scotlan d

Se mi-pela g ic trawls

A range of semi-pe lag i c trawls has been develop ed whi ch can be

used to catch both pel ag ic and demersa l spec ie so The main

design feature which c ontribu tes to the duel role of the traw l

is th e smaller mesh si z e in the belly compare d with the top

and side p a nels. Thus the trawls have the large mouth opening

and l6w drag charac teristic s o f pelagic nets, whi le t he be l l y

mesh size is appropr iate for the re te nt io n of whitefish~



-9-

in the lowe r pane l com 9are d

This imp lies a larg er a r e a of twi ne

full s c ale test s have s how n

with t he top a n d si des how ever , and

e b elly to the ot her th r ~e

that t he ra tio o f twin e area in th

valu e ( arou nd 0~55) to

p a nels must be l e ss than a crit ical

com merc i a l f i shin g v ess e ls

avoi d dist orti o n o f the n e t. Sev eral

vers ion of t he t rawl wi th

have been u sing t he 200 and 600 HP

cons ider able success~

Rope t ra~1 l s

co ntin ue d in col l abor a t i on

Exp erim ents wit h rope traw ls h a v e

Fish ery I nve stig ati ons,

with the Neth erla nds Inst itut e fo r

ratory ~ Ab erde en, pa :t i ~i­

I Jmu iden . A team from the Mar ine Labo 111

rrid e ns 11

Dutc h r esea r ch ve sse J

pa t e d in gear t r i al s o n boar d t h e

wer e done o n o pe traw ls a n d

when engi neer ing perf orm ance test s

gic traw l o The a dv anta g e of

for com pari son a conv enti onal pela

same mou t h open ing h a s be en

r ope pan els in r educ ing dra g for the

urem ent of t he te nsi on i n

qua ntif ied by the se test s, a nd meas

ul info rma ti on for the de s 1 gn

i ndiv idua l rope s h a s prov ide d usef

of r ope pane ls ..

De mer sal traw l s

a rang e of t h ree- b ridl e b o ttom

Dev elop ment work has c on tinu ed o n

wit h bot. li gh t an d he a vy

tra wls whic h a re suit ab le for use

carr ied out in th e Whi te Fi s h

gr ound rope s . M del test s h av e been

o

e t e sts have ·. ee n do ne on a

Auth orit y Flum e Tank an d ful l scal

200 HP vers ion of the ne t~

Othe r work

on t h e geo metr y of a pel ~t gic

Fu rthe r mea sure men ts ha ve been ma de

g an i mp oved c ompu ter- ba s e d

traw l whil e it is man oeuv red, usin

a c ou stic ping er s atta c h ed t o

syst em whic h can tr a c k up t o four

i s st il l in p: ogr e s s ~

th e traw l . The a nal y sis ot resu l t s

a n d mes h geo met ry o f tr~wl

The theo ry of str ess dist ribu ti o n

ema t ic a l mod e l s o f th e n e t

ne t s has b e en inv esti gu ted 1 and math

ccou nt o f imp o r tan t fea t ur e s

are unde r deve lopm ent whic h t a ke a

prob l ems have b een expe r i e nc ed

s uch a s selv edge jo i n sm Con verg ence

i nv olve d i n thes e mo de l s,

wit h t h e com plic ated equ at i on sets

and work is contin uing~

g e ar on exp os ed pipe line s ( and

Rese ar ch into the effe ct of tr a wl

t h e oil "ndu s tr y ti This i s a n

vi ce vers a) has b een sp onso r e d b y

a n e Lab o ra tor y s taf f have b een

i nter nati on a l proj ect in wh i ch M ri

s show t hat 16 inch diam e ter

invo l v ed as consult a n ts~ The resu lt

forc ed , c a n sa f ely wi t hsta nd

o r la r ger pipe line s , prop erly rein

ro Sma ller p ip elin e s may be

impa c t s fr om the hea vies t traw l g ea

dama ged if l ef t exposed~



ll~~!~~-~~~~~~~

Whi t e F ish Auth or ity 1ls

elec tr i fied b earn t r a v

omp a.rat i ve f is hing e x peri m e n ts v th

Ji

crui ses were ma de u sing th ~

we re furt here do Fo ur exp er imen t al th e or der of

Ame rican Ocea nhar ves ter e quip men t. In t ot al in

r esu_ ts th e ca t ch r a te s

400- 450 t ows were mad eQ Ana lyzi n g the 10% ab ove

o f the ele ctri fied g e a r turn ed out tb be equa l or

e rate fr eque n c ie s o f 4 and

thos e of stan dard beam traw ls . Puls th e e le ct ro de s

6 o25 p.p os . were us e d and the disc h a rge volt a ge of

m t rawl ing spee d was 2-2~5

r a nged f rom 170 to 220 Vo The opti mu less fuel

k n ots o Duri ng towi ng the e lec t ri f ie d g ea r uses 30- 40%

ed beam tr aw l . Ove r a comp le t e c r uis e

th~n the standard~ ch ~ in rigg

t he fuel savi ng was 1 2%~

-10-

t orn tr cnvl a ropr~ tr c-n.Jl

For use as a dual purp ose on- and off -bot

was desi gn e d for 650 HP vess elso

d l ongl i ne b.J.i ting and

'I'he prot ot ype " Auto ·~lip " fully auto mate

used und e r comm erc i al

h andl ing syste m has at the mom ent been

peri od lin e s hoot i ng was

cond ition s for 13 mon ths. Duri ng this

u s uall y car rie d out at 4. 5 k nots ~ The crew o f the 15 m comm er-

The cost s of the unit is

cial fish ing vess el cons isted of 4 men.

a line vvit~ 10 .. 000 hook s .

estim at ed at£ 20.0 00., - 25o0 00 inclu ding

dfish spec ies, mai nl y

Expe rime n t s ar e carr ied out to catc h roun

nds of N.W .Sco tland o

sa it he, by gil lnet s on untra wlab le grou

A feas i b ility stud y into the pos sibi

litie s of ener gy sav i ng in

f ishin g was sta r ted .

init ial size of me s hes

Tr ials were car r ied out to defi ne the

dete rmi ne t h e shril lkag e

takin g into ac coun t the shrin kage .. To

was meas ured afte r fish ing

se vera l code nds of diff eren t mate rial

on and of f the botto m.

for cour seso ~t an a vera ge

The Flum e Tank has been used for 75%

ining t i me is used for

two cour ses p er mon t h are give n. The rema

onen ts, e.g. floa t s~

t e stin g mode ls of t awls~ nets and comp

For dem onst ratio n of the geo metr y and beha viou r of f i shi . . g g e ars

lopm ent work inclu des at

over 100 mode l s are avai lable $ The deve

g wi ngs, a smal l botto m

the mom ent a bo tto m pair traw l with flyin

e botto m trav.r l f or

travJ l f or catc hing s ole an d c:.1. thre e b ridl

vess els of 300 HPo The la tter traw l h as a vert ical neto p e ning

of 12 metr es ..



u . s . s . R ..

fish ing for cod wer·e c a rr ied

Ex perim ents with b o t to m-se t long line s

Sea~

ou t in the coas tal urea of t he Bare ntz

and re d fish were dete r-

Sele ctiv ity fact ors for hadd ock, co d

mi ned v e n fish i ng \!i th botto m traw

vh ls in t he Bare ntz Sea ..

flou nder was dete rmin ed .

The s urv i val rate o - disc arde d smal l

for s hrim p (Pan d a lu s bore alis )

Se l ec tivi ty expe ri ment s when fish ing

c ati on of larg er mesh es

in the Bn rent z Sea resu lted in the a ppli

i n the code nd.,

bing , rope s, etc) h as

Vari ous type s o f fish ing mate rial (web

been t es t ed ..

all year roun d for

In the Norw e gian Sea r o pe traw ls are used

the catc h is 30-4 0 rr etr i c

ca tchin g bl ue whit ing. At an aver age

tonn es per 2 4 hour s u

tra wl was obse rved by

The beha viou r and geom etry of a midw ater

mean s of un derw ater c a mer a's.







~~hing 1'ech nolo gy Insti tutio l!_s and Serv ices.

e v en the wors t pess imis ts

. his ven ture has t aken much long er t han

plete d sati sfac tory ques -

e x pect ed and we are sti l l lack ing com

S memb er coun tries with

tion nair es fr om some i nsti tutio ns o f-ICE

Pol a nd, the Germ an Dem ocra tic

impo rtant fish erie s such as the USSR ,

Coun ci l Reso lutio n 1977 /3:2

Repu blic 9 Canad'~ As you will reca ll

with FAO by prov idin g

requ este d mem ber coun tries to coop erate

that thos e men tione d

the nece ssar y info rmat ion and I do hope

ible dela y. Othe rwis e they

abov e will comp ly with the leas t poss

we cann ot wait long er than

will just have to be left out beca use

-11-

e

June 1980 late st a As can be seen by now the Direct ory will includ

some 50 i n otituti ons, units or servic es fr om 30 to 35 count ries,

a nd

depend ing on receip t of s till utstan ding r eplies t o re quests

ile

enquir i es. Since t h i s canno t go on f o rever we intend t o co mp

and finaliz e what we can ge t by June 1980 , and have t he first

issue printe d a nd d istribu ted as quickl y as poss ible aftere

sm ,

A revise d and improv ed v e rsion~ based on constr u tive critici

correc ti ons and up -da ting inform ation we ho pe to receiv e will

be prepa r ed therea f t er ~ s appropriate~

Promot i on of Fishin g Techno~o&y S~~vices/Units

ia ,

Consul t anc ies provid ed t o develo ping fis heries i nclude d Alger

the Philip pine s , Kenya , Tanzan ia and Za mb i a e Earlie r in dent i-

ficati on consul tancie s to Sierra Leone and Indone sia are b eing

cal

foll owed up by implem en t a tion consul tancie s to assist the lo

autho riti e s in the ac t ual establi shme n t o f nation al fis hing

ti on

techno logy units a nd relate d planning~ program m i ng an d initia

o f syste ma tic de velopm e nt work @ In Sierra Leo ne i t is hoped to

mobili ze a ctive coope r a tion a nd assista nce for the new na tional

ies

fishing t ec hno logy unit from a substa nti a l smal l scale fisher

dev el opment p r ojec t soo n t o be starte d by Ge rman bilate ral aido

-

A simil a r co ope ration could hopefu lly develo p wit h Norway bila

tera l aid in Tanzan i a ~

rw ay

The consul tant f or Indone sia will be our Conve ne r0 The FAO/No

p roject under the CECAF umbrel la for the e stabl i shment of a

nation al f i shing techno l ogy servic e in Senega l as part of the

ly

Direct ion de 1 °0c ~ anograph ie et des Fi ches Maritim es has final

been starte d by en d 1979 y and is presen tly being suppor te d by a

gy

consul t anc y by C~ N ~ d &lec~ Nuclei o f nation al fishin g techn olo

servic es p ro moted by FAO have been cre ated in Mo r occo and Tune sia ,

al though the TCP projec t for Morocc o did n ot mater ialize.

gs and

Recent exampl es for p r omo tion thro ugh co n t ributio ns t o meetin

papers inc l ude the enl a rged versio n o f The Role of Fishin g Te ch-

in

nology in t he Manage ment and De relopment of Inl and Fisher ies

Afr ic a (i n Englis h and French ), a contri buti on on reque st to the

on

magaz ine Oce anus of the Wo ods Hole Oceano graphi c Ins tit ution

Fishin g Techno logy f o r de vel oping countr ie s which are both on

logy

d i spl ay and a contr i but i on on re qu est cove ring fishin g techno

Technology~

for t he McGr aw -Hill Encyc lopedi a of S cie n c e and

The TCP projec t to Brazil provi d ing separa te crash cburse s for

t he techni c al upgrad i n g o f :fisher ies ext ension offi cers in t-he

ering

fiel ds o f fi shing technology~ fish proces s ing and marine engine

is presen tly be ing i mpl e mented o The inte n t ion is to incre as e the

nation al

compet ence for app lied t e chnolo gy of staff for, inter alia,

fishi ng t e chnolo gy servic e s$

CommuniJ_y Fishe ry Ce n t r e (C:E'C ) Develo pment Conce:p t

t he

In deve lop i ng f is he ries increa sing e mpha s i s is being given to

artis anal sect o r and t o an i nt egrate d approa ch at commun ity level.

·FAO has develo ped a concep t wh ich involv es loc a l or regio nal

rs

fisher i es te chnolo gy and extens ion units ( FTEU) servic i ng cluste

of neighb ouring fishin g commu nities with techn ic al backst opping .

logy

A paper Commu nity F i she r y Centre s and the Transf er of Techno

to Small- S cale Fisher ie s by M ~ Ben Yami, whom many of you know

a t or

as a p r olo fi c f ishing techno lo gist, and who is the main initi

o f this c oncept , is o n displa y~ Since fi s h ing techno logy is a major

compon ent of any fisher y deve lopme n t-the c oordin ation of t h is

conce p ~ wi th nation al fish ing techno logy s ervice s/unit

s is

obvi ously i nd icated Some of you may als o be intere st ed in t hi s

paper with regard to r ele vant bi-lat eral t echnic al assis tence

ventur es ..

- 12 -

Train ing cours es

sp onsore d

The lectur e no t es of the joint French (ACT I M) and FAO

Train i ng Course in Fishin g Techn ology for f rancop hone Afric an

of this

coun t ri es, have been revise d and expand ed and a copy

imp rov ed versio n is on d isplay . Also on displa y is a copy of

cause fo r

the prelim inar y re p ort of the simil ar Norwa y funded

anglop hone cou ntrie s o f the Weste rn Indian Ocean area which

n of

was succe ssfull y i~plemented with active partic ipatio

Stein er Olsen and some o f his staff in Cochi n, India , i n

Frenc h and Nor~

Novem ber/De cembe r 1979 ~ FAO is most grate ful to the

wegi an dona rs for mak ing these course s possib le and for the

imple -

active assis t ance and suppo rt of our colle agues in ' the

ment at i on . It is now intend ed to marry the lectu re notes of these

for sim i la r

two cours es to serve as stand ard backg round mat erial

course s on regi onal or nation al level . We hope that we will be

sh versio ns

able to provid e, in due time, Engli sh, French a nd Spani

of this course mate r ial for gener al use.

on more

Prep aratio ns are unde way for a joint French /FAO c ourse

advan ced marine fishin g techno logy t o be hel d a gain with active

IS TPM - parti cip ation in the ir outpo st in Lorie nt by May

1981 .

Reque st to No r way Ai d f o r one course on fishi ng techn ol ogy eac h for

await ing

Centr al Ame ric an and angl ophon e Afric an count ri es are

donor decis ion.

Desig n have

Two Norwa y funded Tr aini ng Cours es on F i shing Vesse l

been held for Engli sh sp eaking parti ci pant s i n Thaila nd and

these cours es

Spani sh parti ci pants in Ecuad or . Lectu re n otes from

are being compi led as a design manua l for small fishin g boats to

be publis hed in both langu ages .



FAO Fishin g Techn ology Public ation s

and Sonar for

In the series of FAO Fishin g Manua ls, Echo- Sound ing

Fishin g and Tuna Fishin g with Pole a nd Line are wit h the eo-

soon.

publi sher Fishin g News Books Ltd. a nd should c ome ,out

There have been deplo rabl e delays with t he finali zatio n of Prof .

Desig ns

Fridm an's manus crip t on Cal c ula ti ons for Fishin g Gear

which is st i ll with our collea gue John Carro the rs. The same

Boats which

applie s to the manu s cript on Squid Jiggi ng with Small

was found to need mu ch mo re techn ical a nd langu age editin g than

Book.

ha d been expec ted and als o to the Fishe rman' s Pocke t

We hope to finish these manus c ript s lates t by Autumn fo r delive ry

sever al

to the eo - publi sher Fis hing News Books Ltdu The re are

more ti tles in diffe rent stage s of develo pment . ·

"serie s) on

The first titl e of the FAO Bette r F i shing Books ("POP

Pair Trawl ing with S mall Boats to be publis hed by FAO in Engli sh,

hopef ully

Frenc h and Spani sh is s till with the printe rs but will

come out scon e The s eco nd title Gilln etting is ready in manus cript

serie s

. and await s printi ng, als o by FAO . More titles of this

which is mean t to serve exten sion worke r s and se mi- litera te

on on the

fis herme n are under consi derati on pendin g the reacti

fir st "test" -issu e.

t of the

The compl ement of Frenc h litera ture to the Engli sh par

FAO Fishe ries Techn ical Paper No. 184, Biblio graph y for Fishe r -

men's Train ing is o n displ ay. The series numbe r is 195

.

The third and last part conta ining Spani sh lite ratur e is with t he

e d by

p rin ters. You may recal l that this mater ial was co~pil

Prof . A. von Brand t unde r FAO contr act. Your const ructiv e criti -

nal mater ial

cism of this colle ction with sugge stions for add itio

on fishin g techno logy is invite d.



-13-

, .

ica~ Pape r Noo 189,

The Engl ish versi on of the FAO .Fish eries Techn

had Qeen p rep ared

Botto m Traw ls f or Smal l - Scale Fish ing, which

out and is on d i splay .

in F re nch by Nede lec anc Brab ant has come

nm The manu scr ipt

The Span ish vers ion is u nder fina l prepa ratio

r on Mo nitor ing

by Dahm and Lang e of the FAO Tech nical Pape

langu age edit "ng

Traw ls in Actio n stil l requ ires subs tanti al

r t he FAO Fish eries

which is unde r way. Of the publ icati ons unde

peop le 0 in the sub- .

Tec h n ical Pape r serie s prep ared by our bo at

leas t part ly

serie s Fish ing Vess el Desi gn, which a re at

i s being fina lize d and

rel evan t, the title s Smal l Traw lers which

els and Stee l Vess els

the furth er tit les Mult ipurp ose Fish ing Vess

ld be ment ione d .

for Offs ho re Fish ing to come out in 1981 shou

neeri ng Appl icat ions ,

The same appl ies to anothe~ sub- serie s, Engi

Main tenan ce of Engi nes

the first title of which Inst alla ti on and

the prep arati o n of

in Smal l Fish ing Vess els is on disp lay . For

perat ed Haul ing ear fo r

the secon d tent a tive title Mech anica lly-O

ested . This p per

Smal l-Sc ale Fish ing, your assis tanc e is requ

de vi c es such as net

is inten ded to p resen t a good sele ction of

on a rrang eme nts and

and line haul ers and winc hes with insta llati

and boat sein ing,

acce ssori e s for smal l boat traw lirig , bea ch

, pott i ng, etc of a

gilln ettin g, hand - en long linin g, troll ing

enta ti on and instr uc -

desig n suita ble for loc al cons truct ion. Pres

il that loca l artis ans

ti ons will be of a k i nd and tech nica l deta

for prod uctio n.

and work shops can use them as prac tical guide

ction as poss ible of

FAO woul d like to have as comp lete a colle

which are or have been

such simp le mech anica l divic es as poss ible

you who are awar e of

in comm ercia l oper ation and urge s those of

tions , sketc hes· ,

or can lay thei r hand s on rel evan t desc rip

to send these to us

draw ings, phot os, etc of such auxi liari es

be high ly appr eciat e d .

soon est. Your coop erati on in this matt er will

devi ces. Hydr auli cally

At pres ent we need only mech anica l oper ated

subse quen t issu e.

d riven auxi liari es will b e deal t with in a

Hull for the prep a-

Th e cont ract with the Tech nic al Colle ge in

meth ods did not

ratio n of film strip s on fishi ng gear s and

with the Germ an-

mate riali z e e Anot her cont ract has been made

are such film strip s

Israe ly Fund for Rura l Deve lopm ent to prep

with out ligh t

on gilln ettin g and on purse seini ng with and

a ttr actio n.



F iel d Acti vitie s

I am sorry to r e port tha~

Re gard ing those relev ant to this Meet ing,

far in deve lopin g the

no sign ifica nt prog ress could be made so

In view of the

e xplo itati on of me so-p elag ics or lante rn fisho

othe r techn ique s

i mpac t of esca latin g fuel price s on traw ling,

ied and thi s is

t han midw a ter traw ling woul d need to be stud

c ert ainly a chal le nging task .

g and also the incre asing

Agai n with rega r d to the need for fuel savin

me ntion ed, the r (~~iv&l

emph asis on smal l -sca le fishe ries alrea dy

b oats and of s a ilin g-

a nd furth er deve lo pmen t of saili ng fishi ng

more atte nti on

c um- auxi liary engin e conc epts gain more and

done ~n the SIDA

Acti ve deve lopm ent work in this field is being

in the Bay of Beng al

f unde d Deve lopm ent of Sma ll Sc ale Fish eries

also conc erned with

P roj e c t (GCP/ RAS/ 040/S WE). This proj ect is

bette r fishi ng

d evelo ping beach and surf lan ding craf t with

ar an log r af t s o

c apac ity than the trad ition al boat s or catam

ancy prov ided by poly -

One 7.4 simp ly cons truct ed hull with buoy

are being teste d as

s tyren e and anoth e r comp letel y enclo sed hull

ng rig for loca l

r eplac emen t for the log r a ft and bett er saili

e also a doub le hull

b oat trial s were start ed in Sri Lank a wher

be i ng cons idere d

c onfi gura ti on for sim~ le be ach land ing is

- 14-

••

I,

~ .

Fur ther e v aluation of sai l propulsion with a u x ili ary mo tor is

b e i ng carried out · n th e UNDP/FAO Vessel Const ruc ti on a nd Bo ttom

Fis hi ng Demonstrat i on Porject (TO N/77/002 ) in Tonga wit h doub le

and single hull craftc One of the two boats bu ilt during the

Da nish financed regional Training Course in Small Fishi ng

Boa t Construc tio n ( GCP/RAF/133/DEN) late 1979 in Sierra Leone,

a nine meter dory, will be used to work out a suitable arrange ment

f or pole engine propulsion using a small statio nary diesel

motor specific ally equipped with a 2:1 re ducti on gear fo r impro ved

propeller performance.

The Norway financed Development of Extreme Shallow Dra ft Fishing

Vessels Project (GCP/INT/~7 0/NOR) is finally app r oaching the

tes ting stageo A 3 2 ft and 42 ft version of the selected p rot o -

type being built in Ghana are expected to be ready soon for

practical fishing tests in ~igeria to start around August 1980 @

Last year we had t o report unsatisfactory results of tests in

Sri Lanka and India with some prototype units of a no vel low

co st ech o sounder for small scale fisheries in developing

countr ies. The manu facturer has just now indica t ed h is cont i ~ue d

intere st and will prov i de some technically improved uni ts for:

testing by the Deve lopment of Small Scale Fisherie~ in the Bay

of Bengal Project (GCP/RAS/040/SWE)~ probably this a utumn in

Sri Lankao

In the field of fishing gears and methods the sail kite rev it a-

li zed by my colleague M. Ben~Yami, may be ment ioned wi th reg ard

to some initial trials with netsonde monitoring which I coul d

inclu de in test trawling with a high opening bottom trawl wi th

two research vessels o f a joint resource assessment proj ect in

the Bali Strait . The concept worked quite nicely and woul d

deserve further study t o conclusively ass ess its limitati ons

and operational feasib i lity for diffe rent trawl gear unde r

differen t conditions~ Small boat operation of fish~cum-l obster

pots and driftnets for swordfish are to be conducted by the

Fi shery Develo p ment Porject (ALG/77/001) in Algeria. Att emp ts

to re duce gear costs by substituting cheaper synthetics such as

polyethylene for polyamide in gillnetting are going on in seve ral

co untries in SE Asia

Of general interest for developing tropical f i s h er ~ es which ha ve

re sources in small tuna and related species and also of dispers e d

small pelagics is the concept of fish aggregation with anchored

o r drifting rafts which is well developed in the Philipp ines

(p ayao) and Indenesia Crampon), btit not known elsewher e. The

s u ccess of the installation of such rafts of novel design by th e

US NMFS for instance in Hawai and Samoa has p r omo ted inc re ased

in terest. Our Regional Fisheries Coordinator Project (RAS/73/025)

is actively involved in testing and eventually introducing such

fi s h aggregat i ng rafts in the South Pacific a rea wit h sta r t s in

Tuva and probably als o in Tonga. A TCP Project for testing th e

fe asibility of such devices for the pole and line fi she r' of

the Maldives and similar tests envisaged for Sri Lanka w ' l l

p r obably be further expanded to othe r suitable fisheries v

e

W are compiling an information paper on this techni que fo r

dis tr ibution to interested parties .

Coming back finally to the development of lat ent re sources a

p r oject idea has been prepared by our WECAF (West ern Cen tral

Atlantic, INT/77/016) Project to assess co mme rci al fishing

opportunities a n d techniques for oceani c squid. This, as the

develo pment of fish i ng techniques for the latent mesopelagic

f is h r esources, cal l s for expertise, vessel services and





-15-

p ing fish er· · es and w ld~

whi ch are b yon d mo st dev elo

11· tie s

f tab le for a don r , ack a ge

be qu ite app rop r i at e and oui

:., H r d ·or e, res e a _ch ves s el

p~ Je~t _o ·s i ly und

e r sub -c on tra ct inc lud ing a mes opc l:=i gl c s

w· th · ·-e ar of tec hni c al

and sci en tif ic sta ff .. B · t h,

squ :id 9 are qui te a cha ll eng e f o r fi .;hi. ng

an d 2 11 mo re so ocH ano c tio n

ent des erv es much mor e at ten

t .eh l ogy and the ir dev elo pm

..

th n P,as be n ass ign ed so far



IN NORWEG I AN FIS HER IE

TED FUE L SAV ING POT ENT IAL



b : A der s End al



SUMMA Yo t u t ory

sen ted at the for thc om ing S ta

Th 's ape r, whi ch wil l be pre of t h _

/B : 14,starts wit h a rev iew

Me _ti g a s doc ume nt C QM~1 980 met hod s a s yet app lied i n

i npu t of some o: the fis hin g og r a mmes

the reb y exp res sed as the kil

N rw • The ene rgy inp u t is de d

kilo gra mm e of gu tt ed and hea

fte l o il nee ded t o lan d one sav in g

tes sev era l are aQs f or fue l

fi hQ The aut hor nex t ind ica ing pot ent ial s o It~ms dis c uGs

ed

~n ive s est i ma tes o f the fue l sav ed a nd

oth ers , the po ten tia ls of spe

in t e pap er inc lud e? amo ng s ~ imp rov ed r opu l-

hin g method

· o~er re duc tio n 9 cho ice of fis r ec ove ry ,

s i n sys t ems , use of hea vy fue l oil s, was te hea t

ern ati ve ene rgy sou rce s and fi bh foreca ~ ti nge

~n ine de- rat i ng , alt







CO NSU MPT I ON Oli' rrHE IGE I. AND

IC FIS HIN G FLE ET

:nL~L

sso n

: A. Au gus ts son and E . Rag nar



,'"'U f1A.RY: Me e t i ng

at the for thc om ing St atu t ory

The pap er wil l be pre sen ted p a pe r dea l s

mai n sub jec t of thH

as doc u men t C .. M.. 1980/B : .5 . The

dif fer ent typ es of ves se ls u

wit h the fue l con sum ptio n of

are giv en for the tot al fue l

the p e ri od 197 2-'7 8 fig ure s

ets

sum ptio n of t he Ice lan dic fle d the

the tot al ins tal led paw ._ an

'he se fi gur es are rel ate d to ste rn traw l ers

fue l con sum ptio n o :.

w igh t o f the cat ch. Nex t the ng

wli ng is ana lize d for the sev e r a l wo rki

~n age d i n bot tom tra ope rat i on o f

In the sam e way the

• · dit ion s of the se ves sel s . d~

eli n and gil lne tte rs is ana liz

p se - sei ner s fis hin g fo r cap cat ch ra tes

iso n of the fue l- and

The pap er end s wit h a com par i ng~

ng dem ers al spe cie s ( _on g lin

f dif fer ent met hod s for cat chi

ill netti ng ~ tra wli ng )





NOMY

ESS EL SPE ED AND FUEl.. ECO



by: T r bj~rn Dig ern es and And ers End al



'" l1M RY: rep ort "Fa :rt og dr · rsto f f ..

- h is pap r s a sh r ten ed ver sio n of the

and fue l eco nom y i n t h fi shi n g

plco nom i i fi · kefl~ten" (Sp eed ted as d cum n '

pre sen

Lle et) b T rbj~rn Dig e ·:-nes and wil l be

s of the pap er hav e as sub j e c t ma tte ·:

C ~ M & 198 0/B : 15 . Par agr aph the ap pli ati on

pee and pow er, spe ed ~eduction and fue l sav ing 9 be ~ ween

nom ica l spe ed and the b a lan ce

o f f uel sav ing dia gra ms , eco

cos ts 11 o

·he fue l cos ts and the "tim e ee d

re duc ing the fre e run nin g sp

. e mai n rec ult s are th at by n

wil l dec rea se wit h 30- 40% whe

ith 10% the fue l con oum ptio n

tea min g

- 16-

t he Noro/e gian f _eet

A 10% re duc ti on i n free runn ing spee d of

wil l resu lt i n an estim ated fuel savi ng of 6o . oob- 8 0 ~ 000 tons

oil is larg ely depe nded

of f ue l oi l u ~owever, the savi ng i n fuel

ated th a t traw lers

n he type of fish ing meth od .. It is estim

tion by :cedu cing thei r

can save 10-12 % of. the annu al fuel cons ump

ee runn i ng spee d with 10%. This figu re is for long line rs 15-20?,6

n d for purs e se i ne r s 20-2 5%.





UMP'riON O.F SNALL FISH :NG TRA\vLERS

CERTAI N PROBLEMS CONCERNING FUEL CONS

y : Joze f K r~pa and Mar i an Szat ybel ko

'ves se l s ~hich a re the

oli s h fish ery ma i nl y oper ates traw ler type

ost univ ersa l craf t f or wate rs i n the temp erate z6ne , par t icu -

ease in p r ices of fuel

larl y i n the Balt ic rJgion~ The sudd en incr

ted th~ sear ch for

nd lub ru cant s in rec e nt year s has nece ssita

catch o

educ ti on of fuel cons ump tion per unit of

follo wing prob lems :

Inve stiga t i ons are comp lex and inclu de the

the adap ting of t he size of vess els and thei r pr opor t i on to

nd~;

the cond ition s e x istin g in the fish ing grou

sear ch for new form s of flee t oper atio n orga niza tion ;

gear and char ges in

decr ease the resi st ance of towe d fish ing

the towi ng syste m;

coqs umin g.

chan ges in fish ing tech niqu e for less fuel-

r fuel cons ump tion per

In the case of sma ll wet- fish traw lers lowe capa city

un i t of catc h has been obse rved wher e the ratio of ,hold

t o traw ler powe r is h i gher (Tab le 1 ).

the t rawl er dr i ving

Th e mean diur nal catc h yiel d incr ease s with

diur nal catc h yiel d and

powe r . The rela tio nshi p betw een the mean

basi s of oper atio nal

the driv ing powe r has been pres ente d on the

Balt ic (fig ure ).

da t a at tain ed by smal l Poli sh t rawl ers the

line ar d~pendence wher e

As can be seen from the diag ram t h is is a

nd to the simi la1· incr e-

t h e i ncre ment s of the catc h yiel d corr espo

ment s of th e driv ing powe r of the vess elo

that give n t he same unit

Basi ng on t hese da ta i t can be conc lude d

80-4 2 0 kW rang e, the

fuel cons u mp ti on and simi lar driv e i n the

traw ler gene rally has no

incr ease in th e dr ivin g powe r of a smal l

per unit of catch ~

i n f luen c on t he annu al fuel cons ump tion

and the traw lerfs

The rela tion s hip betw een the hold capa city

as resu l t s from com-

driv ing powe r affe cts the fuel cons ump tion,

wi t h 250-- 420 kW and

pari so n of un i t fuel cons ump tion by vess els

80 - 250 kW driv ing powe r (Tab le 1) u

of t he iced fish ; the

The crui se dura tion may be limi ted beca use

tuat ions ..

diur nal catc h yiel d may also show larg e fluc

high er V/N r atio end a

Be c ause of thes e factors~ cutt ers with a

r crui ses t o the fish -

smal ler mean diur nal catc h yiel d make fewe

i ng g r o und~ beca use o r slow er load ingo

o This show s the ~ epen­

Suc h a situ atio n is pres ente d in figu re 2

a full y load ed hold ,

den e on V/N of the numb er of cru ises with

per ton of fish take n

and also the fu el cons umed by thes e cutt ers

numb er of crui ses and

du ri ng one year ~ A corr elat ion betw een the

be dedu ced f rom figu re . 2.

f uel cons ump tion per t on fish land ed m_ay

le to in creaf ;e the hold

Thes e da ta show that :. t woul d be des irab

thei r driv ing powe r.

a pac ity o f t he smal l f i sh trawlers and also ( f or exam ple: for

tion

Alt erna tive ly a diff e rent catc h orga niza be

fis h t rans hipm ent from fish i ng ship dire ctly at sea) coul d

im ple me n te d ..

crui ses futri ng a year

Thes e chan ges coul d decr ease the numb er of

tion per unit catc h.

an d in the cons eque nce cut the fuel cons ump

-17-

·Tab le I.







Fuel cons umu tion of sma ll wet -fi sh traw

lers in the ·Bal tic· ·





-r-- -----------rr---~------..,-----·--

--.-~--:-.;..., ·

-----------;------------,------·----- e kG . .+'uel ·. p er -- .t·£

·· ·

l------------:-------:..-------l--- Ho!? : T,::,,r.:. ber• · .1 Cat" h a· V · r

1 ..

' J'-;~ ...... e 1 -:. owe-r· o"f

' • ..... ft r.o-rc;~-'~I

· f Sha '"'"""~----- ~--:

1

f .... -·~-.... .'"'-: l -

f . -fi Clh •a

1· ~ • . I per .day t . N . 1 kr.- 0

~-.::·

J.-

/ 1 cc:p acl ty . 1 or. trip s/ 1 .

~ it

' of veas el a rn.a:Ln €_:ng:Lne • ~·:)wer /l.~vv

I

~ /ton s/da y/ : ./m3/ kW/ ~ - - _..,

.: ~. /!'J/ : ;mea sure d/ ~ /m;. 1 t vess el I t · .









--~+----=~=:--""~+---:~----+---::-=----t------:----t--:---:----+----=_:~:=----c---1·

I · .1 / 1r' ~ : I .I . /k ~." ' I .I .,_. I . - I .L









~-=--=----t----=:=:-

l .:;,.-1; l

l

3D,~ ...'

.2;04 .·

1.

l

7 :-·,uu 1

I

3 J,O l

I

)o,:; 1

I .

·1 · 0,-3~6 ·

I.

l

. .

1

1

.l

u, aoj .

.-

. .

~

r

.l

I

I

·~ I I . · ...:, .· 1

3,08 l 0,48 4· ( 0,1J" .S l

I ~ "'- I ... r _ " 1

_1.;5 ,0;_;

r-.

• 80,0 I 2b,O l

· l .1 l

~ .::1-~)S l 1':1:; ,40 J

l . · l. I

. ·I . I · i

.1 . t

I I .. I . t

• 1,s2 • .0,11 0 1 . 0,2~0 ·. . ·· •

I

t l

1,7-::..,oc t so,o a

.I ~6 ,4 I - . J "' l .. _,.

·

1 :s-L")~E..::.. · •

J

2s7,. :10

""" . '

.t .

t ~ .-~ l . -·

I l t

-- •

l l l . I

5 ' 8' .br .· 1 r, 2 ., ,. . . l ·Q 2 1 4. . l

J -

f

,...~ ,..; a r· ' 0 I .- L (') I l u ' . :::> I '

i .-. 1 r- 1"'\ f".. l 2 J r. ,

t:: I

t ./ V l :; . ' '..., I I

i

~

V

~-4 f·O i . Lt I V ·__, '.,_; l I

.... -----------

I ::; ' ..._,



I t I I . &

f t . t I

. I

I . l . 1

· ---------~------ --------· -----------

i

---------------- -------..---.-.-----~---

--------------.---------









I

....lo

00

I

r s i n t be Bal · ic

FIGURE 1 - Catch per fishin g day of small we t - f ish t rawle









f lurnber

/\---

\; ·

\

® .



A.""·. ...

~

- "" ~~

. ,,

®

.







·. ·. .



'~ ~r-- )(

. ' . .





. .

· ""'j_¥, ot Juel /ku of lis_:_

!

7

.









q100 020

(

0,300 0/,00



i; th ~ ~alt i c

FI GURE 2 - Fuel consu mptio n o f s m l l we t~ f ish t r awl e r s

a





-1 9-

Presen ta ti on of films

opera t ion of

The W. F .. A.-·fil m on autom ated lonf~:l_ni...£,g_ showe d the

the auto- clip system which in rec ent ye a rs has been devel o ped

sy s tem

by the White Fish Autho r i ty. As the name in dic ates the

is bas ed on a small plasti c clip with which the snood can be

line ~

auto ma t ic ally attach ed to and detach ed from the main

This enable s the ma in line to be stored o n a reel wh ile t h e

e sys t em

snoo ds are stored on racks~ A full descr ipt io n of th

is given in C~M.1979/B: 3.

sho w d the

The f i lm on mode lte s ts with rope trawls on scale 1 :4

obser vation s made by the diving team of the Instit ut f~ r F ang -

by t h e

tec hn i k (Hamb urg) of model s design ed and c onstru ct ed

Net herlan ds Instit ute for Fishe ry Inves tigati ons . I n a ddi t ion

c rui e

t o the obser vation s during this coope rative resear c h

mea su r ement s of t he geome try and resist ance of net and ri ging

4 3 4x8 C cm

were carrie d out Q The rope trawls were de rived of a

midwa ter trawl. Two model s were t ested and o bserve d . One had a

a ccten ary .

mes hed upper square and th e s hape of the headl ine was

The other one ha d also ropes in th e upper panel and the s hape

of the headl ine wa s c omput er design ed o

o f th .

Becau se of the g r o wi . g intere st in th~ explo itatio n

Antar ctic kr il l r e sourc es the Warts ila Shipy ard of Turku (Finla nd)

re nd

carrie d out a fe a s i b i lity and design study on the year-

opera tion of a k ril l factor y trawl er in the Antar ctic"

area in

Thi s means that t he v essel also has to opera te in that

winte r condi tions a n d has to cope with pack and/o r solid ice~

t i cs

There fore the ve sse l mu st hav e perfor mance chara cteris

compa rable with a n icebre ake r.

cial d9sign ed

The film showe d t he perfor mance of an icebre aker s p e

and c onst r ucted f o r t h e Antar ctic. One o f the speci a l f eature s of

y ar d t o

thi s vesse l is th e a i r b u bbling system design ed by the

improv e t h e icebre ak i n g performance~ This system c a n als o b e

g a n d h aul i ng

used for cleari ng t h e stern area of ice when shoo t i n

the ge ar .



Feb r ua r y 1980)

Re po rt of the expe r t g rou p meetin g in Aberd een (5- 7

on the Draft Code of Pract i ce for the Condu ct of Fishi ng Ge ar

Exper iments (C . Res $19 7 9/ 2:1 4 )

acLen n n

The rep or t was prese nted b y the conve nor, Mr~ D.N . M

( M i ne Labor atory, Ab erdee n). In

ar i ntrodu cing the repor t h~ ga v e

to t e

a review of the work car rie d out since 1977 which led

p resen t docum en to

e revis e d

He inform ed the partic ipant s of the meetin g that t h

Data I n dex Forms are d ist r i buted by the ICES Secret ar iat~ The

atory f r t h e

n umber of forms as yet receiv ed by the Marin e Labor

p il ot data exchan ge scheme ~ which will be receiv ed a fter o n e year

ed f o r ms

( C.Re s . 1979/ 4:1), is onl y 7o It was noted that the return

ty experi ments o Membe rs f the

were mainly dealin g with s elect ivi

F ish Captu re Commit tee and the Worki ng Group s o f said Co mm i tte e

were t h e re fore urged to f ill in and return some forms~

the f i nal

I n the discu ssion it was me ntione d that in prepa ring

v ersi on of the Code of Pract ice one can in certa in area's r efer

Worki n g

to Cop erative Resea rch Repor t No., 66 "Re p ort of the

Group on Stand ardiza tion of Scien tific Me t hods for Compa ri n g the

Catch ing Perfo r mance of Fishin g Gear" ..

rec o rds,

Furth e r items dis cus sed were t he markin g of e~g ~ trace

cali bratio n param e te rs , check ing of key pa r a meter s, etco



-2 0 -

It was felt tha t th~ draft Code ~f Pract~ce required further

adapta t ion and editing . Mr . DeN. MacLennan was prepared to

prepare a second draft in time f or the fo r thcoming Statutory

Maating . This draft will include parts of the contributio ns

to the first draft by Prof. DrQ A.L. F ridman and V ~ Pe Karpenko

which were receibed at the beginning of the meetingo

The titles of these contributio ns are "Papers relevant to the

methods of technical tests of fishing gear models" by Prof.Dr .

AeL. Fridman and "A contributio n to the developmen t of methods

of the planning of fast operationa l-technical tests of fishing

gear and the prediction of the essenti al operationa l-technical

characteri stics thereof" by ProfoDr . A.L. Fridman and

V.P. Karpenko.





Presentatio n of video-tape recordings



Dr. Clem S. Wardle (Marine Laboratory , Aberdeen) showed the

participan ts video-reco rdings made by the diving team of several

fishing gears in action. Not only the geometry and the performanc e

of gear companents but also the behaviour of the fish in re l ation

to the approaching gear could clearly be observedo Among others,

the herding effect of bridles and the influence of exhaustion

on the behaviour was demonstrat ed. Next Dr. Wardle informed the

meeting on the application of the remote-con trolled towed

vehicle, recently developed by the Laboratory for underwater

observatio ns.



Mr. Joel Prado (I.S.T.P.M~-Lorient) reported on the recent model

tests with a tuna purse-sein e. Introducing the video-reco rdings he

gave a revie~ of the observation s and measuremen ts in 1977 carried

out during commercial o pe rati on with a tuna purse -seine.

The full scale dimensions of the p urse-seine were 1100 x 150

metres; meshsize 100 mm and 11 0 mm. The model tested in a large

basin (50 x 12.5 m) had a floatline of 29 metre length and a

(stretched) depth of 4.0 metrea The meshsizes used in the model

were 16 mm and 20 mm.

To simulate shooting the basin was equipped with a rotating

platform . In addition a mini-pursew inch was installed. For

observation s of especially the behaviour of the seine when

sinking and during pursing two underwater video-came ra's were

used.

The main objectives of these modeltests were to observe the

behaviour of the gear with different shooting and pursing speed

and the influence of the purse-line length on the performanc e.









-21-

TIONAL AND A ROPE TRAWL OF 2700

MES HES

ENGINEERING TRIALS WITH A CONVEN

(= 20 cm) CIRCUMFERENCE

Mac Lenn an

by : Bob v a n Mar len and Dav id N.





Summ a ry

exp erim ents were do n e on 2'70 0

Dur ing Nov emb er 1979 eng inee ring

ce pela gic traw ls, a size com -

mes hes (equ al to 20 cm) circ umf eren

toda y .

mon ly used on Dutc h ster n traw lers et a nd a

The set of traw ls test ed con sist ed of a con ven tion a l n

.-Fi schk omb inat " at Res tock ..

ro p e tr a Hl desi gne d at the "V. E.B a Dutc h

This t raw l a nd the lice nce to bui lt it was purc hase d by

sidi sed by the Dutc h Gov ernm ent ..

fi r m c c:1.lle d "Jac zon ", par tly sub of the

Like i n prev ious yea rs the test s were done on bon rd

invo lvin g both the Net herl and s

fish ery rese arch ves sel "Tr iden s", Mar ine La -

Ins titu te for Fish ery Inv esti gati ons in IJm uide n and the

bo ra to r y situ ated in Abe rdee n.

same rigg ing i .. e . the same set of

Both ge a rs were test ed with the

brid les (71 fms (=12 9,93 m) for

Sube r krub doo rs (7 m2) and the same

m) for the low er one) and brid le

the upp er one and 70 fms (=12 8.10

3 N) to 1100 kg (107 91 N) .

wei ghts vary ing from 720 kg (706

floa ts on the hea dlin e (230

The rope traw l was also test ed with

eac h).

"No kalo n" floa ts of 2 ltr. volu me 600 m, apa rt

For mos t hau ls the war plen gth was kep t con stan t at

gth var iati on up- to 900 m was

from thre e hau ls whe re a war plen poi nts on the

incl ude d . The warp s were atta che d to two diff ere nt

mos t effi cie nt ang le of atta ck.

doo rs in ord er to dete rmi ne the ir effe ct of tide

Rec ipro cal cou rses were sail ed to take acco unt of the

or cur ren ts.

has been used as dur ing the 1978

Bas icly the same set of inst rum ents

itio n new load cel ls, reco rdin g

tria ls (see refe renc e (1)) . In add -

blin g long er hau ls to be mad e with

on a cas sett e tape were used ena iati on in the leng th

was no var

out hav ing to repl ace them . The re had not

of the brid le exte nsio n. The leng th of the cha in wei ghts

done with the mere obj ecti ve to

been alte red . Sev eral hau ls were rope traw l.

dete rmin e the load dist ribu tion amo ng the rope s of the

s of the top and bott om pan els

It turn ed out , that the cen tre rope the side

were hea vier load ed than the rope s at the side s. For

ion in the rope s nea r the top-

pan els it was foun d, tha t the tens bott om

pan el was slig htly high er than tha t in the rope s nea r the

was also more dep end ent on the

pan el . The load in the top rope s

spee d .

the top and bott om pan els

At a spee d of 4 . 5 kno ts the rope s in thos e in the side pan els

,

a ccou nted for · 56% of the tota l load

took 31% and the selv edg e rope s 13% .

the inst rum ent trac es, cal ibra -

The mea sure men ts were read from

stor ed in the Mar ine Lab orat ory

tion s were app lied and the res ults

gea r tria ls data bank e

per side caus ed the net drag to

The add itio n of 480 kg of wei ght

ven tion al and the rope traw ls.

incr e a se some 5% for both the con

rope traw l incr ease d its drag

The add itio n of 230 floa ts to the

tion al one had nea rly the same

by 13% . Thi s traw l and the con ven

. The pro por tion of the sha ft

drag with 1100 kg brid le wei ghts

seem ed to be very con sist ent for

hors epo wer used to tow the gea r

(on ave rage 28% at 4 kno ts and

all the gea rs at the same spee d

32% at 5) .









-22 -

As could be e x pected, adding bridle we i gh t in t rodu c ed more head-

line height for both trawls; this i mproveme n t wa s g r eater at

higher sp ee ds . The a ddition o f f l oa t s with t he r ope trawl caused

the headline height to increase p r oport i o n ately mo re at low e r

speeds . The side line spread of both nets d i d not var y much .

The cross section areas of the conventional net dec r eased starting

from the wing end going to the cod end as would be expected with

this type of net .

The rope trawl behaved differently in this r e spect, having a

cross section area at the beginning of the netting panels greater

than the headline centre area, a f a ct that could be caused by

slack netting in the bottom panel . The rope tension tests seem to

indicate in this dire cti o n.

From these tests it can also be concluded, that the rope trawl

was slightly overspread. A smaller set of doors could have been

used for this net. The floatation on the headline of the rope trawl

did c&use this gear to fish higher relative to the doors .

A measure to compare the performance of different trawls is the

net drag per unit area .. Compared with the conventional net and

with the same weights this quantity was 26% less at 4 knots and

33% less at 5 knots for the rope trawl without floatation .

The floats on the la tter trawl increased the net drag per unit

area by 10% with 1100 kg bridle weights .. The performance of trawls

can also be judged from the towing speed multiplied by a cross

section area and divided by the net drag , i . e . the "swept volume ·

index" nnd for this parameter it was also found, that the rope

trawl was much superior to the pelagic trawl, irrespective of the

bridle weight used.

The doors showed a consistent performance with much less asymmetry

than that reported in previous years. With the low bridle weights

(720 kg) the doors came near the surface at the higher speeds,

indicating this weight to be too low for both gears with these

Suberkrub doors of 7 m • 2

The attachment point of the warp to the door seemed to be of

small influence on the behaviour of the doors, with the point

cl ose st to the door surface slightly in favour, because of the

less varying door spread as seen on the echo - sounder traces.

The heavier weight lead to smaller heel angles for both doors ..

A warplength increase from 500 m up-to 900 m did not seem to have

a great effect on the horizontal dimensions of the gear .

For North Sea con ditions the length of t he warps paid out will

mostly be determined by the depth o f the seabed o

In addition to tests done in 1978 with a 26 mm diameter warp,

this year trials have been conducted with a thinner warp , namely

of 16 mm diameter.

The pressure drag and skin friction coefficients did not depend

significantly on the diametere There exists a speed dependance

however, probably caused by the vibration of the warp, excited by

vortex shedding and not by differences in the Reynold's Number.

For all warps commonly used in fishery the following empirical

formulae could be derived:

Cd = 2. 078 - Oo298 4 * V

2

Cf = 0. 00625 + 0.02702/V • 465 with V being the speed in m/s ..

These coefficients have been used in the analysis of the data

describ~d in this reporta Conclusively one can state, that rope

trawls can be favoured from an engineering point of view, but

problems may arise with the handling of these nets and the fishing

capability ..





- 23-

Comparative fishing tests will be done in March '1980 on "Tridens"

to complet e this study .



~~~~~~~ -~!-~~ ~e~~~!~~~ -~~~-~~~~~~~~~~!!~~~

A cooperative research programme like this, involving several

institutes (The Netherlands Institute for Fishery Investigations

and the Marine Laboratory) proves to be benificial for both .

The quality and quantity of measurements done is increasing from

year to year, leading to a better reliability and less scatter in

the graphs of the report of the 1979 experiments . The cooperation

also reduces costs of buying or developing instrumentation for

each institute involved . As a by-product some very interesting

experiments like the warp - shape experiments could be done merel y

due to the fact that the trials took place in a very suitable

physical environment having both a great depth and a calm seastate .

It would be wise to continue and extent such cooperative pro -

grammes in the near future · leaving room for each party involved

to fill in their own needso

For both gears 720 kg bridle weights seemed to be too little a

The doors will get at the surface at higher speeds (around 5

knots). The vertical opening of the nets can be improved considerably

by adding more weight (1100 kg), although this will cause the gears

to fish deeper. In order to overcome this, floats can be mounted

on the headline with the penalty of having more drag .

2 .. ..

The 7 m Suberkrub doors on these gears showed a better perfor-

2

mance than found in previous years with the smaller types (4.7 m ).

The best attachment point of the warp turned out to be the one

closest to the door surface giving a very smooth hydrodynamical

performance. At bigger angles of a ttack the doors will probably

show flow separation at the leading edge resulting in an instable

run through the water. With 1100 kg the heel angles of the doors

are smaller reducing the tendency of the door to reach the surface

at high speeds.

The warplength had a minor influence on the geometry of the net

mouth. The length needed will depend mostly on the depth of the seabed

in practical applications~

The highest values of door spread/w .e.-spread/side line spread

will be found at warplengths above 900 m (~ 492 fms), but it does

not seem worthwhile to use these length because of the time loss

during shooting and hauling.

From the rope tension tests it was found, that the ropes were not

equally loaded. The centre ropes of the top and bottom panels were

heavier loaded, indicating the gear to be overspread . For the

side panels it was found, that the ropes in the top parts were

heavier loaded. These loads were more dependent on speed than

those of the lower ropes.

At 4.5 knots the total load was distributed as follows:

top and bottom panel 56%

side panels 31%

selvedges 13%

From an engineering point of view the rope trawls seemed to have

a superior performance. This is hopeful keeping in mind the main

objectives of this research programme i . e . to develop a trawl

gear with less drag than that of the conventional types and with

the possibility to fish close to or on the seabed without suffering

net damage. The first mentioned criterion is related to the fuel

consumption of the fishing vessel , This will have an important

bearing on the economy of fishing operations .



- 24-

The second criterion applies to costs of material and repair also

related to the overall economy of fie.hing ..

Both costs aspects need to be cut down in order to survive a s a

fishing industry.

On the other hand one needs to catch fish to earn money and the

fishing efficiency of the gear should be comparable to commonly

used types. Only by comparative fishing tests an insight into a

gear's fishing capability can be found. That is why such tests

are planned with these rope trawls during March 1980 on FRV "Tri d ens" .

A delicate balancing of the costs-saving aspects and the fishing

efficiency (including size and species selectivity) of these new

gears is needed to determine whether this development will be

feasible.

In addition t6 the warp shape tests done in 1978 with a 26 mm

warp, experiments were done with a 16 mm warp this year.

A suitable set of formulae could be derived for the prediction of

skin friction and pressur~ drag coefficients for trawl warps

commonly used in fishery, namely:



cd = 2.078 - o.2984 * v with V in m/s

2 465

cf = o.oo625 + o.02702/v •

Fishing tests with smaller (1736 meshes) rope trawls in 1979

casted doubt on the herding effect of ropes at least when fishing

close to the bottom. Direct observations from divers on rope

trawls lead to the conclusion that the foreward movement of almost

parallel ropes can hardly be spotted. Small fishes did not seem to

react to the ropes at all. It could be worthwhile to develop a

gear with the advantages of the rope trawls such as drag reduction

and less damage when having bottom contact and some means to have

a better herding effect of the rope punel like nrranging the

ropes in a lattice with transverse connections.



References

(1) van Marlen, B & MacLennan, D.N., 1979

Rope trawl developments-further experiments

Report No. 79-03, RIVO-IJmuiden



(2) MacLennan, D.N., 1979

Hydrodynamic Characteristics of trawl warps

Scot.Fish.Res.Rep. No. 16, 1979



(3) MacLennan) D.N., 1980

Further hydrodynamic force me a surements on trawl warps

Marine Laboratory Working Paper 80/5, Mnrch 1980









-25-

PLANNING OF EXPERIMENTS



~~~!---~!~----~!!6~!~--!~~!--~-~~~E!!~~~~~-~!E!:~~~~!-------~~~~~-------~~~~~! -.

01 A 720 4.47 320 0950-1 600 II/b 1.25 °

02 720 4 . 47 600 0905- 1570 . II/b 205°

A 0



03 A 720 4.47 600 0870 - 1550 II/b 25

04 A 1100 4 . 47 600 0875- 1780 II/b 205°

05 A 1100 4 . 47 600- 900 0900- 1700 II/b 25°

06 A 1100 4. 47 600 0937- 1832 II/a 205°

-~ r 0



07 A 1100 4.47 600 1000- 1790 II/a c:.:;;



=================== == ==========

========~========================================

oB B 1100 4.47 600 0965 -1 760 II/a 240°

B 1100 4.47 600 0970 - 1650 II/a 60°

09

10 B 1100 4.47 600 1000- 1700 II/b 260°

1100 4.47 600 0973- 1740 II/b 40°

11 B

======================================

=================================~=~==T===

12 A 1100 4 . 47 600 1276- 1810 II/a 255°

13 A 1100 4.47 600 1300-1 840 II/a 255°

14 A 1100 4.47 600 1300- 1838 II/a 255°

15 A 1100 4.47 600 1385 - 1843 II/a 250 °

16 A 1100 4.47 600 1344- 1825 I I/ a 250°

================~=========~===~

===~===~=~========================~=====~=~======

Warp shape exp.

c 720 9 . 82 600 0960- 1700 II/a 260°

17 80°

18 c 720 9.82 6oo 0910- 1560 II/a

c 720 2-82 200-200 1260 II/a 250°

19

20 c 1100 9.82 600 1135- 1770 II/a 265 °

21 c 1100 9;.82 600-900 1197- 1830 II/a 70 °

22 c 1100 9.82 600 1190- 1825 I I/a 250 °

c 720 9.82 600 0970- 1625 II/a 70°

23









TABLE I









-26-

ROPE THAVJL (A) ROPE TRAWL (B) PELAGIC TRAWL (C)

.Bridle ·.Jeibhts (kg) 720 1100 1100 720 1100

.Speed (knots) 11.• 0 5 .. 0 lt., 0 5.0 4.0 5 .. 0 4.0 5.0 4 .. 0 5~0



1: inc;-crid height (m) 28.0 21 .. 5 32 1

+ 26.9 35-1 27 .7 25.3 21.5

I







0

30.3 24.7

wing- end spread (m) 64.0 63.9 63.2 66e4 62.9

59-9 53 -9 52 . 6 54 . 7 55.6

win8-e nd area (sq.m) 1795 1.375 2011-0 1792 2096 1755 1362 1135 1659 1372

he~dline height (m) 29.7 19.5 32.8 25 .. 3 39.2 28.3 23.5 19.6 28.7 22 .5

clideline spread (m) 49.7 51.6 50.0 53.,0 48e4 51 .. 6 47.2 45 .. 3 48o2 49., 4

h/1 centr e area (sq.m) 111-72 1019 1631 1356 1886 14-80 1111 889 1383 1110

section height (m) 3'1.0 22.1 34.6 27 .. 1 39 .. 6 30.0 11 .. 9 1 L1-. 2

9.9 12 .. 8

s£ction spread (m) 50.4 50.8 48.6 52-3 l L1-6. 6 so . 6 . 6 .. 2

2 25 .. 4 26.8 28~2

~ection area (sq.m) 1557 1139 1671 1432 I 1839 1537 311 253 380 361

hcudline depth (m) 1111.6 '13. () '187. 9 71+.. 5 150 .8 58.8 '121 • 9 29.6 167.) 60o4

door height above

1L1- .. 0 1 -z -1

19.0 16 .. 1 5.8 7-3 15.5 10.? 16.1

the heudline (m) ' ../ • I

13.0







TABLE XIX









CONP ARISCN OF THE THREE TRA\~LS - GEAR GEOHETRY

I

f\)

.....:J

-I

TABLE XX

HOPE TRAWL (A) ROPE TRAWL (B) PELAGIC TRAWL (C)

Bridle h·ci_shts (kR:) 720 1100 1100 720 1100

SJJeed C~nots) 4.0 5.0 4.0 5.0 4.0 5.0 4.0 5.0 4.G 5.0

Net drc::t;; (tonnes) 9-73 13.89 10.16 13.9 11- 11.44 15.70 10o97 13 .. 25 11.42 16 . 10

GeRr dr.:tg (tonnes) 11 .. 59 1'l.91 12.55 16.91 12.89 17-59 12.96 16.03 12.57 I

17.73

Sh&ft H.P. 1132 1659 1236 1764 1278 1827 1246 16L1-1 1271 1896

Gear H .. P .. 319 523 348 562 355 581 356 529 341 586

Swept volume index

(CV .. !-1/SEC/TONNE) 320 173 338 245 346 233 211 165 251 174

Net drag/area

(KGF/SQ.H) 5.60 9 .. 47 5.08 7-72 5.56 8.69 8.24 11.93 6.89 11.47

l

TABLE XX

COHPARISON OF THE THREE TRA\vLS - FORCES AND GENERAL PERFOR!1ANCE

=============;=================================================



TA.BLE:: XXI

ROPE TRAWL (A) ROPE TRAWL (B) PELAGIC TRAWL (C)

3 r i d le v: e i g h t s ( kg ) 720 1100 1100 720 1100

3-c,eed (knots) 4.0 5.0 4.0 5.0 4 .. 0 5.0 4.0 5.0 4.0 5o0

Door HEEL 24.6 40.·4 17 .. 4 33 .. 9 15 .. 6 29o4 30.3 39-3 20.9 34 .. 3

angles TILT 14 .. 3 20.1 10.5 14.9 11 .. 7 14 .. 9 17 . 3 1 2

.8. 13 . 0 14. 2

(De g) ATTACK 32.4 23 .9 21.8

I

35-5 23.3 25 .4 29 . 5 26.6 33 . 0 30.8

Door denth (m) 127 .. 6 -0 .. 1(!) 168 .. 9 58 .. 3 145.0 51 .5 106.4 18 .. 9 151.2 47.4

Door spread (m) 143 .. 1 140.9 139.9 147.7 134.3 142.2 126.6 120.3 129.1 132o4

Door spread force (t) 1.40 1.85 1.47 2.03 1 .. 53 2.13 1. 39 '"I .. 61 1 44

0 2 .. 05

I

1\)

~Jar p at t • p o in t b a + b a + b a a

CX>

I

Combined data for .Speed (knots) 4 .. 0 5.0

All trawls Door drag (tonnes) 0.77 TABLE XXI

1 .. 00

. . ..



COMPARISON OF DOOR CI!ARACTERISTICS-SAME DOORS USED

WITH DIFFERENT NETS AND BRIDLE WEIGHTS.

COMBINED DATA FOR BOTH WARP ATTACHMENT POINTS.

TABLE XXII



COHPARISON OF DOOR CHARACTERISTICS FOH DIFFERENT \·JARP ATTACH!:ENT POIHTS

= ===================~===: ========~=

===~================================







BRIDLE WEIGHTS: - 1100 kg



Warp ROPE TRAWL (A) ROPE TRA\vL (B)

att.

point



Speed (knots ) 4.0 5·::.. 0 4.0 5 .. 0

.

·;.-. :





a 15.6 32.7 15.7 31 v4

Door HEEL b 19.1 36.4 15.-2 25.5

Angles

a 10 .. 3 13.8 10.3 13.6

(DEG) TILT b 11.0 16.8 13.2 16.6



a 21.7 23.4 £;1.8 25.4

ATTACK b 25.9 24.0 - -

Door spread (m) a __139.1 148.8 133.5 140.9

b 140.2 146.1 135-3 143.6









TABLE XXII

! . .. •-=.-

IN

MR2EN

}.l l tli>T£

( t1M)

BDVENKRNT _CUPPER SIDE) , Dln£ L;

6E51R£X •

1 ~ j







I ouo OD





FIG~









IS: !BZ3 IN HH 18

211Y a 71.~3

ut= e.a.m Li.B

DPP.= B. Bfili



Lf IBBa

UJ= a.a.m

IN HH HT 2l~M

li .B . I V









DPP.= B.37Lf 2 Bfi

l









UI= ~L 'YI!J

DPP.= 7.B~Y M2 IN '18 f.i] .!M!









. ·-·- -··- -----·--·---- - ~--~

25: BB~

Ul= B.lfi!J

DPP.= 2. JBJa .M2 IN 3B



~

UJ.c:: 2.Lf~ 11~

?S: Y~H 219/ ~

1.23~

IN 38 HLBB

DPP"= H2 BB 2Ji

UJ= Pl.'ii?I lEa :tlfU s

~a 22B IN 2B

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J 10 l:.9

l------4 225:

r~a IBB Ul= B.'-m 2 11U I!

DPP.= I. 7~PJ H2 iN 213 IB.B1l

12~ l!.ii

26B [2.75]



ygpj '"~~

Ul= B."W 1HY 1fl lB . ~

DP?.a 3.293 M2 '2.3







UI= l.:L LfB 2HY &1

DPP.=

iN BB JB.&?JB

l . 03S: M2 2.3



U1c FL l.fl:d

~--~4-~----l DPP.~:

1 22

H~ B.:3J I



BENRMING= 2700 MRZEN NET -

- -



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-32- SCHRRL

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- 48 -

FR~LIMINARY REPORT OF THE BLUE WHITING FISHING EXPERIMENTS EA3T/

SOUTH-EAST OF THE FAROE ISLANDS IN ~ANUARY/MARCH 1980

by Stein Hjalti i Jakobstovu and Bj~rn~r Isaksen



Introduction

On t h e way to t he spawn ing ~rea, the blue whiting con gregat~ e2st

nurt h -eust of the Furoes forming prespuwning concentrations, which

l a ter st2r t their migration in the so uthw ards direction over the

Wyvi lle Thomps on Ridge (S ch~ ne 1979)Q The blue whi ting is recordud

a s a more o r less continously narrow l aye r in this areao A~ daytim e

blue whi t ing is fou nd at 1 90-220 ftm depth over re l atively deep wate r

( 2?0-650 ftm)IP

Faroes fishing exper iments in Febr u ary/Morch 1978 and 1979 in the

urea between Fugl~yarban k and the south-east edge of the Farce

Pl2teau gave catches up -to 25 t/h, but in general the catche s were

much low er, and too low fo r successfull industrial fishi ng

(J akobss on 1978, J~kobstovu 1979).



Materia l s a nd methods

Fis hin g exp eriments were conduc ted by the Fa roe M ari ne Research

I :1 s t .i tu t e \'J i t h t vi o c ha r t e re d v e E~ se l. s , m.. s .. ' ' .S i gm u n d u r B res t i s son 11

\·J ith 2800 hp a nd m.. s .. " Krunbor g ' 1 '>·;i th 2?00 hp .. The se vessels 1.-·: ere

be tt er po0ered than t hose th at had been u sed ear l ier for this

kind o f fishi n g exper iments. Both bo ~ ts are rel utively new and

bu ilt as c omb ined trawlers/pur se se ine rs.

" Sigmundur Brestisson" us ed the Fu.r·oes ·16 m t:ravJl (.J.:J.kobstovu

Iv:os ..

19'? 9), ~-Jh i le m., s.. 11 Krunbo rg 11 used the Non.vegi Etrl H- tra vJ l ( Tsaksen,

Jensen und Olsen 1979 ) . Thi s trawl was gi ven on lo a n f rom the

I n ~t~tute o f Fishery Technology Research, Bergen, in a ccord nncs

~ith an i nternordic project an c&tch a n d pro~essing technolo gy of

blue ';ihj ·t.inc. 'Th ree sci enti 3ts of ~.h is i ns titute pll,y .so~lthvJard.

accord.L:Jg to the rnig r s.tion of the blue v:hi ting .. After the ch.::u~­

te r ed period 1 one of t he sh i p~ continued fishing about ~ fortnig ht

on her own ~ ccount.

In th e ~e cond half of January catches fro m 5 to 26 t/h 0er2

bJ l,o;:e r~ ;_:;ou th of Fugl,Jynrbunk, vJi. th o. IT!eo.n of ·'12.,2 t/h (T.:..J.bel ·1) ..

The go o d fi~hing cont inued in February with ca t ches rates from 2

t :J .3 ~ t / ' ~; ~-.f i t h :.:;_ me Ll.n o f ·1'5...S· t / .L .. In Vi t.o V/ o f the h i g h Cl u a l i t y o f

.

t h e f~9Gpnw n i ng blue ~ biting these ca tch r ates are con si~ered very

goo ,) fc.>r ;:.1. fis h ery for hum un c onsumption, and for industrial

fi shi~G th e catch ra tes are Jlso q~ite pro mi singo I n a commerci~l

.fi.:~hPr.;_r ,. ; i th seve r al bo['~ts p c-~rtici.pa. ting the se .:1rching pov;er vvi ll

incre i3e con~ide r ably, ~ n d th e catch rates will most probably



Both m.s. 11 3 i gr;w. ndur Br es ti ss on " and m~s .. 11Krunborg" st ored part

of their C£\ tches on i c e for fileting , the rest vJas deliv ered for

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Headline 87 ft 6 in

APPENDIX 6

WHITE FISH AUTHORITY FLUME TANK DI MEN SION S OF WOR KING SECTION



Towing

Safety

Frame

1

Curtain

Total length of

\ll working section W

1



~--------------- 17 - 42m ---

-----------~







Depth

of Towing Frame

Water for warps

2-5m



No windows! Observation Window s (11) No window s

I 1m wide x 1-5 m high



I

~2-7m - >k 11 -06 m / 3-66m~l

Available Rotating Conveyor Belt 11 .06 m tong by Available for

for towing

-I I 2 Towing Frames can be

4 -8 m wide. All parts of the gear in netting no_t in 1 moved across the tank.

warp s contact with the sea bed must lie in this I contact w1th

etc. Minimum di stance apart =0-97m

area. sea bed_

I 1 Maximum distance apart == 4 -42 m









Width Towing bracket can be set

of

/ t o any height in the tank

I

00 Tank

[\)

!

5m

Towing

~

Ref erence s





1. Nedel ec, C, and Th~orie et Pratiq ue des }1aqu ettes

Portier~ M (1973) "'

d 9 Engin s de Pecheo IS TPM No. 227

Juille t - A~ut 1973



2. Dickso n lV. ( 19 59) Model Nets f'or Exper iment al 'vork.

In Moder n Fishin g Gear of the World :1o





J. Dickso n W. ( 1961 ) Trawl Perfor mance

A study relati ng Model s to Comm ercial

Trawl s D.A .. F.S .. }!arin e Resea rch No. 1.









-83 -

N OF A PELAGIC NET

AN INVESTIGATION INTO THE TOWING DRAG AND DESIG

by: H. Hirs chle and H. Pfei fer









1. INTRODUC TION

try i n recen t years and

The rapid devel opme nt of the trawl fis hing indus

cted in t he desig n

the conti nuou sly chang ing cond ition s has to be refle

of pe lag ic nets.

there were no suffi -

Until a few years ago i n inter natio nal fishe ry,

dures which could

cie ntl y preci se desig n metho ds or calcu latio n proce

ibuti on of t he meqh~

enab le theo ry to deriv e the net's drag, the distr

nt of the ten sion

or its mech anica l prop ert iesp such as the devel opme

in the net and stres s poin ts.

on the accu rate

The cal cul ation metho ds for pelag ic nets are based

ficie nts of the net

knowled ge of t he hydro dynam ic drag and lift coef

f abric .

mainl y withi n the

The ang l es - of-at tack for curre nt pelag ic nets are

of inter est

small range 0 20° howe ver, the tre nd is reversed

and normal force coefficie nt can be observed decreas in g while the me s h

angle i ncre ases. The maximum no r mal fo r ce coe ffic ient i s achieved for

an angle of attack of abou t 50°.



I nfluence of the C'Ol'~d Ifia'Tietel'~/Mesh f-.l idth Ratio



Fi g.2~ 1 displays the normal f orce and ax i al forc e coef f i c ien ts as f unc-

t io ns of the a ngle of attack for t he d/a~ 0 .03, 0 . 06 and 0 . 12 , The mash

an gle had a val ue of 15°. I n pr i nci p le it ca n be seen t ha t tha influen ce

of t ne d/a r3tio on the force coeffici en ts c. , and C~ is low f or ~ very 8~all

" +' k X 2 0[! tl1e a },; l. c l .c c8

· : ..

angles of attack a.. I n t . ang 1 e-o,-a L.. t.ac rang B >

ne ,·or

a nd normal for ce c8 efficient s r i se wit h the d/a ratio increas i ng .



Inf luence of the SuY•1•oundi ng Ne t



To te st t he quali ty of the m sas u reme~ ts ~he influencs of t hs anv i ronmsntal

ne t was investiga te d.



Th e measureme nts o~ the Rod l attice models wit h and wi tho ut h environ-

m en~al ne t pro ve d a great infl uence on the axi a l fo~ c e co ef ficie

nt C •

>-.

abc ve all for small angles of attack.



The ax ial forc e i ncre ase without the e nviron ment al net amo unted up to

50 %' S88 fig. 2 . 12.



Wit h re gard to the no r ma l f orce co ef fici ent C ~ t he de\;la ~ lons are, for

th e most partJ within the ra ng e of t hs accura~y of the r e prudLice a b ili ty

meas ure me nt s . The environme ntal net cou l d be red uced to 4 bars (i n f lo~~

dire c tio n] wi tho ut a me as urabl e mod i f ica tio n of th e f or c e coeff i cients,

588 fig. 2. 12 .





Thi s de mons tra tes th at th e selected test arran gement accu r atsly re pre se nts

the f l ow force s, actua l ly occur on t he net at all a ngl e s -of -at ta c k an d

tha t i t e i i min a tes the effec ts of the finite model . boundary vor t i ces,

aspect r atio, and l e ngth.

Infl.u ence of the ReynoUi.s Number

and norma l force

The influe nce of the Reyno lds number on the axial force

the cord

coeff icien ts in relati on to 4 diame ter is very lowp in the rang e

repro~ .

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REFERE NCES







[ 2. 1] Scharping, K.D.

Beitrag zur Ermittlung des MaBstabseffektes bei der

Modellierung pelagischer Schleppnetze

Oissertationsarbeit an der Sektion Schiffstechnik der

WPU Rostock, 1973



[2.2] Stengel, H. und Fischer, H.-J.

Ergebnisse von stromungstechnischen Untersuchungen

an Netztuchern im Windkanal

Schiffbautechnik 14 (1964)

H. 7, S. 374-381



[2.3] Stengel, H. und Fischer A.

Ergebnisse von stromungstechnischen Untersuchungen

an geknoteten Netztuchern aus gedrehten Poly~midfaden.

Fischereiforschung 6 (1968)

H 3, S. 49 - 59



Koritzky, H.H.

Widerstand und Auftrieb ebener weitmaschiger Netze

Fischereiforschung, 12 (1974) 2 S. 51 ff.



[2.5] Koritzky, H.H.

Neue Methoden und Ergebnisse zu m Bestimmen von Stromungs-

kraften an ebenen rechteckformigen Netzteilen und Netz-

faden

Fischereiforschung 15 (1977) 2) 43 ff.



[2.6] Kruse, W.

Beitrag zur Ermittlung von Widerstand und Auftrieb

ebener NetztUcher im kleinen Anstellwinkelbereich

Fischereiforschung, 15 (1977) 2, 31 ff.



[2.7] Kruse, W.

Versuchsmethode und -verfa hren zur Ermittlung von Widerstand

und Auftrieb ebener Netz t Ucher im kleinen Anstellw1nkel-

bereich

Seewirtschaft 9, 8/1977. 471 ff.



[2.8] Hackeschmidt, ~1.

Grundlagen und Bedeutungen der Modellahnlichkeit in

der Stromungsmechanik

Maschinenbautechnik 15

(1966), H 12 S. 635 ff.



[;2.9] Kruse, W.

Ergebnisse zum Widerstand und Auftrieb ebener Netzgitter-

modelle im kleinen Anst ellwi nkelbereich

Seewirtschaft 11, 1, 1979

f:.ruse, VJ.

llsue Met hode n und Ergebniss e zum Bes t immen von Strbmwngs -

kr§ftsn an ebe nen rechteckf6 rmigen Netzteile n und Netzf~de n.

Fischerei- Forsctlun g, Wissensc haftliche Schriften reihe 15

l 197 7.: 2





[ 3. 'I] Pretzsch, P.

6ere chnung von pe lagischen Schleppne tzen

Dissertat io n 1970, Universit at Rostock



[ 3.2 ] Ivanov. E.P.

Analytisc he L6sung der Aufgaben der Statik der Fischerei netze

Fischerei- Forschung 11 (1973) 2 So 19-31



[3.3] Stengel, H. und Fridman, A.L.

Fischfang gerate

VEB Verlag Technik, Berlin, 1977



[3.4] Leitzke, H.

Ansatz zum a na l ytischen Entwurf eines pelagisch en

Vierlasch ennetzes

Fischerei- Forschung 14 (1976) 1, S. 43-51



[3.5] Leitzke, H. und Stengel, H.

Stand und Perspekti ven der Erarbeitu ng einer Methodik

zur analytisch en Berechnun g ne tzartiger Fanggerat e

Seewirtsc haft 11 (1979) 5, S. 242-244



[3.6] Baranov, F.I.

Selected Works on Fishing Gear.

Vol . I, Jerusalem 1976 ISBN 07065 1561 7



[ ~ 0 7] Hirschle, H., PfeiferJ P. und Lan ge nbach, E.

Untersuch ungen zum Schleppw iderstand und Entwurf eines

pe lagischen Netzes

Dornier-S ystem-Be richt, 1980



[3.8] Lange, K.

Schleppw iderstand von Tau werknetze n

Hansa 116 (1979) 4, S. 319



[3.9] Stopperka , W. und Pretzsc h, P.

Analytisc he Entwurfsm ethode fOr pelagisch e Schlepp netze

(Un tersuchun g von Steerten)

Seewirtsc haft 3 (197 1 ) 1, S. 65



[3.10] 0 a l c h ovJ, K • u • a •

Bewegung sverhalten und dynamisch e Beanspruc hung von

Schleppne t ze n

Dornier-S y st em-Berich t Nr. 106/7 4, 1974.









-· 1 '· ') ...

SCALLOP DRAG TESTS AND DEVELOPMENT

by: Alan J. Blot t and Vern on E. Nulk









The sea scall op, Plaeope~tin mage llanic us, fishe ry is an impo rtant

of the Unite d State so

segm ent of the fishi ng indu stry of the East Coast

musc le only) worth about

In 1979, 31.5 milli on pound s of meats (the addu cter

ls are invol ved in the

$103 milli on were lande d. Over 200 documented vesse

scall op gear, calle d

fishe ryo However, studi es have shown that comm ercial

nt effic ient, dep endin g

scall op drag s or dredg es, may be only 10 to 20 perce

ach 20 percent~ In

on scall op s i ze; and gear -rela ted mort ality may appro

ive betwe en 3 year old

addit ion, prese nt gear with 3 inch rings is nons elect

mm respe ctive ly. Between

and 5 year ol d scall ops, appro xima tely 62 and 106

scall ops quad ruple s , so

the ages of 3 and 5 years old, the meat weigh t of

migh t incre ase yield per

gear which selec tivel y fishe d for the older scall ops

that incre asing the ring

recru it sign ifica ntly. Inve stiga tions have shown

but fishe rmen have argue d

size does decre ase the catch of smal ler scall ops,

using large r rings would

that becau se of the large amount of trash caug ht,

that chang ing to the 4 inch

be ineff ectiv e. One Cana dian inve stiga tor concl uded

tive, so he sugg ested

ring would no t make the drag sign ifica ntly more selec



devel opme nt of an entir ely new piece of gear.

scall ops are force d into

Studi es on gear -rela ted mort ality have shown that

m distu rbanc e by drags may

mud under the drag or crush ed on hard botto m. Botto

broug ht up in the gear

reduc e the settle ment of spato Unde rsized scall ops







- 121-

are dumped, culled, shoveled, and exposed to extremes of temperatu re, thus



reducing their chance of surviving when returned to the water.



In spite of all the investiga tions conducted to date, there are many



unanswere d questions remaining . The Northeast Regional Management Council



realized it would be difficult to manage the scallop resource unless more



were known about the gear used in the fishery; therefore , a study was funded



to look at the New Bedford scallop drag using divers and color underwate r



televisio n.



The purpose of the initial study in the summer of 1979 was to. develop



the technique s for divers to ride the 8 ft. drag and handl e the camera and



lights. Also, it was hoped that methods of determini ng mortality , selectivi ty,



and avoidance could be worked out during the initial stage. After the diveTs



became familiar with riding the dredge, they were able to ride and handle the



camera. One diver aimed the camera and another tended the electrica l cable.



The diver operating the camera was directed by a coordinat or watching a video



monitor on the vessel who was in voice contact with the diver~





Another method was developed where the camera on a two wheel trolley was



lowered down the towing warp after the drag had been set. Using the trolley,



observati ons can be made without diverso While looking for areas of bottom



suitable for towing or for concentra tions of scallops, the camera, with a



pole sticking out in front of the lens, was lowered on a line to the bottom.



As the boat drifted~ the line was adjusted so the end of the pole just touched



the bottom. Also, a net and frame were construct ed to attach to the top of



the frame of the scallop drag t o catch any small scallops which exhibited



the reported avoidance behavior of swrmming up over the top of the drago









-122-

The use of t he coJoT underwater television camera and dive rs for



ob servin g the operation of the dredge at 1 1/2 to 2 knots worked welJ .



However, in the 9 days a\a ilable in 1979, the correct combination of sha llow



depth , good vis ibilit y> ;-n nl a dequate concentrat ions of sca llops ~va s POt

found so most of the observati ons wer e of dredge performance not scallop



behav i or ..



It was found th at t he bai l of the drag t owed at an angle so th e tow JO int



was up to 4 ft. off the bottom, and the cutti ng bar--the lower horiz ontal



membe r of the rigid f rame at the mou t h of tl1e dr ag--was always severvcrc omc. s om e of t h~~-~ nroblems . Th e first c on cern is t o redu ce gear--rcJ at e el



mort ;:L ] i t y hy c lwngi n g the rear sec t i on of the drag .. Th e f orward f ra me- ~ ork





\v] 11 close Ly rc~;c mb .l l' that of ex ] st]:ng New 13edford drags. TJ1e depr essor p l a te



wi ll be J.argeT ;m d hinged so t he ang l e of attack will be a djust a bl e .. By c han gi n g





the depressur ang le, th e downward force on the dr ag will be a lt ered .. A bolt - on



cutting b a r ~i ll be u se d so differ e nt cross-se ctional s h apes can be t es ted.



Th e s hap es being consid e red in cl ud e a qu arter cir c l e whi c h is intended to



d eflect wa ter flow down to the se a bottom to di s l o dg e sca llop s laying i.n



depressj on s.. J\no t her shape is on inv ert ecl h _ clrofoi 1 , which may 1 ift the

v



scca ll o ps sho uJ cl be r ed uce d .



The top ;md ly•t t d m ·.;t"C'cl mes h p







of krill .







THE ENV IRONMENT - A CHALLENGE TO BE CONQUERED







The waters around th e Anta rct i c ar e known t o be the worJ d's

most difficu lt for nav i gation. The ve ssels opera tin g i n

thes e la titu d e s mus t be sa fe , effici e nt and sea worthy.

The pr ob lems which one ma y meet there are not only the gales

and fo g but also i cebergs, l ow temperatures a n d dr if ti n g ice .

Even i n summer the krill ar ea s could be covered wi th flo .:Jt."Lr-li:J

pack-i c e. The period of open water i s short , only a few months.

To len gth e n the catrhing se aso n of th e kr ill vesse l it has t o

be de siqned to oper ate and cat ch also J.n ice cr:J ndj_ tion s.

Figure 1. Typical view of the Antarct ic seas in

winter. The waters of South Orkney' s

are surround ed with icebergs and thick

pack-ice .









Figure 2. The ice pressure on the hull demands a

special construc tion and design of the

vessel. This figure is taken on the trip

of Wartsila - built icebreak er "Almira nte

Irizar" near the South Orkney's in

Octob e r 1.9 7 9.







-'~0-

A typical picture of the krill area in winter time is as

shown in fig 1., which is taken near the South Orkneys Island s

last October. The drifting pack-ice covers the sea with a few

icebergs here and there. For conventional fishing vessels

it is impossible to operate safely in these waters, because

the rapidly changing ice conditions can demolish her easily

making the hull plating wrinkled as a raisin. The ice thiknes s

and the ice pressures can be imagined seeing fig.2 which is

taken only abt. twenty miles off eastward South Orkneys.

(The figures 1. and 2. are taken during the trip of the

\i-Jartsila - built Antarctic icebreaker "Almirante Irizar"

last October at the Atlantic sector of krill areas.) The icy

env ironment of the far- off southern krill are quite similar

to those of far-off northern seas of Finland. The Finns have

succesfully navigating during winter time for over a hundred

years and have gained experience second to none of ice operatin g

vessels. Now it is time to use this knowledge also for the

starting of winter operations in krill areas.







ICE-OPERATING KRILL FACTORY TRAWLER







Operation in these circumstance s require special vessels,

which are not only capable of overcoming the environmenta l

threads but also can carry out their main task: the harvesting

of krill. Wartsila has developed a ship to operate in these

waters . Comb ining the vast icebreaking and polar navigation

know-how with the experie nces of ic e trawling has made in this

vessel capable of cop ing with the Antarctic challenge.

Th e main characte r istics of the vessel can be seen in figures

3 and 4.

She is a stern trawler wi t h the possibility of lowering the

warps under the ice, featuring a tot ally covered trawl deck

and is equipped with the Wartsila air bubbling system to

reduce the ice resistance.

Figure 3. Krill factory trawler for operating in icy conditions

of the Antarctic. The J.ength of the vessel exceeds

100 mcl c:rs and she rc~ s e mbles more an icebreaker than

a tra\vl er.









1

The a rtist. 1 s impressj on of \1\'artsila s design operating

in the hnt d rct.ic ,,\ 1aters. 'These vessels should harv e~:; t

k r j 11 a 1 ~;; o i n win t~ e r t_i mc s .

-1~2-

These featur es are standard s olutions for an ic egoing

fishing vessel, but this one has also several other fe a tures

which put h e r in class of her own when conside ri ng op8 r at j o nal

cha racte risti cs in the Antarctic. With h e r engin e powe r s h e

is capable to go through an field of two feet th ic k ice

maint a ining a trawling speed.







BRIN GI NG THE HUGE KRILL CATCHES TO THE MARKET





The mo st attrac ti ve aspec ts in catc hin g of the krill are

the huge potentials of krill and the relati ve easiness of

catc hing . From the large krill s warms, a daily catc h of

several hundr ed tons can be retr ieved. The processing capacit y

of the W~rtsil~'s design i s up to 200 ton s krill per day.

The proc e ssing of krill is concentrated into three major

products: peeled krill, krill meal and krill oil. The

processing of all these products has deve loped rapidly

within the last year, and the proc e ss ar e available for usage.

Because the products compatible with products of to-days

market of s mall shrimps, fish meal and fi s h oil, there should

be no maj or problems in introducing them to the mark et.





The main purpose of the vesse l is to catch and proc ess krill,

so the cargo space is not des igned to carry a ll the products

of one trip onborad. Th e ship is capable for indepe nd e nt

oper ation u p to three months, after whi c h a transport

ve ssel suppl y the factory, take the products and bring the

replaceme nt crew.









,.,. ., /

- I '

'· '

~

t





Krill flowi ng throu gh a peele r. The pee ling tests have

given prom ising resul ts in last years .









tai l

Peele d krill is small of size but can be used as cock

shrim ps or raw mate rial for "kril l pins" etc.







-'~""'-

r w••• •• :-.. ._

f!



...

••



.. .









Members of Wartsila Shipyards at ice-going trials of the

icebreake r "Almirante Irizar" on the Antarctic waters in

October 1979 .









Icebreake r "Almirante Irizar" built by Wartsila Helsinki

Shipyard having the high Finnish ice-going know-how to

ensure the operating in t he Antarctic water both in summer

and winter times .



- 135"-

..

Latest deve lopment on gear instrumentation

by Peter S tewart



Dr~ Peter Stewart informed the meeting on the latest develop-

me nts in gear instrumentation for trawl engineering studies

at the Marine Laboratory (Aberdeen)s

At the mo m nt a new type of underwater loadcell and a net

e

speed log wit h a 12 hour recording capacity are under develop-

men ts

The devel opment of a spreadmeter and otterboard instruments

measuring the angles of heel, tilt and attack is completedo

Deck loadc ells and headline height meters are commercial

availablee

Dr . Stewar t called attention to a new shackle-type of loadcells

In the dis cussion several applications of doppler-log and

wi reless netsounder were mentionede









-136-

~ODEL EXPERIMENTS ON ROPE TRAWLS, SCALE 1 4

by: Ba van Marlen



1. Introdu ction

In Septemb er 1978 and July 1979 trials were done on 1/4th scale

model s in the vicinit y of Sardini a.

This researc h was a co-oper ative programm e of the Institu t f~r

Fangtec hnik in Hamburg , Wa Germany and the Netherl ands Institu te

for Fishery Investi gations in IJmuide n, Holland .

The main objecti ve was to make picture s and films of several rope

trawl models and to do measure ments in order to compare these with

the full scale trials done aboard the FRV "Triden s" on similar

nets in Novembe r 1977 and 1978o

Seve ral constru ction problem s were dealt with, like the cutting of

the "shark teeth" at the junctio n of the ropes to the adjacen t

netting panels and the design of the shape of the frameli nes and

the lengths of the ropes.

Direct observa tion is the only way to find out the extent of dis-

tortion in parts of the net~ The area chosen waa very suitabl e

for this purpose . A very nice sea tempera ture combine d with a

good visibil ity made the working conditi ons easy for the divers~

Other requirem ents were a calm sea state and a sandy bottom for

bo ttom trawl experim e nts not mention ed he re. The depth of the sea

bed should not be much over 15 meters.



2o Gears tested

The models, scale 1:4, were derived from a 1736 meshes pelagic rope

t rawl {see figures 1 and 2) on which extende d tests have been done

in the years 1977 and 1978 (see referen ce)o

The shape of the frameli nea is based on the catenar y curve leading

to the rope lengths given in the drawing~

In additio n to this gear a similar net with a meshed upper square

has been studied *

The second model was identic al but for the front part, the design

of whi ch has been done with a compute r programm e especia lly

written for this purpose~ This routine calcula tes the length of

the ropes and the frame-l ine section s using the assumpt ion that

the ropes are equally loaded and the elongat ion could be neglect ed

( a correct ion of elongat ion due to a nominal load has been taken

into account when constru cting the net)o

The dimensi ons of these rope panels are given in figures 5 and 6.

The mesh/tw ine-size scale factor has not been kept constan t over

t he full length of the nets 9 because some small-m esh net materia l

was not availab le at the timeo For panels IV to VII this scale

facto r was chosen at 1/2 instead of 1/4 , leading to a reducti o n

fuctor for the number o! meshes in normal and twine directio ns of

1/2, in order to scale the twine area proport ionally with the

facto r (1/4)2 = 1/16.



Nm = ~~~ mostly:/ cia =~ ]

O(d = twine diameter scale factor

in this case 1/2

Hence: N

m

=m *

~ Nfs =>[ 1 • N

2 fs



The position of floats on the headline of the models is given in

figure 8. The magnitud e of floatatio n has been scaled down accor-

ding to the scale factor of forces, weights, volumes, etc (=(1/4)3)~

leading to a certain amount of floats of a given diameter and

buoyancy .

2

The S~berkr~b doors of 4o7 m were scaled down to the size (1/4t~

scale) and the weight. Even the centre of gravity of both doors

was kept in accordanc e with the full size ones. Other parts of the

rigging were scaled down to the size rather than the weight,

except for the bridle weightse

Several ways of cutting the "shark teeth" have been tried., The

best results were found with cutting C (figuPe 7), based on the

method of cutting used at the V. E.B. Fischkom binat at Restock

(see Chapter 6).



2 ~- ~~~~~~ - !~~~~~s~~

The experime nts on the scale models were done on small fishing

boats around Sardinia , an area perfectly suitable for underwa te r

filming ..

The following paramete rs were measured during the trjals:

- towing speed

- port and starboard warp load

- headline height

- dep t h of the headline

- door sp r ead

- wing - end sp re ad

- wing - end he i ght

- se c t io n height (at junction of ropes to netting)

- the depth of the seabed

200 Kc transduc ers were placed on the headline centre, the starboard

wing - end, at t he junction of ropes to netting and on top of the

starboard doo r. The warp loads were measured with 500 kg load

cells attached to the warps and the ship. The speed was measured

with an Ott - log , mounted on a special strut to keep it well away

from the ship 9 s hull s Direct observat ions were done by a team of

divers from the German Navy, in collabor ation with the Institut

f~r Fangtech nik in Hamburg, under the guidance of ing~ W~ Horn?

who took most pictures and films. Changes to the gear could

easily be made by the divers without the necessity ~o heave upg

The effec t of tide and currents was judged to be neglecta ble,

no rec i procal courses wer e sailed. The technique used for full scale

measurem ent has been described in reference (2) and (3) to a great

detail and will not be mentione d heree



~! -2~~E~~~ ~~~ - ~f - ~~~~ ! - ~~E~~~~~~~~-~!!~-f~~!-~~~~~-~~~~~!~

4o1 o Rope trawl with meshed upper square

The full scale values are higher over the range of speeds used~

irrespec tive of the bridle weight, although with 750 kgf weight

the differ e nce decrease s with speed. Both the wing-end spread a s

the headline height are bigger in full scale, the differenc e being

largest with 750 kgf bridle weightw







- 138-

The door spread did not mat ch the full scale value~ indicating

the model do ors being hydrodynamic al ly l ess efficiento

These results agree with the drag of the model being considerably

bigge r than the comparative full scale valueo The more drag a

gear has the less it opens. In figure 12 the drags of two models ar e

plotted against speed together with the full scale values of the

rope trawl with the meshed upper square ~ At 4.0 knots the model wi th

the meshe d upper square has 70% more drag, at 5 .. 0 knots the diffe -

rence turned out to be 60% a



~.2. Rope trawl wit h floatation 1 catenary shaped headline

The wing -e nd area is plotted against spe ed in figure 13 for the

600 kgf weight case and in figure 14 for the 750 kgf case.

Both show the same tendency, the wing-end area of the full scale

trawls is considerably larger (some 40% at 4Q5 knots)o

~he addition of 150 kg bridle weight on each side had a similar

effect on both model and full scale trawl ss The wing-end areas

are increased by some 5% .

With 600 kg the headline height dimin ished at th e same rate for

model and prototype, but with 750 kg the full scale gear seemed

to have a headline height , that reduces faster when incre asin g

speed. The differences in wing-end area decrease slightly with

rising speed, but the rate of change is not very much dependent

on the magnitude of the we ight s on the lower wing-ends (figure

15 and 16).

The discrepancies in drag are not as large as with the trawl with

meshed upper squarem The model results seem to be rather sensitive

to the length of warps pa id out, in contrast with the full scale

values, where this dependancy is not so distinct. At 4eO knots the

model has 15% more drag and with 5 knot s the difference rises to

38% (figure 17).



5. The effect of floatation on the compu ter designed rope trawl

----------------------------~--------------- - ------------------

In figure 18 the wing-end area of the computer designe d rope trawl

is plotted against speed, for two differen t values of the bridle

weight. The influence of the floats on the headline i s hard to

distinguish . At low speeds the no-floats condition seems to lead

to larger wing-end areas, whereas at 5~5 knots there is no

difference at all, irrespective of the bridle weights used.

The model floats were chosen in order to scale the buoy ancy in

the right order and not the size, and therefore not the drag.

This may account for the undistinctive results at high speeds~



6. Results of direc t observation

A lot of information can be learned from direct observation o f

the gears, either by taking pictures or filmsa

The rope trawl with meshed upper square did not show any significan t

distortion, apart fr om the pieces of netting used to connect the

top panel to the sides~ It can be clearly seen from figures 19a -g,

that this netting is much too slack. The overall shape of the net

looks quite well. The netsonde cable and the wing-e nd trans ducers

can be distinguished on figure 19g.

Figures 20a-j show det ails of the compute r designed r op e trawl

without floatationo The shape of the trawl is very well indeed,

with the attachment point of ropes to netting almost in one

perpendicula r plane .. The "sharkteeth" cutting of the to ppanel

(see figure 8 and 20h,i~j) gives the least distortio n, that of

side and lower panel considerably moreo









- 139-

A simi lar desig n of the topp anel cutti ng is there

from a net shape poin t of view . It is based on fore favo urab le

havin g a narro w

band of smal ler mesh es, at the junc tion of rope

s to netti ngo

From figur e 20d it can clea rly be seen , that the

strai ght line secti ons along the fram eline s is assum ption of

a valid one.

There seem to be no sign ifica nt diffe renc es in

net shap e betw een

the comp uter aided desig n and the desig n based

shap e. on the caten ary

Fina lly a scale mode l of the Sube rkrub door s (4.7 2

is show n in figur e 21, with a trans duce r on top m full scale )

(200 KC) look ing

acro ss to the othe r door . In most case s the door

s were heel ing

inwa rd and were tilte d back ward s.



Refe rence s

(1) Mode londe rzoek aan gesle epte vistu igen

RIVO, TO 77-0 8, Augu st 1977 , Bob van Marl en



(2) Rope traw l deve lopm ent

RIVO, TO 78-02 9 May 1978 , Bob van Marl en



(3) Rope traw l deve lopm ent - furth er expe rime nts

RIVO, TO 79-03 9 May 1979 , Bob van Marl en and Davi

d N~ MacL ennan









-140 -

TABLE OF EXPERIMENTS

1. Rope trawl with meshe d UEEer sguare 2 caten ary headl ine, no floats

I I







Scale Bridle warp - bridle

Haul

~xtension {m)

_"!-' _ _ _ _ _ _ _ _ _

!~!:~~~-~~! ~~!~!!~~-~~sr>

------·- ..· -

no.

- -~--------~-

1:1 4.4 450- 650 600

T78/2 ,3 6oo

VF79/1 1:4 4.4 300

1:4 2.4 400 600

VF79/2

T77/2 ,3 1:1 4.4 450-650 750

T78/5 ,6 1:1 4.4 550 750

VF79/3 1:4 2.4 400 750





2. Rope trawl with floata tion 2 caten ary shape d headl ine

) · I I I I



Scale Bridl~ Warp- Bridl e

Haul

no. exten sion (m) !~~6!~-~~2 ~~!s~~!_i~sr>

------~~-- .. ---.-------- ----------- 600

T77/15 111 4.4 450-650

1;1 4.4 550 600

T78/9 600

T78/10 1:1 4.4 550-850

1:4 4o4 400 600

VF78/6 400 600

VF78/7 1:4 2.4

T7?/12 ,1,3 1:1 2.4 450-650 750

T78/? ,8 1:1 4.4 550 750

T77/14 1:1 4.4 450-650 750

VF?8/8 1:4 2.4 400 750

VF78/9 1:4 2.4 600 750





de~isned , roEe trawl

~- ComEu~e~ floa t

Scale Bridl e Warp- Bridl e

Haul

exten sion (m) length (m) weigh ts

no.

_____ ____

..., i~5!2 __

-------~--,..- ----------- ----------

VF78/2 1:4 4.4 400 600 yes

1:4 2.4 400 600 yes

VF78/3 600 no

VF79/6 1:4 2.4 400

1:4 4.4 4oo 600 no

VF79/8

1:4 2.4 400 750 yes

VF78/4 yes

VF78/5 1:4 2.4 600 750

1:4 2.4 400 750 no

VF79/7

U/- ' 1-'EI~ - h>,·D L0 i-./ .:.: .,....: -/-"r~· ;...::.= .._..

.





TDTRL LEN'c:TT H ;-/£RoL /vE

R!V.!J FD.IJTR OPE.









Ben :J ming

F fG.·.i RDP E- TRA 'NL

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___ ___ ____ -~:_F....:.. '_"_L ·;~-~ sffiLl:~:_= ~- -

-~_--_ :t{~t~· - ~000 -:/200 1-('/: Fo rm aat







B IVO - TECH;. ./ 'RES. lJEP. --~~~- l -~-'. _S:~rr__G_ec_o:~~-e_e·r_d-;=--·---?-A-4_...~__7

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Geteken~ /t..r.6..c.-'"r Gez.icn .E'/-!tJ-7J' R~ npchikmerk

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(SCALE .

Gccontrol ccrd

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Form aa t



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-144-

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-- _ __ _ J _ _ _ _ L _ _ _ _ _ J _ _ _

_ cF-Jt'JEL-5

Z~KAI\JTEN



fMARSW'UDTE

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BOVENKflN

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ONir.~ --- -- - ----- - - -

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~1:-- -------- ------- ----

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- . ... , c ,.--...--- - --

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____ _____ ____ ___ _

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- ~ - - - - - ~-- · ·- -- -- -- __

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l.Lh\ X!Ef 3 CDf1PR ~ l Sim OF riD DEL EX PER I~IDHS HTH

! FULL SCALE RESER2CH

RDPE TRR~JL WITH MESH[] UPPER 5f~UfiRE.

50fl K5. BR 10L[ W .

l E5HTS nu SID T~15

r.~J HRRPLEN5HT : J30-5~Z H. # =T'/B/2



ll/5jll~ RREA .

$=T78/3

H

B.tt~ ( M2) f 15. : 3



% =VF79/I

&= 2

Vfl9/









t%---------~+---, - ---- 11 ---- ----~-------- ----- --~

-

~ V. ~



M

. ~

. ~

.

~ T T ~





SPEED (~ND15)









- 150-

F15 . : 10

I.!J.r f. I.,, 3

rtl V

L'i

CDMPRRISQN OF MODEL T S1 HITI1 FULL

E S SCR~E RESEHRCH.

f·~ OPE TI~H IJL ~!I TH t1E5HED UPP[R 5W.JRRE ( 1735 H[SHES)

V.([ 7~0 KG. BRIDLE WEIGHTS.

H?!:R WRRPLEN5TH : Y0 0 - ~~0 M .

EX T. Y. ti ~L l : I ; 2. Y M I : ~

.

5CHL[ I: I

#~ =T77 /2

~ =T77/3

% =T7H/~

R ::T78/5







5CRLE I :~

0 =VF79/3









IJ 'T"J

t:. :w-

HLL VFtUES rnu! VR~DH FULL 5CRLE ! ! ~







r1 ~.:-

LL V =T78 /5

# =178 /6

FIG. 12. '.DRAGS vs. SP~ED

(-··) ; FULL SIZE "rf\LUE









- 153-

·---...,- -

KNOT S

·-·- -·-- -------· - - - - -

~~ I 5-. · 13

X!Bt 3 CDM PRR I SDN OF MCJDEL TES TS ~-J I TH FUL L

SCALE EXPERIMENTS.

ROPE TRAWL WITH FLOATATION.

500 KG. 6R IDLEWE IGHT5.

~J R RP L E f\1 G T H : l!0 0 ---B S" 0 f1 .



FULL 5CRL E

..u-

""tt" ~ ·7 j ,. 1,~_

r· -~

I

_,

.t" :::-:T 78/9

% :==T 7fJ / l 0







5C fiLE I : l-1

->-~ ::-:: VF.7 B/5

#

+ ~yF~7B/7









B.~









H.12+



RLL VFH ~ U ES EQU l VAL ENT F UL L SCA LE.





~ . ?i~ ------------T-~-- ----- ~ ·1---- - ------- ---- -----t-··· ·- ·- - -----~ --r----------------

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m ~ ~ Ill

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f'l :r :r

5PE ED [ L T E ~1 T 5 V 5 . rU L L_

5(f-i LE

R LJf~ [ T f~ f-H·J L ~~ I T H F L 0 R T 5

51~0 KG. ER l DLE t-J E I GHT ~-J

~.. j H F: p L E h! G T H : L~ [i 0 -·· Ei s 0 t1 .









f-~ULL 5CF iLE

c l1. ) # -:. T 7 ·; I l S:

$ ::::T-/ E1/9

% ~ T7E~/ I r~





5(R LE I : t~





r2l :.-: VF7E 1/Ei

[~ -;;::V r:· 7 [~I 7









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- 156-

H/L F l 5. ; 16 M0 r.> EL. T E: 5 T 5

RDPETf~ Rt·~L

V 5 . FlJ L. L ~i ( H L.. t:

t·J IT H ~-LOHI HT I[! N.

75:0 KG. BR l D LE~,J[ I 5HT 5.

~-J R RP L~ E ~J 5 T H : LJ 0 0 - GS: [J t1 .

EXT . 2.Li1 1. / Y.L~ M.





FULL 5( HLE

# :::=T7~/ I I 2

:t~T77/l3

;:, :-: T -;-; / I L1

& ~T-1£1/7

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-1 57-

Fl G. f7 DRI-16 S VS . SP [ ED

RO fE -TRA\vL \JITH FL

Of1TATION

Cf-1TENARY SH!lP ED HEADUN E

( . . ) = FULL SCALE VALUE









----------------

~ ~









{.L§ .O

250









:f **

U£8

200

·· * ;::. VF78/6

'T





w t =VF 78 I 7

__J ~·= VF 78 !8

et

u ~-

Ln == VF 78 I 8









I+ ::=. T 7 7/1'2

X = T7 7/. 13



LU

* == T 77 I 14

V1 :=: T 7 7I 15

N

(. /}

+:::: T7 7/ 16



_j

_I

0 =T 78 /7

=:i ® -= T7 8/ 8

LL A =T 78 !9

~ == T78/10



Cf%~) - -- ---2-:01(4~ o)- --- - ·-

--- --- -- 25-rc

- 158-

s. O)S r r~ ED--- -------3.0 I(6. 0 ) - - KNOTS- - - -p

-· " - ·----···- - - - ;r-

... ·--- -- -

- .......

r:--1 5 .. 18





t--J I ~,Jl:l--Et'-ti> FH~ER VS . SPEEC>t BF~ IDL E

kJ E I [; H T R ~H> F L 0 T H T I 0 ~~ .

5 CR L E I : L ~ CfJ t· f- 1 U T E R

1 [ >E 5 I r- ~ .n=: D R [J P t-:: T f\ F1 I·!L .









NO FLfJF1T HT I DN



:f1== ~--: VF ·; H / ;; ~~ : ~ V F 7 :l I E

~ :.::VF~-/H/3 ~ ~-:: VF -/9 / [j



l2J :-: V r-- 7 H / lf ra :-: v1-- -; ~l / 7

G1 :.7! VF-·; H/ ~









F1 Fl :r 1fl L1

5P [ED E IRAwL 'WITH MESHED

GlPPER- SQUARE ~ . SCALE \ ;4









FlG. : 19 b

FRONTVIE UW









FlG.: 13c.

VIEW FRON ABOVE

STAR.'BOARD SrDE

~~~~~~ AG. : 19 d.

SI'DE \/IEU.'N ROPE S 10 NETT ING









AG.J9g FRONT viE\tJ

wtTH IRANS DL{CE R_S

ON 'Wti\JG- END AND

HEA'D LINE

FIG.: 2.0

CCMPUTER. 1>ESlGNED ROPE

JRAWL

NETNOUTH FRONf VIEW









R6.: 20a









FIG.~ 2..0b









FlG.:20c









-- 1~2 .

FlG.: 20e

STARBOARD SI])E "PANEL









FlG.: 2.0 f

LOWER 'PANEL









AG.: 20g

STARBOARD SIDE '""PANEL

COHPUTER J)ESIGNED

R.OPE TRA\VL

SCALE l: 4

TOPPA-NEL WtTH

SHA-RK IEETH









Fl6.:20i..









FlG.~ 20j

/-









FlG. : 2.1

SCALE HODEL OF .SUBERKRUB DCOR

(Lc7 rr?· Ft.(ll .Sco.le.) wtTI-i IRANSDL -tCER ON

JO'P

3. Recommendations

At the end of th meeting the convenor raised the question of the

next meeting place and asked suggestions for a 6peoial topic

for the 1981 Working Group-meeting .

The Committee Chairman Dr. Ge Kurc invited both the Engineering

and Fish Reaction Working Group to meet simultaneously in

Nantes (France) from 4-8 May 1981. This invitati on was accepted

with thanks

Next in the discussion on the special topic it was not9d that

in general far too less attent ion ie paid by the Working Group

on low-en rgy fishing ethods. It was further noted that some

member countries have r a arch in thia field plannedG

The meeting accept d therefore the following recommendation :

In iew of th continuing concern about the sffGct of the

high cost of energy on fishing activities,

it is recommended that the Workins Group on Res@aroh nd

Engin ering Aspects ot Fishins Gear, Vessels and Equipment

should aeet in Mantes from 4-8 May 1981, to consider in

particular low energy consumption fishing methods, recent

develop ente in this field and requirements for futur

research.









~166-