Vane Tempest Colliery - LONDONDERRY COLLIERY

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					                         LONDONDERRY COLLIERY
              (The Sinking of the Vane Tempest Colliery)

This new winning, consisting of two pits, known as the Vane and Tempest
pits, is being sunk for the purpose of winning and working inland and
undersea coal lying on the north side of a large fault which intersects the
Seaham Royalty, practically dividing it into two equal portions.

                                               The fault, which runs in an
                                               easterly     and     westerly
                                               direction, is a "dipper" to
                                               the   north.          In   the
                                               vicinity    of   the    Seaham
                                               Colliery it has a throw of
                                               105 feet, while near to the
                                               coast it has a throw of
                                               upwards of 600 feet.       The
                                               coal measures dip normally
                                               to the east at the rate of
                                               about 2 inches per yard.
                                               Between the new winning and
                                               the fault the measures dip
                                               in a southerly direction 9
                                               inches     per     yard     or
                                               thereabouts.
                                               The site of the new winning
is 350 yards west of high water mark and 70 feet or thereabouts above this
datum.
The following workable seams will be passed through in the pits:

The   Five Quarter   …   251 fathoms from the surface
The   Main Coal      …   278     “     “    “    “
The   Maudlin            287     “     “    “    “
The   Hutton             309     “     “    “    “
The   Harvey             336     “     “    “    “




Maudlin and Hutton Seams have to some extent been worked to the Seaham
Colliery. Workings were abandoned some years ago for economic reasons.
The new pits will be 200 feet apart, each having a finished diameter of 21
feet. The south, or Vane pit, will be the downcast and chief coal-drawing
pit.
The north, or Tempest pit, will be used as an upcast, also for the raising
and lowering of the workmen and for coal-drawing.
The first sod was cut by Lord Castlereagh on December 19th, 1923.
A trial borehole was in the first instance put down to prove the thickness
of the water-bearing strata, which was found to be 485 feet, of which k25
feet consists of magnesian limestone with 40 feet of sand between the base
of the limestone and the coal measures.
The water met with in the foring was found at "sea level" to be salt and
that it altered in level to an extent of 3 feet with the rise and ebb of
the tide, thus indicating that the fissures in the limestone communicated
with the sea.

Having regard to the large feeders of water likely to be met with in
sinking through the Permian formation, also the nature of the yellow sands
as disclosed in the trial borehole, together with the close proximity of
                                 the winnings to the sea, it was decided to
                                 freeze the measures.
                                 A contract was entered into with Messrs.
                                 The Trefor Boring Co. and the Franco Belge
                                 Freezing and Sinking Company (both Belgian
                                 firms),   who   are  acting   jointly    as
                                 Contractors for boring and sinking through
                                 the Permian formation into the coal
                                 measures For the purpose of freezing, 33
                                 boreholes were decided upon for each pit,
                                 32 being spaced out at regular intervals
                                 around an outer circle of 30 feet diameter
                                 for freezing purposes, the remaining hole
                                 being bored in the centre of the pit for
                                 inspection purposes during the process of
                                 freezing.
                                 Prior to the boring the pits were sunk 39
                                 feet 6 ins. in diameter to a depth of 16
                                 feet for the purpose of fixing guide tubes
                                 for the boring and to admit of connections
                                 for freezing tubes with the necessary
                                 valves, etc.

                                 A concrete platform was laid around each
                                 pit at the surface level having a radius
                                 equal to the full length of the boring
                                 derricks and their engine houses.     Five
                                 concentric   rings  consisting  of   flat-
bottomed steel rails were partly embedded in the concrete at regular
intervals to facilitate the removal of the derricks from one hole to
another.   Three boreholes are bored at one time.
The boreholes were bored from the surface with an 8 in. diameter H-shaped
chisel provided with chambers on either side through which the boring water
could be discharged.
The rods attached to the bits were hollow, having an inside diameter of 2
inches to allow passage for the flushing water.
The water used for flushing purposes was pumped from the sea by a turbo
pump placed upon the beach.    The water used in boring rarely appeared on
the surface, evidently disappearing in the fissures.
The 8 inch diameter holes were bored to as great a depth as was possible
(generally about 300 feet) when they were altered to holes of 6 inch
diameter.     The holes were lined with steel tubes which were afterwards
withdrawn to permit of the insertion of the freezing tubes.
With the exception of the centre hole all holes were bored to a depth of
535 feet, thus penetrating into the coal measures 50 feet.
The greatest distance bored in one shift of 8 hours was 150 feet.       The
average rate of boring, including the insertion of the tubes, was
approximately 42 feet per day of 24 hours.
Boring operations around the Tempest pit began on October 29th,
approximately 42 feet per day of 24 hours.
Boring operations around the Tempest pit began on October 29th, 1924 and
finished on September 9th, 1925.
Boring around the Vane pit commenced July 1st, 1925 and finished February
11th, 1926.
For the purpose of freezing, as each borehole was completed an outer tube 5
inches in diameter with the bottom end sealed is lowered into the hole.
Inside this tube is inserted another 2 inches in diameter with the bottom
end open. These two are coupled up to cast iron collecting pipes with
branch pipes and valves which encircle the shaft in the freezing cellar.
The collecting pipes are coupled up to the intake and return pipes to and
from the refrigerating house.
After the insertion of the freezing tubes the lining tubes were withdrawn
from the holes.
The freezing machinery is in three units, each unit consisting of steam
driven double acting compressors with ammonia vaporisers and condensers.

The total freezing capacity of the three machines is 450,000 negative
calories at 20 degrees Centigrade.
The freezing operation is as follows :-
The brine, consisting of .25 solution of calcium chloride which- has been
                                                    previously cooled, is
                                                    pumped into the intake
                                                    main by double acting
                                                    steam pumps.            It
                                                    passes down the inner
                                                    tube in each hole and
                                                    returns    through     the
                                                    outer tube, extracting
                                                    heat from the strata in
                                                    its passage. The brine
                                                    returns       to       the
                                                    vaporisers,    in    which
                                                    are     placed       coils
                                                    containing         ammonia
                                                    liquid which vaporises
                                                    at    a      very      low
                                                    temperature, where it
                                                    is cooled and returned
                                                    to the boreholes.      The
                                                    vaporising      of     the
ammonia is obtained by means of gas pumps which create a depression causing
vaporisation.       The ammonia gas is pumped through a water cooler
serpentine where it is liquified and returned to the vaporisers.




The freezing of the Tempest Shaft was completed and sinking operations
commenced l6th February, 1926.     The shaft was sunk from the surface to
within 10 feet above water level, 26 feet in diameter, to admit of walling
18 inches in thickness.    A water garland was laid at this point and the
walling carried up to the surface. The space        behind the brickwork was
carefully packed with boiler ashes. At a depth     of 48 feet a large cavity
was encountered in the limestone which crossed     the shaft and exposed the
freezing tubes on the north and south sides.This   was filled up solidly with
concrete to prevent any surface subsidence.


Upon completion of the walling, sinking was resumed, the shaft now being
approximately 23 feet in diameter.   The ground was found to be well frozen
and the sinking quite dry.     At a depth of 109 feet the first cast iron
tubbing curb was laid and the tubbing built upon it up to the walling.
The cast iron curb was of the box section, 1 foot 9 inches wide by 10and a
half inches deep, the metal being 1 and three quarter inches thick with the
necessary strengthening ribs.   16 segments form a complete circle.
The tubbing is 2 feet deep, likewise 16 segments forming the circle of the
shaft.    All the courses were laid upon yellow pine sheeting 3/8th of an
inch in thickness and the full width of the tubbing flanges.        Sheeting
was likewise inserted in the vertical joints.
As the tubbing was built up the: space between it and the wall sides was
packed with sand and gravel from the beach. Upon completion of the tubbing
all joints were wedged with pitch pine wedges, until a chisel could no
longer be inserted.
Sinking was again resumed, and the shaft tubbed and wedged in four more
stages, as described above (with the exception that the space behind the
tubbing was filled with concrete) until the position of the main wedging
curb was decided upon.
                                                    The sand was found to
                                                    be frozen a compact
                                                    mass,   and   was   sunk
                                                    through as ordinary in
                                                    strata. A suitable bed
                                                    for the main curb was
                                                    found at a depth of 585
                                                    feet from the surface,
                                                    or 50 feet below the
                                                    bottom       of      the
                                                    boreholes.
                                                    The bed for the curb
                                                    was carefully dressed
                                                    and levelled and the
                                                    first curb laid upon
                                                    it.      This curb was
                                                    similar     to     those
                                                    already       described.
                                                    The space between the
                                                    back of the curb and
the wall sides was closely packed with timber, the grain running
vertically.      This was wedged with pitch pine wedges until a chisel
could not be made to enter
The shaft sides were next shorn back to admit the main curb, which was 10
and a half inches deep by 2 feet 3 inches in width, 16 segments forming the
                                               circle of the shaft.     The
                                               metal was 2 and a half
                                               inches thick with suitable
                                               strengthening ribs.
                                               Yellow pine sheeting was
                                               laid upon the curb already
                                               laid, and the main curb
                                               placed upon it.    Timber as
                                               before was packed between
                                               the back of the curb and
                                               the    wall    sides,   then
                                               carefully     wedged,    the
                                               tubbing was then inserted
                                               in the ordinary way. The
                                               time occupied in sinking,
                                               wall,   and   tubbing   this
                                               portion of the shaft was
six and a half months.
The total depth of tubbing is 516 feet, the thickness of metal varying from
7/8ths of an inch at the top to 2-l/8th at the bottom.         The thickness
increases l/8th of an inch every 20 rings.       Special rings for carrying
buntons for supporting rising mains, etc, are fixed in suitable positions.
The total weight of tubbing is 1,880 tons.
The thawing of the ice wall was commenced by Messrs.The Franco Belge
Company, on April 1st, 1927.     This consisted of circulating brine warmed
by steam through the freezing tubes.     A contract for the remainder of the
sinking below the frozen ground has been entered into with Mr.H.Woodfield,
of Messrs,Howard & Woodfield, and sinking resumed March 1st, 1927.       The
depth of the completed shaft is now (May l6th) 96O feet.
The rate of progress below the frozen ground, including the insertion of
nine inch brick walling, averages 8 feet per diem.           The thawing is
practically completed and the theoretical pressure of water due to the
static head is now registered upon the gauge fixed in the tubbing.       The
sinking was delayed six months owing to the strike.
The Vane shaft is now frozen, and all necessary erections completed for the
sinking which will commence on May 17th,
The headgears, which have been erected by Messrs. Head Wrightson & Co.,
are of the lattice girder type. The height from the surface to the centre
of the pulley wheels is 80 feet.
The permanent pulleys will be 18 feet in diameter.

The winding engine at the Tempest pit is temporary. It consists of two
cylinders 26 inches diameter, with 5 feet stroke.The drum is cylindrical,
and 10 feet in diameter.
The winding engine at the Vane pit is permanent, and erected by
Messrs.Robey & Co., of Lincoln.         It consists of a pair of 32 inch
cylinders, with 72 inch stroke.        The drum is temporary, 14 feet in
diameter.    The permanent drum will be semi-conical, with diameters varying
between 14 feet and 21 feet.

The crab engines are built by Messrs.Worsley Mesnes. of Wigan, each having
two heavy cast iron drums 3 feet 6 inches in diameter, with worm gearing
and two cylinders 11 inches diameter by 10 inches stroke.
The boilers at present consist of 4 Woodeson patent water tube boilers,
each capable of evaporating 20,000 lbs. of water per hour.       The stokers
are supplied by the Underfeed Stoker Co., and are of the forced draught
type.
Two of the boilers are fitted with Woodeson's patent superheaters, and a
Green's Economiser has been placed in the main flue leading to the chimney.
The chimney is 200 feet in height by 10 feet in diameter.
The boiler plant is laid out so that another economiser may be added, as
also induced draught, if necessary.
The water softener is of the "Becco" type, capable of treating 8,000
                                                   gallons of water per
                                                   hour; the hardness of
                                                   the    water    is   thus
                                                   reduced from 22 degrees
                                                   to 4 degrees.
                                                   Ventilation     in    the
                                                   sinkings is produced by
                                                   two    "Sirocco"    fans,
                                                   having a capacity of
                                                   15,000 cubic feet per
                                                   minute, at a water gauge
                                                   of 10 inches.

                                                  They   are  electrically
                                                  driven   by  motors   25
                                                  horsepower,    each  pit
                                                  having a separate unit,
                                                  the air tubes being of
                                                  steel   24    inches  in
                                                  diameter.
The power station is at present erected of sufficient size to house one of
the permanent fan engines, and a generating set of 100 k.w., by
Messrs.Metropolitan Vickers. The turbine is of the high pressure type,
taking steam at 140 lbs. per square inch at the stop valve.     Speed 2,400
r.p.m. Alternator direct coupled 2,750 volts, 3 phase, 40 periods, cooled
by enclosed ventilated system. Multiple jet condensing plant with motor
driven air and extraction pumps. The switchboard is of the drawout truck
type.
The house will afterwards be extended to contain a duplicate fan engine,
two air compressors, and probably two exhaust steam driven turbines.
The power station is linked up with the station at Seaham Colliery, and
will subsequently be also linked with the plant at Dawdon Colliery.
A cooling tower has been erected of the Premier Cooling and Engineering
Coy.'s type, capable of cooling 230,000 gallons per hour from 100     Fahr.
Height of tower 70 feet.
A railway connection has been made with the L. & N.E.R. near to Hall Dene.
By this means practically all the material required for the new sinkings is
being delivered.
A railway will shortly be constructed on the south side of the new winnings
to connect them with the Seaham Harbour docks, at which the shipment of the
coal will be effected.
      END

				
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