SEMINAR ON CRANES
B.ARCH V YEAR IX SEM
•Cranes are a broad class of construction equipment used to hoist and place
loads. Each type of crane is designed and manufactured to work economically in
a specific site situation.
•Construction cranes are usually temporary structures, either fixed to the
ground or mounted on a purpose-built vehicle.
•Cranes may either be controlled from an operator in a cab that travels with the
crane, by a pushbutton pendant control station, or by infrared or radio control.
•Where a cab operator is employed, workers on the ground will communicate
with the operator through a system of standardised hand-signals or, in larger
installations, radio systems; an experienced crew can position loads with great
precision using only these signals.
Choice of crane is made depending on:
•Purpose or nature of work- Handling ,Erection etc
•Position of work- Ground, top of structure, open yard, inside a building.
•Nature of terrain or condition.
•Capacities – load to be lifted.
•Power available- electrical, hydraulic, diesel etc.
•Speed or rate of progress of work needed & ease or comfort of
CLASSIFICATION OF CRANES:
MOBILE TOWER STATIC
•In wide spread project sites, mobile cranes provide the best means for lifting
and shifting of small to heavy loads.
•These cranes can move over level firm surfaces as well as on rough terrains.
These cranes may be mounted on crawler or wheel bases.
•Some of the mobile-type machines in their basic configuration can have different
front-end operating attachments that allow the unit to be used as an excavator
or a pile driver, or in other specialized tasks.
CLASSIFICATION OF MOBILE CRANES:
The most common mobile crane types are:
• Telescoping-boom truck mounted
• Lattice-boom truck mounted
• Heavy lift
MAJOR PARTS OF A MOBILE CRANE:
• Load hook
•These cranes spread their dead load over
larger area through their long tracks, and as
such are useful while working in unprepared
•Before hoisting a load the machine must be
leveled and ground settlement considered.
•If soil failure or ground-settlement is
possible, the machine can be positioned and
leveled on mats.
•The distance between crawler tracks affects
stability and lift capacity. Some machines have
a feature whereby the crawlers can be
•To relocate a crawler crane between projects
requires that it be transported by truck, rail,
or barge. As the size of the crane increases,
the time and cost to dismantle, load,
investigate haul routes, and reassemble the
crane also increase.
•Most crawler crane models have a fixed-length lattice
boom. A lattice boom is cable-suspended, and therefore
acts as a compression member, not a bending member.
•The boom of these cranes comes in sections which are
joined by pin connections. The straight boom thus formed
can lift loads over a radius of 30 to 40 metres.
•Crawler cranes in the low to middle range of lift capacity
have good lifting characteristics and are capable of duty-
cycle work such as handling a concrete bucket.
•Machines of IOO-ton capacity and above are built for lift
capability and do not have the heavier components required
for duty-cycle work.
•The universal machines incorporate heavier frames, have
heavy-duty or multiple clutches and brakes, and have more
powerful swing systems.
TELESCOPING-BOOM TRUCK-MOUNTED CRANES
• There are truck cranes that have a self-
contained telescoping boom.
• Most of these units can travel on the public
highways between projects under their own
power with a minimum of dismantling.
• Once the crane is leveled at the new work site,
it is ready to work without setup delays.
• If a job requires crane utilization for a few hours
to a couple of days, a telescoping truck crane
should be given first consideration because of
its ease of movement and setup.
• Telescoping-boom truck cranes have extendable
outriggers for stability.
• In fact, many units cannot be operated safely
with a full reach of boom unless the outriggers
are fully extended and the machine is raised so
that the tires are clear of the ground.
• There are three common power and control
arrangements for telescoping-boom truck cranes:
1. A single engine as both the truck and crane power
source, with a single, dual-position cab used both
for driving the truck and operating the crane.
2. A single engine in the carrier but with both truck
and crane operating cabs.
3. Separate power units for the truck and the
superstructure. This arrangement is standard for
the larger capacity units.
LATTICE-BOOM TRUCK-MOUNTED CRANES
•The lattice-boom truck crane has a full
revolving superstructure mounted on a multi
•The lattice-boom structure is lightweight.
This reduction in boom weight means
additional lift capacity, as the machine
predominantly handles hoist load and less
weight of boom.
•The lightweight boom will give a less
expensive lattice-boom machine the same
hoisting capacity as a larger telescoping-
•The disadvantage of these units is the time
and effort required to disassemble them for
•. In the case of the larger units, it may be
necessary to remove the entire
superstructure. Additionally, a second crane is
often required for this task.
•These cranes are mounted on two-axle carriers.
•The operator's cab may be mounted in the upper
works, allowing the operator to swing with the
load. However, on many models, the cab is
located on the carrier.
•These units are equipped with unusually large
wheels and closely spaced axles to improve
maneuverability at the job site.
•They further earn the light to their name by their
high ground clearance, as well as their ability to
move on slopes of up to 50 or 70%, depending
on the particular make and manufacturer.
•Most units can travel on the highway but have
maximum speeds of only about 30 mph. In the
case of long moves between projects, they
should be transported on low-bed trailers.
•Many units now have joystick controls. A joystick
allows the operator to manipulate four functions
•The all-terrain crane is designed with an
undercarriage capable of long-distance highway
travel. Yet the carrier has all-axle drive and all-
wheel steer, crab steering, large tires, and high
•It has dual cabs, a lower cab for fast highway
travel, and a superstructure cab that has both
drive and crane control. The machine can,
therefore, be used for limited pick-and-carry work
•By combining job-site mobility and transit
capability, this machine is appropriate when
multiple lifts are required at scattered project
sites or at multiple work locations on a single
•An all-terrain machine can be positioned on the
project without the necessity of having other
construction equipment prepare a smooth travel
way as truck cranes would require.
These cranes consist of a boom and counterweight,
each mounted on independent crawlers that are
coupled by a stinger. This configuration utilizes a
vertical strut and inclined mast to decrease
compressive forces in the boom.
•Gantry cranes are most often found in ports
and railroads, where they unload and move
huge containers off of ships and trains.
•The bases are huge crossbeams which run on
rails, so lifted containers can be moved from
one location to another.
•Capacities-60, 75, 100, 120 Tonnes.
• Tower cranes are extensively used in
building projects, specially in high rise
construction sites where work
concentration is in a limited area.
• Tower cranes provide high lifting height
and good working radius.
• These advantages are achieved at the
expense of low lifting capacity and limited
mobility, as compared to mobile cranes.
• The three common tower crane
1. a special vertical boom arrangement on a
2. a mobile crane superstructure mounted
atop a tower or,
3. A vertical tower with a jib.
NOMENCLATURE FOR A TOWER CRANE
• The base is bolted to a large concrete
pad that supports the crane.
• The base connects to the tower, which
gives the tower crane its height.
• Attached to the top of the mast is the
slewing unit -- the gear and motor --
that allows the crane to rotate.
• On top of the slewing unit are three
1. The long horizontal jib (or working arm),
which is the portion of the crane that
carries the load. A trolley runs along
the jib to move the load in and out
from the crane's center.
2. The shorter horizontal machinery arm,
which contains the crane's motors and
electronics as well as the large
concrete counter weights.
3. The operator's cabin
CLASSIFICATION OF TOWER CRANES
Tower cranes of vertical tower with jib type usually fall within one of two categories:
1. Top-slewing (fixed tower) tower cranes
• Have fixed towers and a swing circle mounted at
the top, allowing only the jib, tower top, and
operator cabin to rotate.
• Setting up and dismantling top-slewing tower
cranes requires more time, is more complicated,
and can be a costlier procedure.
• Suitable mainly for shorter-term service of low-
2. Bottom slewing (slewing tower) tower cranes
• Have the swing circle located at the base, and
both the tower and jib assembly rotate relative
to the base.
• Bottom-slewing tower cranes essentially erect
themselves using their own motors, in relatively
short and simple procedure.
• Commonly serve high-rise buildings
Depending upon the nature of the primary task, the tower cranes can be
grouped into following types:
1. Stationery cranes
2. Travelling cranes
3. Climbing cranes
•These are supported on
•Their mast is bolted to a fixed-
position steel base placed on top of
the foundations and their ballast
counter-weight rests on the base.
•These cranes can go up to 100
meters in height and are mostly used
for high rise buildings.
•The height of these cranes can be
increased further by suitably bracing
the mast with the structure of the
•The steel base of these cranes is mounted
on travel-gear, resting on rail tracks
embedded in the foundation.
•This enables the crane to travel along the
•The load travelling cranes can be used for
constructing long buildings, and shifting
heavy materials like precast elements, and
batched concrete from the production site
adjoining places or transportation areas.
•These cranes are positioned on solid cores like the lift shaft inside a multi storey
•Initially about two storey of the building are constructed by placing the crane
outside the core on a selected part of the building foundation.
•The crane is then positioned in the core by securing it with special collars,
resting on the walls of the core.
•Thereafter, the crane erects the building around itself, and climbs up when the
mast supported on the collars is raised by winches or hydraulic jacks.
•Climbing cranes are economical and are specially useful where the shortage of
sufficient external space around the building does not permit the erection of other
These are also known as derrick cranes. They are mainly of two types:
1. Guy Derrick
2. Stiff Leg Derrick
•This consists of a mast supported by
a number of guys.
•This can revolve through 360 degree
so that revolving structure is not
obstructed by the guys.
•The crane is operated by diesel
engine power or by an electric motor
•These cranes can be used up to 200
STIFF LEG TYPE DERRICK
•In this type of static crane the guy wires are replaced
by trussed structure.
•This type of crane can lift loads from 10 to 50 tonnes