cranes/Portal cranes are cranes
objects by a hoist
which is fitted in a trolley.
uses cables, winches and pulleys to lift and move containers by its lifting
(& hence the hoist) can
move horizontally on a rail or pair of
rails fitted under a horizontal supporting beam called jib or boom or
beam is supported by (vertical) uprights, usually with
wheels at the foot of the uprights allowing the whole crane to traverse.
hoist is a device used for lifting or lowering a load by means of a
lift-wheel around which rope or chain wraps. It may be manually
electrically or pneumatically driven and may use chain, fiber or wire
its lifting medium. The load is attached to the hoist by means of a
Gantry crane runs on a track at the floor
level along the length of a factory
and can provide three
axes of hook motion i.e. movement of whole crane along
the length of the building, trolley
(& hence the hoist) movement across the width of the building
/down movement of lifting hook. However,
gantry cranes are also
available running on rubber tyres so that tracks are not
Gantry cranes are generally
available in spans to 150 feet and capacities to 150 tons
portal cranes may have only a fixed gantry, particularly
are lifting loads such as railway cargoes that are already easily moved
can be either of Single Leg type or Double Leg type.
Cranes usually span a smaller portion
of the work area as compared to a
/ Portal/Goliath Cranes are adapted to applications where overhead
runways would be
very long, costly to erect, and difficult to maintain in alignment.
installation is only temporary, a gantry crane can be moved to a new
with less trouble or expenses than an overhead crane and its runway.
Also it is
comparatively easy and inexpensive to extend the length of the runway
increase the working area of the crane. Most gantry crane installations
are outdoors. The initial cost
of a gantry crane, which may be double that of
an overhead crane, must be equated against the additional cost of an
gantry crane provides the same performance characteristics that an
bridge crane offers.
famous gantry cranes built in 1974 and 1969 respectively, were Samson and Goliath,
in the largest dry
in the world in Belfast,
Each crane had a span of 140 metres and lifting capacity of 840 tonnes
to a height of 70
metres, making a combined lifting capacity of over 1,600 tonnes! .
The world's biggest 1600 t gantry crane was installed in Hyundai
Heavy Industries Ulsan plant, South
Korea in year 2009.