The hoisting is the lifting of the
material against gravity and maybe done
with a wide range of equipments from the
small hand operated simple screw or
hydraulic-jack to modern high powered
cranes and elevators.
The common equipments used are as follows:
Pulley and sheave block
A pulley is a wheel on an axle or shaft that is
designed to support movement and change of
direction of a cable or belt along its
circumference. Pulleys are used in a variety of
ways to lift loads, apply forces, and to transmit
power. In nautical contexts, the assembly of
wheel, axle, and supporting shell is referred to
as a "block."
A pulley may also be called a sheave or drum
and may have a groove between two flanges
around its circumference. The drive element of a
pulley system can be a rope, cable, belt, or
chain that runs over the pulley inside the
The pulley and sheave blocks suitable for
lifting rough surface and heavy loads.
For this purpose the chains and wire ropes
The alloy chains are best suited for hoisting
The weakest component of this system is the
load hook. The hook fails by straightening.
Once the hook gets elongated or
straightened, it should be replaced.
A typical sheave and pulley block is shown in
The chain hoists are the popular mechanism
for lifting loads upto tones.
The system consists of two sets of chains,
namely the hand and load chain.
The hand chains are particularly useful for
the isolated location , where an electric
motor or other types of mechanical
equipments are not available.
The pull applied through the hand chain is
transmitted to the load chain with a
multiplication factor of over 20.
The load to be lifted is held by a load hook
while another hook(called support hook) at
the top, support the mechanism.
The two hooks however ,should not be
interchange as the support hook is made
much stronger than the load hook.
There are four types of hand operated chain
hoists are in use:
( 1) Differential
(3) spur geared
(4) pull lift
Mobile crane is used in big construction
projects for lifting heavy loads.
It is used for loading and unloading for
material in coal mines.
Loading and unloading of ships.
To take the load from ground level and place
it into the trucks.
A winch is a mechanism in the shape of a
cylinder or drum, over which rope or chain is
If a winch is used only for raising and
lowering, it is sometimes referred to as
The winches are of two types :-
(1) hand winches
(2) power winches
These are the crane of swing job type and
are mounted on high steel towers.
The height of tower maybe 25 to 30 m and
these cranes are found to be suitable in the
construction of tall buildings in congested
The ground area required for such cranes is
This crane is a combination of stationary and
mobile unit. This combines the advantages of
log boom of derrick crane and mobility of the
The rotating structure has an outer
The boom is attached to the front end of this
framework. The counter weight is provided
at the rear end. On the diagonally opposite
corners of the base, two separate motors are
provided, which give movement to the
The derrick cranes are of two types, namely:
(1) Guy derrick and
(2) Stiff leg derrick
The guy derrick consists of a vertical mast.
This mast is supported by the number of guys
and can revolve through 360.ﹾ
While revolving, the radius of revolution
should be such that the revolving structure is
not obstructed by the guy wires.
The power is supplied by a diesel engine or
by an electric motor.
A typical derrick crane is illustrated in fig.
This derrick can be constructed upto 200
tonnes capacity .
In stiff leg type derricks, the guy wires are
replaced by trussed structure.
This type of derricks are suitable for loads
from 10 to 50 tonnes.
The Gantry cranes or overhead cranes are
the indispensable machines in factories and
In large workshops, there are separate
machines for fabrications or repairs of the
The machine or the components, which are
to be repaired, can be transferred to the
place of fabrication or assembly with the
help of Gantry cranes.
Hoisting equipment assists in the lifting and
positioning of large, heavy loads in a variety
of industries, including:
Warehousing and distribution
Hoisting equipment provides a variety of
Customizable – Hoisting equipment can be
customized with below the hook
attachments, end effectors or specialized
tooling to handle a diverse variety of
products and loads
Ergonomics – By doing the heavy lifting,
hoisting equipment takes the strain off
operators, reducing fatigue and lowering the
risk of injury
Flexible – Hoisting equipment can be easily
re-fitted for longer lifting capability
Reduction in product damage – By allowing
for smooth, direct-path lifting over
obstacles—with soft start features, multiple
speed options and a variety of end effectors
to interface with and secure the load—
products are handled gently to minimize
Safety – Because they operate overhead and
work in a specific area, hoisting equipment
is less likely than forklift traffic to
maneuver a load into personnel, walls,
machinery or other obstacles
Hoisting equipment is used in a variety of
areas to support processing and handling
throughout a facility:
Assembly: Moving products through
Positioning: Securing a component for
Transportation: Loading finished products
onto open trailers or railcars
Staging: Holding work-in-process for
additional production processes
Storage: Transporting heavy items to and
from storage areas
Warehousing: Moving large, heavy products
to and from docks
Disadvantage of chain hoist is slow lifting
pace and limited places.
Hydraulic engine hoist can take a lot of space
Electric hoist are not good with heavier
electric hoist is that they need a special
place to be installed.
electric hoist will be static and cannot be
moved around (without special
installations), so you will always have to
place a reparable car in the same place.
Electric hoist needs to be placed above the
ground. This usually means mounting it to
ceiling or building a special scaffolding to
install an electric hoist.
Another disadvantage of electric hoist is that
it needs an electric power source in order to
work. Hydraulic or chain engine hoists need
to be operated manually, while electric hoist
has got an electrical motor that works with
an electrical power.
electric hoist is fast and convenient tool to
use for lifting moderately heavy loads, but
becomes much more expensive, if you need
to lift loads heavier than 225 kg (500 lb).
The lifting of load is also very slow in chain
This lifting process in chain hoist is slower
than electric hoists or hydraulic hoists.
The cranes used as hoisting equipments are
The climbing tower crane disadvantages:
Due to the direct support tower crane in the
construction, the need for checking the
structure, when necessary, temporary
reinforcement, increased costs.
Due to the crane installed in the elevator
shaft of the building, so the crane
installation will affect the construction
schedule basement structure. due to the
crane installed in the elevator shaft of the
building, so the crane installation will affect
the construction schedule basement
driver communication links with the ground
is difficult, driver vision is not enough open
to lifting bring some security risks.
after the project is completed, disassemble
downstairs need auxiliary lifting equipment,
difficult to disassemble, not safety.