This document discusses various types of equipment used for hoisting materials against gravity, including chain hoists, mobile cranes, winches, jacks, tower cranes, and gantry cranes. Chain hoists are a popular mechanism for lifting loads up to tons and work by transmitting force through two sets of chains. Mobile cranes are used in large construction projects for heavy lifting, while tower cranes are mounted on high steel towers for building construction. Gantry cranes are indispensable in factories and workshops for transferring machines and components between work areas.

1. 
 SUBMITED BY-AMIT
SARKAR
 ROLL NO.-25901317123

2. 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.

3. The common equipments used are as follows:
 Pulley and sheave block
 Chain hoists
 Mobile cranes
 Winch
 Jack
 Shear leg
 Tower cranes
 Whirler cranes
 Derrick cranes
 Gantry cranes

4.  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.

5.  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
 (2)screw geared
 (3) spur geared
 (4) pull lift

7.  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.

9.  A winch is a mechanism in the shape of a
cylinder or drum, over which rope or chain is
wound.
 If a winch is used only for raising and
lowering, it is sometimes referred to as
hoist.
 The winches are of two types :-
 (1) hand winches
 (2) power winches

11.  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
areas.
 The ground area required for such cranes is
very small.

15.  The Gantry cranes or overhead cranes are
the indispensable machines in factories and
workshops.
 In large workshops, there are separate
machines for fabrications or repairs of the
machine parts.
 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.