CRANE :- A large machine used for moving heavy objects by suspending them from a projecting arm or beam
THREE MAJOR HAZARDS :-
ELECTRICAL HAZARDS
nearly 50 percent of overhead crane accidents are the result of machinery coming into contact with a power source during operation. Power line contact is literally defined as the inadvertent contact of any metal part of a crane with a high-voltage power line. Power line contact most often occurs when the crane is moving materials nearby or under energized power lines and the hoist line or boom touches one of them. Usually, the person who is electrocuted is touching the crane when it comes into contact with the power line. But, the danger is not just limited to the operator. It extends to all personnel in the vicinity.A single contact with power lines can result in multiple deaths and injuries.
Preventive measures :-
The area within a 10-foot radius of a power line is considered an unsafe work area—or danger zone—and it must be clearly marked on the ground by insulated barriers, fences, tape, etc.
OVERLOADING
80 percent of all crane upsets and structural failures can be attributed to exceeding the crane’s operational capacity. When a crane is overloaded, it is subject to structural stresses that may cause irreversible damage. Swinging or sudden dropping of the load, using defective components, hoisting a load beyond capacity, dragging a load and side-loading a boom can all cause overloading.
Preventive measures :-
workers to provide formal training for all crane operators, but operator certification is only required for operators using equipment with a maximum manufacturer-rated capacity of 2,000 pounds or less. Employees who are not qualified are only permitted to operate equipment as operators-in-training with a certified trainer. Formal training should ensure a working knowledge of crane load charts, and on-the-job training is a great preventative measure if the trainer is qualified.
MATERIALS FALLING
Falling materials is a major concern at any work place or job site using overhead cranes. Visual impairment, two-blocking, slipping, mechanical failure, or operator incompetency can all result in serious injuries or fatalities. If materials are not properly secured, for instance, the load can slip and land on workers in the vicinity or cause major damage to property. For larger or mobile cranes, undesired movement of material can pinch or crush workers involved in the rigging process.
Preventive measures :-
One way to reduce the risk of falling materials is to perform regular maintenance of hoists. Load testing maintenance ensures that you know how many pounds the hoist can handle, and it helps to maintain good working condition. Maintenance should always be treated seriously when it comes to heavy machinery. If a moving part on an overhead crane wears out or breaks the hoist, it can cause serious damage. Performing regular maintenance ensures the hoist and overhead crane remain in good working order and that all operations run smooth.
DUTIES WHILE WORKING ON THE CRANE : -
1.While working on the crane the operator should see that proper lighting is ensured.
2.Before leaving the crane cabin for any purpose the operator must bring all the controllers to the neutral position cut -off the switch in the cabin.
3.Mobile cranes should be parked on hard soil or strong base . This should not be placed near the edge of the pit or excavation.
4.No unauthorized persons are allowed on the crane.
5.No inflamable materials are kept on the crane. 6.Capacity marking as stated above should be displayed on the crane.
7.At least two winding ropes should always be on the wire rope drum of the crane.
THE CRANE SHOULD NEVER BE PUT INTO OPERATION
1.There is crack in structure. 2.There is damage in the wire rope 3.Hook does not rotate freely or the locking nut on the hook is missing 4.Coupling bolts/pins or their nuts or leather/rubber bushes missing. 5.The power collector is touching the adjacent trolley lines.
6.Rubber material or the wooden platform from the crane cabin is missing.
7.Earthing connections from the controllers and other electrical equipment missing.
8.Any unauthorized lerson is near the power line or on the crane.
SITE SUPERVISION :-
Sitesupervision has overall responsibility for the lift. Supervision must plan all phases of operation cooerating fully with the operator who has the final say regarding the safety of the operation.
SITE SUPERVISION IS SPECIALLY RESPONSIBLE FOR :-
1.Verifying that the crane certification and inspection records are up to date before allowing the crane on the project.
2.Organizing a pre - lift meeting and ensuring all the appropriate people are present.
3.Establishing a lift plan and ensuring it is followed.
4.Determining the correct load weight and radius and informing the operator.
5.Ensuring that an emergency response plan is in place and in communicated to all relevant personnel.
1.
Telescopic crane
: -
ATelescopic crane offers a boom that has a number of tubes that are fitted inside each other.
Then hydraulic mechanisms extend or retract the tubes to length or shorten the boom.

:-
This is the most basic type of crane and consists of a steel truss or telescopic boom mounted on some kind of mobile platform. this platform could be wheeled a rail or even a cat truck . the boom is hinged at the bottom and can be raised or lowered by cables or hydraulic cylinders.

:-
These type of cranes are mounted on a rubber tire truck and provide excellent mobility. the outriggers will extend vertically or horizontally and are used to stabilize and level the crane when it is hoisting a load of materis.

Tower crane :-
A tower crane is considered to be a modern form of a balance crane. when fixed to the ground this type of crane will often give the best of height and lifting capabilities. they are also used when constructiong tall buildings.

:-
The crane is mounted on an undercarriage that has four rubber tires and is designed to be use off road . the outriggers can extend vertically and horizontally to stabilize and level the crane when it is lifting a large load. these types of cranes are single engine meaning that the same engine is used to power the undercarriage and the crane.
Overhead crane
:-
These types of cranes are also known as suspended cranes. they are generally used in a a factory and some are able able to lift very heavy loads .the hoist of the crane is set on a trolley that will move in one direction along a beam sometimes two beams. they move at angles to the direction along the elevated or ground level tracks. the tracks are usually mounted along the side of an assembly area.

:-
This is a hydraulically powered crane that has an articulated arm that is fitted to a trailer . a loader crane is used to load equipment onto a trailer. the crane can be folded into numerous sections and will fit into smallspaces when not in use. the crane can easily transported beecause of its capabilities to folded.