Mobile crane safety
Common Failures in Cranes:-
Types of Error in operating cranes
- 1) Human Error.
- 2) Machine Error.
- 90% of failure occur due to human error.
- The failures that occur due to human error for the following unsafe practices.
SAFETY IN USE OF MOBILE CRANES / operating cranes
Watch Your Clearance during operating cranes
- Clear work area.
- Proper clearance from m/c, boom or load.
- Vision should not be obscured.
- Blow horn to signal or warn.
- Understanding of signals.
Daily Inspection of Machine during operating cranes:-
- Don’t operate a poorly maintained m/c.
- Inspect clutches, brakes, attachments & wire rope daily.
- Lattice boom check.
REMEMBER during operating cranes “PARTS ARE CHEAPER THAN PEOPLE”
Don’t let the load hit the boom during operating cranes:-
- Don’t let the boom rest on or hit against an object.
- If a lattice or diagonal bracing member is broken or cracked, REPLACE IT.
- If bent straightens it.
SAFETY IN USE OF OPERATING CRANES
Working near power lines:-
- Be alert – you are working around a condition which can cause death.
- keep all m/c parts, hook block & load, fall lines – at least 15feet from Line.
- Assume that every line is hot.
- Appoint a person with a loud signal to warn the operator.
- Don’t allow anyone to lean against or touch the m/c.
- Don’t allow sling man or load handlers to hold load or rigging gears unless necessary.
- If m/c operating in arc zone, keep moving away from the line until arc breaks at least 15 feet away.
- If disengagement from the line is not possible & m/c is not on fire, stay back in the seat until power line shut off.
- If leaving from the m/c is must, leap from the m/c as far as you can.
Use of magnet for lifting:-
- Lifting magnet generators produce voltages in excess of 200 volts & present an electrical shock hazard- deploy trained personnel.
- Don’t touch magnet or load while in operation.
- Don’t let workmen get in between magnet & metal object.
- If necessary to position a load, use a dry, wooden stick.
Crane boom safety:-
- Loads must be well secured before lifting.
- Chains & slings must be of adequate size.
- The load must not catch on an obstruction when lifting or swinging.
- Avoid sudden starts & stops, Operate smoothly.
- Never wrap the hoist around the load during operating cranes. Never use discarded, worn, or damaged rope for slings
- The m/c must be level before making a lift. The hook block and fall lines can be used as plumb bob for leveling.
- Remember -a 3-degree side tilt can reduce the cap. By 50% or more.
Know your load:-
- Use a scale weight, carefully calculated weight or hook scale or a load indicating system
- Weight includes the weight of slings, gear, hook block & any overhaul weights.
- In case of lifting with fly jib installed, the weight of the jib & rigging mast must also be considered part of the load.
- The total weight should never exceed the rated capacity of the m/c.
- Avoid operating an m/c in high winds & wind blowing against the load, as it produces side load on boom & reduces capacity.
- Keep the load lines as short as possible.
Effect of centrifugal force:-
- Centrifugal force tends to increase load radius. This increase in load radius could overload the machine & cause damage. Use of tagline is recommended to control this force.
Crane boom safety during operating cranes:-
- Operating on the outrigger, beams must be fully extended as well as, so that tyre is clear of grounds.
- Do not pick loads on the main hoist and jib at the same time.
- Do not work with jib angles greater than 30deg w.r.t. boom.
- Do not increase the counterweight above than specified.
- Avoid using multiple cranes on a lift.
- Use caution when operating with minimum radius. This may damage boom backstop.
- After slack rope operation, make sure rope is properly seated on sheaves & drums.
- Never lower the boom on load beyond the point where two full wraps of load are left on the drum.
- Caution while lifting the Submerged load
- It may be saturated & weigh much time more than is expected.
- Should be raised slowly
Never stand in front of the Tyre when inflating
Battery & Radiator:-
- Never use an open flame to check a battery
- Be careful when removing radiator caps.
Types of failures in EOT Cranes:-
- Uncontrolled long/cross travel due to the negligence of the operator.
- Provide limit switch strikers to avoid derailment.
- Provide mechanical impact buffers to prevent unexpected travel.
- Lightweight small objects hindrance on rails:
- Provide skurt boards in the front and rear side of bogies to push away the hindrance.
- Over hoist protection:
- Provide a pendent limit switch to prevent over hoist.
- Short circuit :
- Provide waterproof operator cabin & guard all electrical components.