Cranes are commonly used in the construction of towers and industry, and in manufacturing heavy equipments. Cranes ranges from small site crane to big cranes and deck cranes that lift heavy equipments. Basically, they are temporary structures in construction. They are either fixed on the ground or hoarded on a purpose-built vehicle. Cranes come in different types such as jib, gantry, ship and deck, bridge or overhead, boom, tower, and mobile or truck.
Before operating the crane, operators should carefully read and understand the operation manual from the crane manufacturer. Further, they must always note any instructions given by a reliable instructor or operator. It is also crucial for the crane operator to understand the consequences of careless operation of cranes. They must be instructed of the proper use, prohibition and the safety rules and regulation during the operation.
It is always the responsibility of the owner to make their personnel aware of all federal rules and codes so as to preclude violations along with their penalties. Employers must also make certain that their operators are properly trained and are equipped with the know-how. To be safe in the operation of crane, it requires skill and exercise of great care and ideal foresight, alertness and concentration. Also strict adherence to proven safety rules and practices is necessary.
The personnel who handle the operation of cranes in an area must utilize hand signals, if necessary, as their means of communication. Here are the most commonly used hand signals during crane lifting operation:
- HOIST. Raise the forearm vertically and extend the right arm straight out with forefinger pointing up. Then, move hand in small horizontal circle.
- LOWER. Forefinger pointing down and extend right arm downward then move hand in small horizontal circle.
- STOP. Extend right arm down with wrist bent, palm down and open.
- SWING. Right arm away from body, point with finger in direction of swing of boom.
- RAISE BOOM. Fingers closed and thumb pointing upward while extending the right arm straight out.
- LOWER BOOM. Fingers closed and thumb pointing downward while extending the right arm straight out.
- BRIDGE TRAVEL. Extend the right arm forward, hand open and slightly raised and make pushing motion in direction of travel.
- TROLLEY TRAVEL. Thumb pointing in direction of motion with palm up and fingers closed, jerk hand horizontally.
- EMERGENCY STOP. Extend right arm, palm down and move hand rapidly left and right.
- MULTIPLE TROLLEYS. For block marked 1. hold up one finger, and two fingers for block marked 2. Regular signals come next.
- RAISE BOOM and LOWER LOAD. Right arm extended and thumb pointing up. Flex fingers in and out as long as load movement is needed.
- LOWER BOOM and RAISE LOAD. Right arm extended and thumb pointing down. Flex fingers pointing in and out as long as load movement is needed.
- DOG EVERYTHING. Hold hands in front of the body.
- MOVE SLOWLY. One hand gives any motion signal while the other hand motionless in front of hand giving the motion signal.
- MAGNET IS DISCONNECTED. Spread both hands.
When using these hand signals be sure that you and the crane operator are familiar with these signals. A wrong signal could cause a serious injury or worst – death.
Always stay alert when you are working in construction near any crane. If possible, avoid working under a moving load and stay clear of the counter balance. Always use your safety devices and helmet to avoid injuries. Safety is always the top priority of all workers and the crane operator.