Overhead cranes can be of many types according to their need and usage.
Given below are various types of cranes:
Bridge cranes are installed on metal beams that run along the ceiling of the room of the factory or warehouse. It needs two strong beams on the sides, a trolley which travels with it and carries the load as well as a hoist, which is needed to lifting and lowering the objects. These types of cranes can be again of two types.
Top running bridge cranes: These cranes run on the top of the beams. This requires quite some space above the beams for the easy movement of the crane. The installation must be planned as the rooms require higher ceilings. These cranes are stronger and can lift very heavy objects. They can be of single girder (which can lift lighter weights, up to 20 tons) or double girders (which can lift weights up to 100 tons).
Bottom running bridge cranes: These cranes run at the bottom of the beam. They reduce the available room height. They can even be installed in an already built factory. However, they cannot carry very heavy loads and can carry only up to 15 tons.
These are simpler types of cranes as compared to the bridge cranes. Unlike the latter, they operate on a single rail mounted on the ceiling. They operate by means of a forklift. They can be run from either a distance or by a car that moves behind the forklift.
The forklift can be used for lifting objects such as boxes, cartons and other similar objects. These cranes can be used in a small unit as well.
These cranes are very compact and efficient for smaller work places with limited space. One end is fixed on something stationary, such as a wall. Hinges are provided so that the crane can swivel within the room. The distance covered is quite small at about 20 feet. They carry lighter loads.
These cranes are the advanced modification of the bridge cranes. The tracks that they run on are mounted on the floor. Due to this, they can carry heavy loads as much as 350 tons. They have deep water access as well. They are mainly used for loading and unloading cargo and hence found at ports and docks.
Like the rest, these cranes are also mounted on horizontal beams. They remain at an angle of 90 degrees to the floor when they are stationary. But they can go up and down as and when required. They can be used to lift loads in a circular motion.
Operating overhead cranes requires skill and proper knowledge of safety procedures. For the proper utilization of overhead cranes, it is essential that workers and crane operators are fully trained and are completely skilled in the job. It is always to be remembered that unskilled or untrained operators not only put their lives at peril, but also cause the lives of other to be at risk.
For this reason, certain safety regulations for workers have been laid down by OSHA and US law for operating overhead cranes. Crane operators are responsible for their actions and for therefore, they must obey various rules and regulations that are in force. All employers must realize that there are different types of cranes and each crane has a different set of training and maintenance requirements. For proper operation of the crane, it is essential that the crane owner as well as the operator is familiar with its operating instructions. Amongst the foremost safety regulations for crane operators, it is essential that they possess corrected eyesight as mandated for a driver’s license. It is also essential that crane operators are able to effectively use both their hands and feet and are sufficiently tall to operate the controls of the overhead crane. Additionally, operators are expected to have proper coordination between their eyes, hands, and feet and should be free from disorders that could cause convulsion or unconsciousness.
Furthermore, as required by the new rules passed in July 2010, the US safety and health administration body OSHA has come up with new safety regulations for crane operators. Amongst the more important safety regulations are that cranes operators are required to be certified by an accredited body such as the National Commission for the Certification of Crane Operators (NCCCO). This is to ensure that crane operators are familiar with the hazards that come along with their daily routine. This will also help them to prevent accidents. Amongst the other notable safety measures require that the equipment be safely assembled. They should not collapse during or after installation and should be assembled under the guidelines of a qualified individual. Regular inspection of the crane equipment is mandatory every year. The crane should also be visually inspected after installation and also before the commencement of each shift.
Furthermore, audible warning signs are required for cranes when they are in motion. Every worker who is working onsite requires to be trained in crane warning signals so that they are aware of every potentially dangerous situation. No one should exceed the load capacity of the crane. The point is clear – loads that exceed the weight limit should not be moved at all. At the same time, if an operator cannot rig the load properly due to technical or other reasons, it should not be lifted. The crane operator should also inspect the path of the crane and check for any obstacles or people crossing the path. This should be done before the crane is operated. Additionally, the controls on the crane should be clearly marked and the operator should be very familiar with the use of these controls.
Workers should know how to evacuate the area in case of an emergency. Additionally, they should be familiar with how to handle an unexpected even such as an electrical or a mechanical failure. They should also be familiar with crane operation signs and should know how to handle the crane in event of a power failure. Additionally, workers should not wear loose clothing and also should secure their hair and jewelry. They should also park the crane safely when not in operation and lower the loads when the crane is not in use. Also, never ride on the hoist or pulley of a crane. This can be dangerous to life as just a slip could cause the worker to fall and can lead to disastrous consequences. Regulations also stipulate that workers should be familiar with using lockout procedures to avoid accidental starting or movements.
Broadly, it is essential that workers should understand signs, labels, as well a various instructions. In conclusion, the worker needs to be trained and tested before operating an overhead crane. There are other operator requirements including demonstrating proficiency in operating the crane. Once all the requirements are met, the worker is issued with a permit, and it is mandatory for workers that this permit is carried on their person and is made available upon request.