Module 4: Lesson 3: Cranes and rigging

A machine with a long projecting arm, which is used to move heavy objects from one place to another, is called a crane.

Always make sure that the rated load of the crane does not exceed the original capacity specified by the crane's manufacturer. To avoid accidents, a load rating chart with clearly visible letters and figures shall be provided with each crane, and it should be fixed at a location where the chart can easily be read by the operator of the crane. In addition, on barges, always secure mobile cranes positively.The load rating charts should have legible letters and figures.

Using a crane to hoist employers on a platform is prohibited. The only exception is when the conventional means of reaching a worksite, such as a ladder, stairway, personnel hoist, scaffold, aerial lift, or elevating platform would be more dangerous or the design of the structure does not allow employees to access the area. In such exceptions, a personnel platform may be used.

The activity of hoisting a personnel platform should be performed in a controlled, slow, and cautious manner. Wire rope, shackles, and other rigging hardware must be capable of supporting at least five times the maximum load applied. Locking devices (pawls or dogs), load and boom hoist drum brakes, and swing brakes must be engaged when the occupied worker's platform is in a stationary position.

•Always make sure that the total weight of the loaded personnel platform and related rigging does not exceed 50 percent of the manufacturer's rated capacity for the configuration and radius of the crane or derrick. •The use of machines having booms in which lowering is controlled by a brake without any aid from any other devices or equipment that slows lowering speeds is not allowed.

Cranes and derricks that have variable angle booms should be equipped with a boom angle indicator. The indicators must be placed where they can be easily seen by the operators.

It is important that the suspension system and the personnel platform be designed by a qualified engineer or by a competent person qualified in structural design. Moreover, the personnel platform should be capable of supporting its own weight and at least five times the maximum intended load without any failure.

A guardrail system should meet the requirements of Subpart M. In addition, the guardrail system must be enclosed from the toe-board to mid-rail with expanded metal having openings no greater than 0.5 inch. The installation of a grab rail inside the entire perimeter of the personnel platform is very important.

If access gates are installed in the area, make sure that they do not swing outward during hoisting. In addition,to prevent accidents, the gates must be equipped with a restraining device

Always make sure that all rough edges are smoothed or surfaced as they could injure employees who come into contact with them. Only a qualified welder who is familiar with the weld types, material, and grades is allowed to perform all the welding of the personnel platform. The personnel platforms should have a plate or other permanent markings that indicate the platform's rated load capacity or maximum intended load and the weight of the platform.

If you are using a wire rope bridle to connect the personnel platform to the load line, always make sure that each bridle leg is connected to the shackle or master link and that the load is equally divided among the bridle legs.

Master links, shackles, wire rope, and all other rigging hardware must be capable of supporting at least five times the maximum intended load without failure. Furthermore, when using rotation resistant rope, the slings must be capable of supporting at least ten times the maximum intended load without failure.

Bridles and associated rigging for attaching the personnel platform to the hoist line can only be used for the platform, necessary employees, their tools, and the materials necessary for work. When bridles and associated rigging are not hoisting personnel, they should not be used for other purposes.

Always ensure that the platform is secured to the structure where the work is to be performed. If a hoisted platform is not secured, employees should not leave or enter the platform. In addition, when the crane engine is running and the platform is occupied, the crane or derrick operator should remain at the controls at all times

Do not hoist employees if weather conditions are bad, or if any other indication of impending danger exists. If employees are hoisted and a dangerous situation arises, they should be grounded immediately and safely. Always remember, when employees are suspended on a platform, not to lift anything on another of the crane's or derrick's load lines as it could lead to an emergency situation.

Only necessary employees should occupy a personnel platform, and the platform must only be used for employee tools and materials necessary to perform the work. When employees are not hoisting, the personnel platform should not be used for hoisting tools and materials. Additionally, a suspension system should be designed to minimize tipping the platform due to the movement of workers. Moreover, the personnel platform should be capable of supporting its own weight and at least five times the maximum intended load without any failure. The activity of hoisting a personnel platform should be performed in a controlled, slow, and cautious manner.

When the crane engine is running and the platform is occupied, the crane or derrick operator should remain at the controls at all times. When a platform is being raised, lowered, and positioned, it is vital that employees keep all parts of the body inside, as doing otherwise could lead to an accident. Employers and employees should know that using a derrick or crane to hoist workers on a personnel platform is prohibited. The only exception is when the conventional means of reaching a worksite such as a ladder, stairway, personnel hoist, scaffold, aerial lift, or elevating platform would be more dangerous, or the design of the structure does not allow employees to access the area. In such exceptions, a personnel platform may be used.