A hoist is a device used for lifting, lowering or moving a load. The lifting force is provided by means of a drum or wheel on which typically wraps a rope or a chain.
Hoists are classified by their lifting medium, power requirements, and mounting system. The lifting medium is the material that connects the load hook to the overhead body of the hoist. It is usually either a rope, metal cable, or chain.
Hoists may be operated manually, electrically or pneumatically. Manual hoists use a pulley system to multiply the operator’s lifting force. Electric or air powered hoists are easier to use and more convenient if the power or shop air are easy to access.
Stationary mounted hoists are simple devices to move a load straight up and down. The most familiar form of a stationary mounted hoist is an elevator, which is raised and lowered by a hoist mechanism.
Hoists mounted to a trolley running along a single beam or parallel rails are called overhead cranes. They provide the ability to raise the component then move it along the beam across the work environment.
Although these hoists are different in the way they move, the manufacturer’s recommended safety precautions should always be followed when working with hoists.
Hoist Inspection and Function Test
Before the load test can be performed, it is necessary to carry out a visual inspection and an operational function test to ensure that the hoist/crane controls operate correctly and smoothly and can perform the movements required in the environment the hoist is located in.
The visual inspection and function test need to be performed by a fully qualified crane operator. The visual inspection consists of inspecting the hoist load hooks and latches for cracks or deformation, the chain or rope medium for any damage to links or strands and the hoist housing and pulleys for any loose or missing hardware.
The items to be function tested include the load hoisting and lowering controls and mechanism, the slewing and movement of the hoist on the beam, and the proper operation of the brakes, clutches and all of its safety devices.
If any issues are found which could affect the safe operation of the hoist/crane during the inspection or function test, then those issues must be corrected before proceeding to the load test. Performing the load test can damage the hoist if it is not physically and mechanically sound.
Hoist Load Test
OSHA 1910.179 and ASME B30.16-2007 state that a load test must be completed for all hoist/crane installations prior to first use. Load testing should also be completed at a minimum of every four years after first being installed and whenever load-bearing components have been repaired or replaced. Using a hoist/crane system without these critical load tests can lead to dangerous safety issues and costly equipment failures.
The initial load test is typically performed by the manufacturer, however, if load testing of the hoist cannot be performed by the manufacturer, the load test can be accomplished by qualified personnel at the customer location or job site.
The load test is performed by applying a load of not more than 125% of the rated load capacity to the hoist unless otherwise recommended by the manufacturer. The load test is performed at 125% to ensure that the crane system can handle the maximum weight capacity in full operation. An inspection will be made after the load test to ensure that the hoist or its components did not incur any structural damage from the load test.
The qualified individual conducting the load test will prepare a written report of the load sustained during the test, the operations performed during the test and the results of the post-test inspection. The test report shall be kept on file and readily available to all necessary personnel.