February 2012 - Working with Jacks
Working with Jacks
Does your job require you to work with jacks? Let’s take a look at some very important guidelines regarding the safe use of jacks. Jacks are generally known as lifting devices. In order to safely lift a load with a properly functioning jack you must know two things. First, you need to know the weight of the load you wish to lift. Second, you need to know the lifting capacity of the jack. This is important because a jack used to lift a load that is too heavy for it, is highly likely to fail. This failure could result in injury or property damage. Consequently, jacks are required to be legibly labeled and label placement should be permanent in a prominent location on the jack. Labeling can be done by casting, stamping, or other suitable means. Before using a jack, make sure it is rated with enough lifting capacity for the load you intend to lift.
The jack must be stable when used in order to prevent shifting or toppling. The jack can be blocked at the base or at the lifting point (cap) to prevent the possibility of slippage and to provide a stable base for the lifting operation. Don’t try to jack beyond the jack’s stroke limit. All jacks have a limit of travel that must not be overrun. Once the load is raised to the desired height, it must be secured at once by cribbing or blocking. Jack stands are often used for this purpose. Whatever method of securing the lifted load, make sure the weight of the load can be safely supported.
There are many kinds of jacks and they all must be maintained properly. Lubrication of all moving parts is important for proper operation. Hydraulic jacks operated in freezing temperatures must be supplied with an anti-freeze liquid. Jacks must be inspected for proper service at regular intervals. Inspecting a jack before and after use is always a good practice. Any time a jack is sent out for service or is modified in any way it should be inspected for defects. Any jack that is subjected to shock or overloading must also be inspected for defects and proper operation. If a jack is used at the same shop over time, it must be inspected in six month intervals; however it is still a best practice to conduct a pre-use inspection every time it is used. If defects are found, a jack must be tagged out of service and not used until repaired.
Sometimes jacks don’t look like jacks you may have seen before. Material handling lifts often incorporate hydraulic pistons to achieve the lift. Engine hoists use lifting mechanisms just like a jack and fall under the same requirements. What about a manual hydraulic bearing press? They use a hydraulic piston to exert force. Is this considered a jack? Well maybe not, but just as with any tool, inspection and maintenance is required. Exercise caution with jacks at work and at home. Make sure they are up to the task.