Engine hoists, or mobile floor cranes, are capable of lifting very heavy objects such as engines while they are being removed from a vehicle or refitted.
The lifting arm is moved by a hydraulic cylinder and is adjustable for length, although extending the arm reduces its lifting capacity. The supporting legs can also be extended for stability, but the more that both the arm and legs are extended the lower the lifting capacity of the hoist. The safe lifting capacity at various extensions is marked on the arm, and it is important never to exceed the rated weight of the hoist.
The engine or component to be lifted is attached to the arm by a sling or a lifting chain. These too must be rated as capable of lifting weights in excess of the engine or component being lifted, and must be firmly attached before the hoist is raised.
When the engine or other component has been lifted and slowly and carefully moved away from the vehicle, it should be lowered onto an engine stand, or onto the floor. The further off the ground an engine is lifted, the less stable the hoist becomes.
Never use a hoist to lift any weight greater than the lifting capacity of the hoist or its sling or chains.