4.11 SAFE USE OF HAND OPERATED CHAIN LEVER HOISTS
In addition to any specific instructions relating to the safe use of the lever hoist issued by the manufacturer, the following points should be observed:
The lever hoist must not be used to raise, lower or sustain a load that is in excess of the SWL marked upon the lever hoist.
Do not use the load chain to form a sling i.e. it must not be wrapped around the load and back hooked, snickled or choke hitched. (See Figure 4.11-1 ) This is because doing so will mean that there is no longer a swivel between the load and the hoist and in addition the forces on the links at the point of snickle may affect the calibration of the chain.
Figure 4.11-1 Never hook back a load chain like this
The bottom hook should be attached to the load such that no part of the load is in contact with the point of the hook. (See Figure 4.11-2 )
Figure 4.11-2 Never load a hook in this manner, unless permitted and within the limitations instructed by the hoist manufacturer. Always ensure the load is applied through the saddle of the hook.
The bottom hook should not be crowded with the terminal fittings of slings. To prevent the hook becoming overcrowded, LEEA recommends that the upper end of the sling legs are connected by means of a shackle or link of adequate strength. (See Figure 4.11-3 )
Figure 4.11-3 The right way! To attach two or more slings to the hook use a shackle or link. The wrong way! Overcrowding the hook is dangerous.
The majority of lever hoists and especially the lower capacity models are designed so that one person will be able to operate the machine up to its SWL. This should be borne in mind as if it is found that more than one person is required, it is probable that either;
the load exceeds the SWL of the appliance or;
the appliance is in need of maintenance or;
a combination of (a) and (b) exists.
Whichever may be the case, an unduly high operating effort requires investigation before the lift proceeds. This is not intended to preclude the use of two persons to operate the lever hoist, which may in certain applications be found advantageous, but is to indicate the degree of operating effort normally required.
Care should be taken to ensure that the lever hoist is not subjected to shock loading.
Lever hoists should not be used in a position where they are liable to be subjected to extremes of temperatures beyond the specified manufacturers temperature limits. For example, above a furnace or smith’s forge or in severe frost, etc.
Loads should not be left suspended from hoists for any length of time unless absolutely essential and a safe system or work and/or additional safety measures are provided to reduce the risk to an acceptable minimum. Where it is as a result of a breakdown, the operative should ensure that the danger area beneath the load is cordoned off to prevent personnel from being at a risk in the event of a descending load. At no time should the operative permit either himself or other personnel to be beneath or on a suspended load.
When a lever hoist is suspended from a crane, e.g. to facilitate accurate positioning of the load, special precautions should be taken as follows:
For use with power operated cranes the SWL of the lever hoist should be reduced by 15% to allow for the higher dynamic loading.
Before hoisting the load with the crane, a short lift should be made with the lever hoist to ensure that the brake is locked.
Lever hoists should, when no longer required for use, be returned to proper storage.
Care should be taken not to drop a lever hoist. Any appliance which is accidentally subjected to this treatment should be checked over by a Competent Person before further use.