Reducing crane fatalities
Lessons from Losses 6/2009. Small steps to avoid fatal casualties.
Lessons from Losses 6/2009. Small steps to avoid fatal casualties.
A load lifting operation by a tower crane was beginning at a construction site. Inadvertently, one of the shortening hooks of a chain sling grabbed a temporary rail of a balcony.
The rail structure was ripped apart up by the crane due to high vertical forces, and the loosened metal elements started to tip down before altogether collapsing.
One of the elements of the rail structure hit an employee working underneath, who suffered a fatal head injury. His hard hat could not withstand the impact but was broken by the rail element. Due to obstacles and darkness, the driver of the crane did not see the position of the hook and the lifting tackle.
Fig. 1 Shortening hooks used in lifting.
Fig 2. The metal wire net of the temporary rail system that was grabbed by the hook.
Shortening hooks are used in lifting tackle to make necessary adjustments to the length of the chains, thus providing stability when lifting loads. Unfortunately, hooks that are not in use can fasten to loads and structures causing failures and–more importantly–accidents.