Pin from crane block sheave guard fell 25 m
- Safety Flash
- Published on 20 October 2017
- Generated on 29 August 2025
- IMCA SF 26/17
- 2 minute read
A member of UK Step Change in Safety reports an incident in which a main block sheave guard came loose from the main crane block and fell approximately 25 m to the deck below.
What happened?
The incident occurred when a container was being repositioned on a laydown area. The crane was being used, utilising the whip line and a pennant. The crane main block was not used due to the low weight of the load.
During the lift, a member of the deck crew heard a loud noise. On investigation, he found that the securing pin from a main block sheave guard had come loose, and had fallen to deck. Crane operations were immediately halted and the crane main block was brought to deck level for inspection.
The fallen part weighed 0.8 kg and fell 25 m; it landed 2 m from a member of the deck crew. This could have been a potential fatality on the DROPs calculator.
position of missing pin
dropped object
spring clip
What went wrong? What were the causes?
The sheave guide was secured by a spring clip. The crane block was supplied with this spring clip configuration. It cannot be determined if the clip had failed or was not installed correctly.
What lessons were learnt? What actions were taken?
The spring clip on the sheave guide was removed and replaced by a bolted configuration. All cranes in the fleet were inspected to ensure the same configuration was not present; if it was, it was corrected.
Suppliers were informed of incident to ensure they no longer supply blocks with this configuration. Planned maintenance tasks were amended to ensure checks are carried out on condition of sheave guards.
The Step Change in Safety ‘Safety moment’ can be found at stepchangeinsafety.net.
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IMCA SF 16/16
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IMCA SF 10/15
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