Source: HSE
HSE investigations into the collapse of two tower crane jibs has identified that there were problems with adequate maintenance of the slew brake release mechanisms.
The purpose of the safety alert is to advise owners and users of steps to be taken to ensure that tower crane slew brake release mechanisms are maintained in an efficient state, in efficient working order and in good repair. The emerging findings from the HSE investigations indicate that the operational efficiency was compromised by lack of maintenance, in particular, insufficient lubrication of the slew brake release mechanism. This alert provides supplementary information to HSE Health and safety bulletin FOD 2-2014Preventing catastrophic failure of luffing jib tower cranes in high winds
Full Safety Alert: http://www.hse.gov.uk/safetybulletins/tower-crane-slew-brakes.htm