The Health & Safety Executive (HSE) has issued a safety alert to advise crane owners and users to ensure that tower crane slew brake release mechanisms are properly greased.
Lubrication is needed to enable the tower crane jib to slew freely in the wind when out of service. If the upper structure cannot weathervane, it risks being blown over in strong winds. Investigations into two recent collapses indicated that operational efficiency was compromised by lack of lubrication.
The HSE is warning owners and users of tower cranes to ensure that tower crane slew brake release mechanisms are inspected and maintained in line with instructions issued by the manufacturer. Where crane manuals do not stipulate release mechanism maintenance instructions the manufacturers should be asked to provide details.
Instruction should be provided to operators and maintenance personnel as to how slew brake release mechanisms should be checked, inspected and maintained. This should include information, where necessary, as to the type of lubrication and the frequency and method of applying lubrication to the release mechanism.
Supervisory checks should confirm that personnel are correctly carrying out their instructions and the crane is being placed in free slew when left out of service. Persons carrying out thorough examinations should also confirm the correct function of the slew brake release mechanism.