The authority reported that a Favco 350 tower crane fitted with a dual-speed drive system on the hoist drum recently failed and inadvertently went into free-fall whilst carrying a personnel box with two workers. The box dropped in free fall for about four floors before the hoist brake kicked in.
The body is investigating the accident, the cause of which it says it does not know exactly. “However, initial investigation indicates that there may be a potential risk of free fall occurring on other Favco/Favelle tower cranes due to either control system failures (including operator controls and pneumatic, hydraulic and electric systems) or hydraulics contamination,” the authority said.
The authority did say that in an emergency, the cranes could still be used to evacuate an injured worker, if an alternative evacuation procedure would be inappropriate.
