Abstract: The trolley is used in a fall arrest system and comprises a frame, a channel formed within the frame for engagement therein of a lifeline, and a self-blocking mechanism carried by the frame. The self-blocking mechanism comprises a brake movable between a braking position wherein the brake extends within the channel for frictionally engaging the lifeline; and an enabling position wherein the brake clears the channel for clearing the lifeline. The self-blocking mechanism also comprises a manually operable enabling actuator connected to the brake and capable of forcing the brake towards the enabling position.

Abstract: The trolley is used in a fall arrest system and comprises a frame, a channel formed within the frame for engagement therein of a lifeline, and a self-blocking mechanism carried by the frame. The self-blocking mechanism comprises a brake movable between a braking position wherein the brake extends within the channel for frictionally engaging the lifeline; and an enabling position wherein the brake clears the channel for clearing the lifeline. The self-blocking mechanism also comprises a manually operable enabling actuator connected to the brake and capable of forcing the brake towards the enabling position.

Abstract: The elevator work platform assembly comprises a base movable over ground, an intermediate platform, a first stairway pivotally linked to the base and the intermediate platform and leading from one to the other, a work platform, a second stairway pivotally linked to the intermediate platform and the work platform and leading from one to the other, a linkage pivotally linked to the base and the first and second stairways, and an actuator capable of actuating the linkage and first and second stairways to move the work platform between a collapsed position in which it is adjacent to the base and a deployed position in which it is located away from the base. The stairways have self-levelling steps to allow access to the work platform in all positions thereof between the collapsed and deployed positions.