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 intermediate support device is used for supporting an intermediate portion of elongated element such as a lifeline. The intermediate support device comprises a frame which is to be fixedly attached to an external structure, and a wheel comprising a hub rotatably carried by the frame and a number of peripherally spaced-apart spokes fixedly attached to and radially extending from the hub, the spokes defining a common first channel side and a common second side opposite the channel side. The frame comprises a frame guard in facing spaced register relative to the spokes first channel side and having an edge portion adjacent the spokes whereby the wheel and the frame guard form a substantially closed loop defining a channel therethrough on the spokes first channel side, for allowing the elongated element to extend through the channel.