festoon cable system

A festoon cable system supplies power and control to the hoist travelling across an overhead crane bridge, as well as to straight monorail tracks and short material handling runs. Flat cables hang from small trolleys running inside a C-shaped steel track. As the hoist moves away the trolleys spread out and the cable extends, and as it moves back the trolleys close up and the cable folds into loops, like a curtain. System components C-track: a galvanised steel or stainless steel track fitted along the bridge girder, with the cable trolleys running inside it. Cable trolleys: four-wheel trolleys with a curved saddle that keeps the cable within its bending radius. Towing trolley: the first trolley in the line, connected to the hoist by a towing arm and pulling the other trolleys behind it. End clamp: a fixed anchor point at the end of the track, next to the crane's electrical panel. Flat cable: a cable designed for repeated movement. The flat shape lets it fold evenly and reduces twisting and internal wear compared with a round cable. When to choose it The cable gives a continuous, insulated electrical connection with no carbon brushes to wear or collect dust and dirt, so the system suits dusty and humid environments and outdoor use. With no sliding electrical contact it does not produce sparks, and also suits explosion-hazard areas when fitted with components rated for them. Power cables for the motors and shielded control cables can run on the same track. Maintenance consists mainly of periodic checks of the cable sheathing and wheels. Design consideration When the hoist reaches the end of the bridge, all the trolleys and folded cables gather at the end of the track and take up space there. This needs to be allowed for in the design, so the hook can still get close enough to the building wall. The model table lists the track size, trolley types and cable widths for each model.