Detailed promotional film showing the processes involved in making Electric Power Cables.
Full title card reads: "Manufacture of Electric Power Cables at the Gravesend Works of Messrs. W.T. Henley's Telegraph Works Co. Ltd." Produced by British Instructional Films Ltd.
Reel 1. High angle shot of factory floor showing large rolls of copper. Two men pull a trolley loaded with these rolls. M/S of the men walking towards the camera - looks heavy. The copper is pickled in acid and washed to remove the oxide. C/U of rolls being lifted out of the acid bath. Copper wire is lowered and washed with a hose. "Grinding and polishing dies for wire-drawing." C/U of machines in operation. M/S of man at work close to these machines. L/S of factory floor showing men at winding machines. Various shots of the wire being wound onto a drum. Wire is placed in drawing machines. C/U of man at work on these machines. Various C/Us of wire being drawn, wound, stretched, etc. We see the wire leaving the "annealing furnace." A cage containing lots of rolls of wire rises up from the ground. C/U of man operating large rolling machine. Wire is stranded.
Machines in operation. The insulating paper is wound onto the wire. We see how a four conductor cable is wound together. Wire is dried and impregnated in vacuum vessels. Manufacture of oil-filled cable is illustrated. The spiral duct is made. Copper conductor is stranded around the oil duct. Insulating paper is wound around. Cable is then heated, vacuum dried and impregnated. Various processes and machinery seen. Cables are now covered with lead. "The Henley Patent Straight Through Lead Press" applies seamless lead sheathing. Panning shot of the machine. C/U of a model of the machine showing how it works. C/U of part of the machine. The cables are armoured with steel tape. C/U of the machine in operation. Panning shot of the machine. Man walks along checking that the machinery is working properly. Dolly shot working its way through quite a large area of the factory showing different processes. An oil pressure tank is connected to the cable to take up expansion and contraction caused by atmospheric temperature variations. This is put inside a huge drum of cable. Man drives a large early fork lift type truck with a large roll of cable on the back. Continued.