OVERHEAD CONSTRUCTION
AERIAL CABLE

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Multicore underground cable was introduced early on in Telecommunications but aerial cable was not used that much. This was probably due to the cost of producing small quantities and the technology involved in hanging such a cable. The obvious way to hang a cable in those days was the catenary wire, where a steel wire is suspended, between two points and a cable attached to it.

The GPO used this idea and attached the cable by various forms including the use of a lashing machine which wrapped a wire around both the catenary wire and the multicore cable, as a continuous support.

In the 1950's the catenary wire became integral to the multicore cable and self suspended aerial cable was thus formed.

Erection of aerial cable was more difficult than small gauge open wires and specialist equipment was designed to assist.

This cable was generally used in rural areas where undergrounding cables was expensive or impossible.

Aerial cable erection at Haverford West (1944)

Hauling cable with truck
Note that this is an ex-WD vehicle
Probably pulling the suspension wire into place

Dynamometer and ratchet in place ready to be lifted into place
The ratchet tensions the suspension wire and the dynamometer shows the tension

Tensioning in progress
Dynamometer and ratchet in position
The tension is a mathematical calculation which is variable according
to the temperature of the day

Ringing in progress
The Cable Rings are spaced at 20 inches

Cable Rings

Ringing Seat

Aerial cable being pulled through the rings

Winch in place for hauling suspension wire
Note the temporary strut and stay wire supporting the pole

Cable installed and through jointed

Installing Loading Coils

The loading coils come from the factory in a steel case with two cable tails
The cases contained induction coils which balanced long cables
The case is in position ready to ne lifted into position

Hauling the loading coils into position
These loading coil containers were very heavy

Loading coils in place and fixed
Note the two tails in position for jointing to aerial cable

Aerial jointers tent
These cables are paper insulated and therefore must be kept dry

Loading coil fully installed

Cable jointing in progress
This is a through joint

Jointing Platform against pole

Jointing platform in mid span

Erecting aerial cable using a Cable Lashing machine (1954)

Lashing in progress
The two men are pulling the lasher along the suspension cable
These could also be pulled with a slow moving truck that had the aerial cable drum on the back