The telephone equipment is a standard UAX12. The only none standard feature being that the individual channel feet are replaced by two lengths of heavy channel iron extending under the whole length of the five units. Rigidity is provided by bracing the tops of the units to both sides of the body.
The C unit has a permanently connected length of cable which extends under the floor, and terminates at a detachable joint on the rear wall. This joint allows the incoming cable to be terminated to the exchange cable, the whole being sealed against the ingress of moisture, with any plumbing operations. As this joint will have to be re-made fairly frequently, and the exchange cable having to be cut back, the joint is bolted to a pair of vertical channels which extend from floor to ceiling. When first supplied the exchange cable is long enough for the joint to be at the ceiling, and as it becomes shorter the joint moves down, being attached to the channel by two bolts. At some distant date the exchange cable will have to be replaced.