TELEPHONIC CABLE.

New Zealand Herald, Volume LXIII, Issue 19231, 21 January 1926, Page 8

TELEPHONIC CABLE.

THE INTER-ISLAND SERVICE. SHIPMENT VERY SHOR.TLY. [BY TELEGRAPH. —OWN CORRESPONDENT.] WELLINGTON, Wednesday. The Post and Telegraph Department has been advised that the new telephonic cable that is being manufactured in England for Cook Strait is likely to be shipped from London about the end of the present month, and should arrive here about the middle of March. This cable, about 40 miles in length, will be the first of its kind in New Zealand, and will enable practically any telephone subscriber in the North Island to be put in conversation with any subscriber in the South Island.

The nature of a telephonic cable differs considerably from that of the ordinary telegraphic cable of commerce, in that the "loading" is differently applied. This loading is necessary for technical reasons in long lengths of telephonic cable, and may be applied in two ways, either bv the insertion here and there of copper coils during the manufacture of the cable, coils which become part and parcel of the cable itself, or by closely wrapping the copper conductor of the cable with an alloy of iron and nickel in strip form. The coil method of "loading" is rather delicate, and cables so loaded have necessarily to be handled very carefully, because when the coils become damaged in any way it is a more difficult matter to locate the damaged-point than in the case of a mishap to telegraphic cable. As Cook Strait is rather turbulent water, with a most irregular floor, the coil method of "loading" was abandoned in favour of the "wrapped" cable.