CABLE COMMUNICATION.

New Zealand Herald, Volume XLV, Issue 13647, 15 January 1908, Page 8

CABLE COMMUNICATION.

HOW THE WIRES WEAR.

WORK OF REPAIR-SHIPS.

[BT TELEGRAPH. —OWN CORRESPONDENT.]

Wellington", Tuesday. ! The Tutanekai will leave Wellington this evening to repair the. fault in No. 2 cable from Oterangi Bay. to the South Island. The - fault is about 12 miles from the northern end, and five or six miles of cable will be taken on board the steamer. It is anticipated that the work of repairing the fault will not fake more than two or three days. A representative of the Post was shown several pieces of electric cable by Mr. J. K. Logan, inspector of telegraphs, that had been lifted from the ocean bed whilst locating faults. The first piece produced by Mr. Logan for inspection was recovered from the middle of Cook Strait on July 6, 1907, and had been in use as portion of the cable for a, period of ,30 . years. , The cable from which the piece had been taken was threecore cable, and the portion recovered was in' a remarkable state ' of preservation, even the outer sheathing, or serving, as it is technically named, and which envelopes the steel protecting ' wires in which the cable itself is enclosed, being intact. The serving is made of tarred "hemp, and the fact of its being practically undamaged points to that portion of the cable having been laid on a sandy or mud bottom.

Another piece of cable had ■ I ten 're-* covered when locating a break 12 nvles from Terawhiti, and bore the appearance of having been cleanly cut in a slanting direction. " This, .it was explained, had been caused by chafing on the rocks j through the' shifting, of the cable during heavy" .'-eas. Such an enormous pressure had been brought to bear that portions of the outer sheathing had been stretched, and were unbendable. Another illustration of the power of the waves was shown in the lorni of a piece of cable recovtied from White's Bay in February, 1903, which, owing to the action ox the water in separating the several strands of wire, represented the appearance of a wire birdcage. The cable staff had on one occasion, by means of the usual tests, located a fault in the landing portion of the cable at White's Bay on the beach. The peculiarity of this'fault was that it was most noticeable in damp weather, the cable ; working fairly well in dry weather. On ' the- seat of.the fault being discovered it j was found that someone had evidently been using a pick on the beach and had driven one end right into the heart of the cable, thus causing the fault. While grappling for the cable after a fault had been located by the usual tests, 13 knots from Oterangi Bay, on January 24, 1907, the cable ship picked up the cable at the exact spot where the fault existed. When examined a remarkable incident was revealed, the guttapercha having stretched about six inches, making an empty envelope, so that when the test was applied it gave absolutely no connection. Other pieces of faulty cable showed that corrosion had taken place. A fault was reported on the WanganuiWakapuaka cable in March, 1903, and on the 3rd of that month the exact fault came up on the grappling hook, and the cable broke. . It was then discovered that the fault was in the manufacture of the cable, there being a flaw in the guttapercha. This is the only faidt that has developed in the Wanganui cable, which was laid in 1880. Thus the line was free from interruption for a period of 23 years. It is explained that the Wanganui cable lies on a muddy bottom, and it is said never to have moved since it was first laid.