CITY TELEPHONES.

Press, Volume LXI, Issue 18364, 23 April 1925, Page 8

CITY TELEPHONES.

RECENT DISLOCATION OF SERVICE. PROGRESS OF IMPROVEMENTS. When iu Christehureli about the middle of December last, Mr E. A. Shrimpton. Chief Telegraph Engineer, gave a representative of "The Press" some particulars regarding the Christchurch telephone system, and the improvements in hand, and in view of the dislocation of the service as the result of last week's storm, a reporter vi3iled the automatic telephone cxehango yesterday to ascertain what progress is being made with the scheme of improvements and what delay, if any, was likely to occur in carrying out the scheme as the result of tho recent partial breakdown of tho service. As to the recent dislocation of the service, it was found that insulation troubles explained tho disabilities which many Christehureli telephone subscribers on the automatic exchange have experienced since tho storm on the 16th inst. Tho automatic system is one of many delicate adjustments that are easier put out of order than is the case with tho manual system, and the existing conditions under which the automatic system is being worked in Christehureli aro such that with a downpour of rain like that which deluged the city last Thursday, troubles are unavoidable. Tho manual system, being less sensitive, can "bullock through" under conditions that make it impossible for tho automatic 'phones to work effectively.

By the courtesy of tho Post and Telegraph officials tho reporter was shown over the automatic exchange, and the Chief Mechanician explained tho workings of tho' system. The main causes of the troublo were, however, outside the exchange, though its results wore noticeable in it. Two pieces of lead sheathing which protect tho subscribers' wires inside the ovorhoad cables carrying a greater •or lesser number, wore submitted for examination. Thero were several irregular and difforentsized holes in each piece, and also evidences of ojeetrolysis. As the rosult of the cables swaying in tho wind parts of the lead sheathing becomes crystallised, and in time loak3 occur which admit moisture, with tho result that inBulation is impaired, and tho delicate mechanism in tho oxchango may be subjected to a tremendous overload of current. When an isolated portion of a cable is affected as above described, the fault can be electrically detected and located; but if several portions in close proximity are affected much" difficulty is experienced, in locating them all. Last Friday morning no fewer than thirty cables in different parts of the city were found to bo affeetod, the immediate result of which was that much of the apparatus, and the reSources of tho staff in _ the exchange, were very seriously taxed. The indoor staff got busy on Friday morning on tho work of repairing the exchange mechanism, and the outdoor staff, in the meantime, located the faults, and, where necesßary, temporarily . repaired the lead sheathing. On Friday morning over 500 automatic connexions had to be cut put while repairs were being made. Tho rapidity with which the repair work has been done can be judged from tho fact that yesterday morning the number of connexions remaining cut out was only 37. To add to the difficulties of the staffs, tho cables carrying large trunk linos to the St. Albans sub-exchange, which arc in common channels, also developed faults, The underground cable was rushed into use on Friday morning from the terminal man-hole in Hereford street; fortunately this portion of tho underground system . had been just completed. By 9 a.m. on Saturday the trunk connexions affected by the faulty cables were transferred to the underground system. With tho completion of the work of placing all the telephone wires underground tho possibility of a recurrence of the present troublo with the automatic connexions will disappear. In respect of the other cables in different parts of the city that have bocn found faulty temporary repairs havo been completed, thus making them availablo for use. Ultimately, permanent repairs will be carried out, and the faulty lead sheathing will be replaced as required. There is no question that the staff of mechanicians at the automatic exchange have been doing their utmost' to get things put to rights. Some of the men worked over fourteen hours daily, with half an hour, or three-quarters of an hour, for meals; and did so for two or throe days running. The outdoor staff, though not able to work such long hours, as their operations can only bo carried on during daylight, has done its share in getting things p.ut to right as expeditiously as possible. Tho permanent solution of the problem will come, of course, with the placing of all the telephone cables underground, thus doing away with tho overhead cables that have been up for many years, and are showing the effects of rough weather in the number of faults that develop when heavy .downpours of rain occur, or when humidity is considerable, Aa to when the improvements, including tho equipment of the new automatic telephone exchange, will be completed, Mr Shrimpton remarked (as reported in "The Press" of December 17th last) that "it everything goes woll, and thero aro no more world wars, all the multi-office area in Christenurch should be cut into service within eighteen months from tho present." The progress beinjj made with the new work appears to indicate that Mr Shrimpton's expectations will be realised. At present the final portion of the underground work in St. Albans is being completed, and a start will be made shortly with the laying of the ducts in Colombo street southward from the Bank of Now Zoaland corner, through Sydenham to the Hills.