ELECTRIC POWER

Poverty Bay Herald, Volume LXVI, Issue 19883, 9 March 1939, Page 5

ELECTRIC POWER

ARTHUR’S PASS LINE

REMARKABLE FEAT

(Special to the Herald.) WELLINGTON, this day. The completion of the 66,000 volt transmission line from Lake Coleridge hydro-electric generating station to the West Coast, over Arthur s Pass, is announced by the Hon. HSemple, Minister of Public Works, who states that testing is now being done.

As this important engineering work has been carried out in remote areas, mostly high mountain country, little has been heard of its progress, and of the spectacular nature of the enterprise.

The line erection gangs must have possessed high qualifications as mountaineers, the proof of this being evident in the Otira Gorge, where the steel towers of the transmission line seem to be often situated on inaccessible rocks, high above the roadway. These towers are 70 to 80ft. high, and they were easier to erect than wooden poles, as the steelwork could be hauled up to the site in sections, and bolted together. Natural Beauty Undiminished

Though designed to withstand the terrific mountain gales, the towers are not. clumsy in appearance, and the wonderful natural beauty of the Otira Gorge has not in any way been diminished by the construction of the power line. On the contrary, the work of man, wonderful a§ it is, provides just a puny contrast to the work of Nature on the grand scale, though the traveller will wonder how the obstacles have been overcome by the engineers and construction gangs. There is already a substantial load for Lake Coleridge electric power transmitted to the West Coast, owing to the development of gold dredging, and the new line will carry up to 21,000 kilowatts. The line, which seems to run at giddy heights over the Pass, consists of eight wires in all, carried on well braced steel cross-arms separating the wires by about 10ft. The highest pair are lightning conductors to protect the transmission lines from heavy -electrical storms frequently experienced in this high country. Two other groups of three wires each are the power conductors, each of seven-stranded copper wires. Strongly Built Towers

The steel towers arc spaced about six to the mile, and as the conductors will stand a breaking strain of nearly three tons, there are no anxieties regarding the results of high winds in the Pass, nor of a load of snow.

It will be a matter of interesting speculation to future travellers over the Otira as to how the construction gangs managed to get material for the steel towers to the tops of almost unclimable ridges. They developed rock-climbing skill, and the first man in the gang to reach the summit carried a light rope, which was used to haul up a heavier line. Often it was necessary to blast out a platform on which to work. Once a black and tackle could be rigged, tractors on the nearest point of the road provided haulage power for the heavy material.