STATE HYDRO ELECTRIC SCHEME

Wairarapa Age, Volume XXXII, Issue 10624, 1 May 1912, Page 5

STATE HYDRO ELECTRIC SCHEME

The Auckland Star's correspondent telegraphed from Wellington that a further stage Li), the important work , of .oompleting the first of tho State hydro-electric schemes in New Zealand lias been reached, tenders being now out for tho transmission line standards from Lake Coleridge, aJid for the distribution wires' in Ohristehurch and districts It has been decided by the .Government Electrical Engineer to use ferro-concreto poles for the distributing mains,.and 500 are required to bo delivered at Ohristehurch. They are to bo.3sft' long. . . The transmission hue from tho power station is a much more expensive item, no fewer than 1400 standards being Required. Their material has been purposely left to the contractor to specify, the electrical engineer naming tho stresses! to bo borne. Delivery is to be at Lytteiton. The transmission line ltselr will also be supplied by tender, contractoi.. l>oing required to quote for aluminium as an alternative to copper. In tact, it is highly probable-tliat aluminium will be used for the main transmission from power house to city. This metal is not woll-luiown in New Zealand as an electrical conductor, hut it has been use.d in some of the largest transmission lines in Canada, and is often found in English installations. A copper line [is three and one-third times heaver 1 than an aluminium line of the same section. Aluminium being, however, only half as good an electrical conductor as its older rival, the alummuur line has to be of twice the section o. a copper one for the same .efficiency. Even then tho newer metal gains o msiderablv in tho matter of the weigh which has to be carried by the ( standards, while as its cost is about t j same as copper, and it is bough weight, here again aluminium scoies. It is estimated that an I line will affect a saving ot 30 per cent, so that the bin ovation will >e w 0 while. -