A THIRTY MILE RAILWAY TUNNEL.

Pukekohe & Waiuku Times, Volume 6, Issue 266, 13 April 1917, Page 2 (Supplement)

A THIRTY MILE RAILWAY TUNNEL.

Xot so very many years hare ] ed since the time when the prop to build a two track railway tu fUj miles in length beneath one of great mountain ranges of the w would have been thought prepos oils; but m these days of big ei eering achievement, the question mero physic-al magnitude is often least serious element of an under ing. During the development of great raidway systems of the w tiiero has been a marked inci in the cost and time of construct of the long tunnels which were cessary to carry the lines across various continental divides, most important of these tunnels least in respect of their length, to be found in Europe, more part larly in the Alpine regions, and following details as to their lei and the rate of progress in their structicn are illuminating. The of these, the Mont Cenis, built 1857-1871, is 7.5 miles r length, the rate of progress was 7.75 feet day. Then came the St. Goth 1872 to 1881, 9.5 miles in len in which the rate of progress ros 18 feet per day. The Arlberg nel, 6.5 miles in length, built in 1 to 1884, was put through at the of 27.25 feet per day. The Sim] tunnel, 1893 to 1899, 12.25 mile length, was built at the rate ol feet per day; and the Loetsch! tunnel, 1906 to 1911, 9 miles length, was built at the same of 36 feet per day. It is now proposed by Briga* General H. M. Chittenden, U.S.A. tired) to drive a two track tu: through thje Cascade Range of m< tains, which will be 30 miles length and have a summit e'.eva not much over 1000 feet above level, the object of this great * being to give a short and easy to Puget Sojund and the great ports of the north-west, and avoid serious interruptions and disast accidents which have occurred late years on the present high 1 railroads across the mountains. Regarding the cost and time construction, the writer bases estimates on the experience had i the double track Rogers Pass tui through the Selkirk range on Canadian Pacific Railway, which now nearing completion. Prog has been at the rate of about 52 per day, which it shoul be note* a striking advance on the rat« the Simp'.on and Loetschberg i nels through the Alps. To expe the work, four shafts, from 1, feet to 2,320 feet in depth, woul< sunk along the line of the tunnel, it is estimated that with these 1 shafts the 30 miles of tunnel c< be put through in five and a years at a total cost of 43,237, dollars. As to the operaing advanta the Great Northern Railway wc abandon its present railway over mountains, which has gradients high as 2.2 per cent, and takes tl hours for passenger trains and hours for freight trains to trave and in its place would have a m ly straight and level line, free fi risks, and with a passenger tim< forty minutes and a freight tim< an hour and a half. The North Pacific routo wouid be reduced miles in length and 1,850 feet vertical lift, while the average sa\ of distance for the Union Pa< would be 180 miles by one re and 140 miles by another.