Tunnelling the Alps.

New Zealand Graphic, Volume XLII, Issue 3, 20 January 1909, Page 15

Tunnelling the Alps.

A lot uf interesting informal ion « contributed to “( hainber>* .huirnar’ for October by Mr. H. (.’. \r<her on the railway constructed or proje» t<*<| through the Alps. Tin* following, are great Alpine tunnel-* at present « on'truvted: —- Mont Onis (1857 70), 7 miles 1.73<1 yards; St. Gbtthard (!B72xdi. 9 miles 46!) yar<!<-, Arll)erg ( 1878 M.’D. 6 mileg 550 yard-; Alim la (1899 l!M)3), 3 miles 1,150 yards; Simplon ( I8!»8 1905) 12 mih*s 537 yard-*. It will be obvious that a high level tunnel through the immense barriers formed by the \lpin<* rangesentails long am! steeply-graded accents to its portals. 'l'he Mont (’eni< funnel has a maximum altitude of 4,248 feet above sea-level, 'i'he highest point reached by the St. Gothard tunnel is 3.787 feet. The Arlberg line has elimbed up to an altitude of 4,300 feet by the time the centre of the tunnel is reached, and its approaches are almost ar- steep as those on the Si. Gotthard. But while the Simplon tunnel is the least steeply graded, and therefore the most oi-onnmi* al to operate, of any transalpine railway so far constructed, the tunnel it<e)f achieves a fresh record in respect of depth, rhe depth of itt* axes beneath the surface averages 3,740 feet, and where the frontier betwei'n Switzerland and Italy is, crossed attains the phenonnnal depth of. 7,000 feet. The deepest point in the St. Gotthard tunnel is 6.07(» feet, in the Mont Cenis 4.000 feet, ami in the Arlberg 1,600 feet. The cost.of the Simplon tunnel (says Mr. Archer)) as at presen; eunst ructed, wad During the short lime that has elapsed since it was opened such an enormous stream of trallir has flowed along the new route that it has been decided at once to proceed with the duplication of the line by enlarging the auxiliary tunnel to its full dimensions, which task will occupy about three years and coi-:t another L* 1,600.000. and also with shortening the approaches from the north. • What is known as the Loefschberg railway, will be a fif’h great Alpine tunnel, pierring the Rer<ncs<« .\lp-. I'he object of the Loe* sch’lHTg line is to shorten the ;».pproaches to the Simplon from central Switzerland.,. Germ iny, ami north-western Europe generally. The south-bound traveller who enters the Continent at t'alairj qr Boulogne, will no. longer pass through Parish on the other hand, he will he borne through Berne, the capital of Switzerland. By this means the length of the direct journey between Calais ami Milan will be shortened from 725 mile’s to 6724 miles, while that bet.ween Paris and Milan will become 51 i miles instead of 523 miles in length. The great 'tunnel will pierco the Schafberg, a peak 8.444) feet in height, and pass underneath the Gastem valley am! the Loetschen Pass, emerging, at (Inppenstrin, in the lower part of the latter pass. The distance from portal to portal h- 8.53 miles, and the alignment uf the po.rforation is dead -thaight. At the summit of the perforation, which reaches an altitude of 4.000 feet above sea-level, there will be a perfectly long streicb, where, if necessity arises, trains can be shunted or transferred from one track to tin.* other. The total length of the lyoetsehborg railway from Frutigen to Baron will be 26J miles: and besides the great tunnel there will be thirtythree others, forming about 22 per eent, of the total length uf the lines of acees.4 to the former. 'The entire contract haq been let by a. syndicate of Parisian capitalists for the sum of €3,500,000 sterling, and the work must he completed a»hl ready for traffic by 1-t September. 191 I.