TUNNELS OF THE WORLD.

Evening Post, Volume XXXVI, Issue 102, 27 October 1888, Page 1 (Supplement)

TUNNELS OF THE WORLD.

Every writer who ha 9 given any Btudy- to the railway system of Great Britain, as compared with those of other countries, has observed the great solidity and strength of its iron roads. The late Henry Ward Beecher wrote. "The bridges, stations, viaducts, track, and all parts of the road are seemingly built for eternity." Doubtless when he paid us that high compliment he had in his mind the flimsy way in which American railroads are too often built. In no particular is this stability more noticeable than in the tunnels, which in nearly every case are of the very highest order of construction. There are no less than 95 miles of tunnels, built at and average cost of £50 per yard, but ranging from £20 to as much as £200. The longest tunnel in Great Britain is the Severn ; it is four-and-a-half miles in length, and was constructed at a cost of nearly £2,000,000 in thirteen-and-a-half years. It may be mentioned that no less than 75,000,000 bricks were used in its lining. Another important tunnel is the Woodhead, on the Manchester, Sheffield, and Lincolnshire Railway. It is 5297 yards in length, and took six years in construction, during which time the pumps at work pumped out over 8,000,000 tons of water. The celebrated Box Tunnel, between Bath and London, is nearly two miles long, and in its construction over 414,000 cubic yards of earth were excavated. A very expensive tunnel was the Kilsby, on the London and North Western Railway. Though only 2,423 yards long, in consequence of the- hard nature of the rock' the cost) of construction was something like £120 per yard. The expense qf goring through rock, in spito of all our improved apparatus, is so great that it tfaally seems a pity we cannot adopt the expedient wliich the mendacious Livy describes Hannibal as having used in his passage over the Alps — namely, heating the rock, and then instantly causing it to melt by pouring vinegar upon it. Enormous, however, as these figures are, they are, comparatively speaking, small if we consider the fabulous amounts expended in making the Metropolitan and the District Underground Railway.

That system, aajs the Railway Press, is' about twenty miles long, and its cost was so great that we can get an idea of it much better by calculating by the inch, not by the yard. The average cost per inch was over £5, and the Inner Circle cost half a million a mile, which figures out to nearly £8 per inch. Not much wonder, if we consider these facts, that the company have not found it a Bonanza, for what tremendous profits must be made to pay interest on the immense amount of capital sunk in the undertaking ! The greatest difficulties which had to be faced by the underground railways had to do with the sewage and gas mains, all of which had to be diverted at great cost from their original courses. It would hav.e been cheaper and better to have sunk deep shafts, as those difficulties could then have been avoided, and it would have been easy to have arranged for the passengers to go up and down in lifts. The Elevated Railway in New York, which answers every purpose for which our underground lines are I used, was erected at less cost, and gives its passengers the inestimable advantage of fresh air. We are quite unable to appreciate the triumphs of engineering skill exhibited by our tunnels when we are being half choked with the noxious fumes which exist under the present defective system of ventilation. One of the longest tunnels in the world is the one at Schainnitz, Hungary. It has a length of 1 0-27 miles — one mile longer than the St. Gothard and two-and-a-half miles more than the Mont Oenis tunnel. When the contract was made in 1872 the work was let at about 3 sdols. a yard, but for some years before its finish, some time ago, the cost was about 110 dols. per yard. We ought not to omit to mention the two great Continental tunnels — the St. Gothard and the Mont Cenis — the former of which occupied fourteen years in completion, and may juslly be described as one of the mostremarkable engineering achievements of the century. We give, in the following table, the lengths of the ten longest tunnels in England — , Yards in length. Sovern Great Western 7664 Stanbridge Nortli Western 5342 Woodhead Manchester & Shef- 5297 field Bramhope North Eastern 3745 Medway South Eastern 3740 Sevenoaks South Eastern . 3500 Box Great Western 3227 Littleborough Lancashire & York- 2869 shiro Sapperton Great Western '2800 Polchill South Eastern 27-59