Engineering Wonders of the World
Volume III

CONSTRUCTION OF BERGEN-KRISTIANIA RAILWAY. 355 The Gravehals Tunnel. water-power each end to Italian Miners imported. of men were not allowed to bring their families into the mountains. But by way of com- pensation the wages were high ; and as few opportunities of spending money occurred, those men who kept to the mountain work for several years were able to amass a very considerable sum. The Gravehals tunnel is notable not only on account of its great length—17,421 feet—but because its construction was attended by the great difficulties caused by the great distance from a base of supplies, and by the fact that the workmen were entirely isolated during several months of the year. In fact, this may be considered one of the most arduous pieces of tunnelling ever accom- plished, and worthy to rank beside the far longer Alpine tunnels which formed the subject of a previous article. Excavation was begun in 1895, after a station had been erected at drive the pneumatic and hy- draulic drills used in the Myrdal and Opset headings respectively. As the con- tractors could not obtain a native workmen accustomed to machine drilling, they imported, in 1900, fifty Italian miners who were experienced in this kind of work. Unfortunately, the rock en- countered was so much harder than that previously mined by the Italians that events proved one Norwegian to be worth two southerners So when the Norwegians had learned the technique of the drills thoroughly the foreigners were packed off home again. During the winter 1902-3 the tunnellers at the eastern end had a very bad time. For two and a half months all communication with the outside world was cut Hard Times. „ , on. Stores gave out, and coal and wood had to be doled out in meagre rations. Things looked so bad that there was serious thought of abandoning the work for the season and beating a retreat. But luckily, before such a course became necessary, the headings met, and bread was brought through from Opset. On some of the stormiest days of this winter the wind velocity exceeded the maxi- mum which the anemometer could record— 90 miles an hour. One of the houses in which the men lived Snow i j , n Blockades. was completely covered up— all but the chimney—by the snow, and could be reached only through a snow tunnal af considerable length. This tunnel was often blocked during the night by a snowstorm. Consequently, when the night-shift came off duty they had to shout down the chimney, and obtain the assistance of those inside to dig a way through. In such circumstances it is not strange that the men should have found their work unattractive. Even when travel was possible it was not free from danger. The way could easily be lost at night or during a snowstorm. The telephone line, if struck, could be made to serve as a guide by throwing a piece of string over the wire and drawing it along to the next post, where it had to be released and flung over the succeed- ing span. On one occasion a paymaster and his guide were lost in a storm and frozen to death. In spite of all obstacles the tunnel was completed, after twelve years of incessant labour, in 1906. The rock blasting consumed 495,000 lbs. of dynamite and 310 miles of fuse, and required the drilling of 350,000 holes, with an aggregate depth, of further million pounds of dynamite were ex- pended on the other numerous tunnels and on the cuttings, from which about 2,400,000 cubic yards of rock and earth were removed. The track is of standard gauge (4 feet 8J inches) throughout, the original narrow gauge track between Voss and Bergen having been changed to standard during the years The Tunnel completed. 217 miles. A