Victoria tunnel
The Viktoria-Tunnel (alternative spelling Viktoriatunnel ) is a 28-meter-long spur tunnel on the Lötschberg southern ramp between the Ausserberg and Lalden stations . It is also the shortest tunnel on the Lötschberg mountain route .
Names
The tunnel is named after the English king Victoria . The rock spur that is broken through with the tunnel, seen from the Baltschiedertal, is very similar to the profile of the Queen, which was also seen on the English postage stamps. That is why the rock spur was given the name Viktoriakopf by the engineers commissioned to build the railway.
History and geology
The stone block that forms the Viktoriakopf comes from an old landslide and supports a whole ridge of large, stacked boulders. The geological observation solidified when the service railway tunnel was driven through this spur. Originally it was planned to blow up part of the block, but there were fears that the debris released by the blasting could have dammed the Baltscheiderbach, which would have threatened the village of Baltschieder . Blasting the block could also have made the entire slope unstable, which is why the Valais government refused to blast it. So it was decided in 1909 to create an exploratory shaft at the foot of the head for geological investigation. The service railway tunnel cut the stone block on the rear side, which is why the width of 16 meters was known. The exploratory shaft revealed that the boulder had to be at least 26 meters high. The geologists attested that the boulder had sufficient stability for a tunnel. As a result, the BLS decided to build a 21 meter long tunnel at this point. However, also as a result of the collapse on October 10, 1912, the tunnel was ultimately lengthened by seven meters in the direction of Goppenstein. This means that the length will be 28 meters upon completion. It was one of the few tunnels that was completely excavated in the double-lane profile from the start.
The construction of the second track in this section did not begin until 1986 and the double lane through the Victoria Tunnel was put into operation on November 23, 1990.
construction
The western tunnel mouth (side Frutigen) is at construction kilometer 49.098, today's route kilometer 63.557, the eastern tunnel mouth (side Brig) at construction kilometer 49.117, today's route kilometer 63.585. Despite the planned length of only 21 meters, the tunnel was considered to be the heaviest tunnel to be built on the entire southern ramp from the start. In addition to the geological problems, it was one of the few tunnels that should run along the route of the construction railway. So it had to be built in such a way that the operation of the construction line was affected as little as possible.
Construction began on the Brig side, using the Belgian method but with sole tunnels. The service railway tunnel was used as the sole tunnel, but its axis did not coincide with the axis of the final tunnel. In addition, the company had to be able to continue to operate. This led to rather complicated and not exactly optimal carpentry conditions for the brick lining. The thickness of the walling of the ceiling vault and the abutment (on the transom) is one meter and is in the profile form of type C 6 , with the ceiling vault being 1.2 meters thick in the area of the west portal.
The collapse
In the morning of September 20, 1912, the tunnel was examined by the technical director and technical advisor for this section. It was decided to extend the tunnel by seven meters so that the seven-meter lining wall at the west portal could be dispensed with. At the same time, the lining wall was bricked up to within seven meters of the originally planned portal. It turned out, however, that this lining wall would be more and more difficult to build because of the landslide material. The cut had already broken out and supported with wooden beams. At this point the callotene excavation for the Frutigen side vault was completed and the next day the plan was to start building the remaining six meters on the next day, for which the last steps were carried out on the iron teaching arch. The first 15 meters of the vaulted ceiling on the Brig side were already bricked. At half past four in the afternoon, a small mass of rock loosened from the head notch and carried away parts of the overlay of the portal ring. Unfortunately, at the time, the engineer Lemarchand was busy recording the extension of the seven-meter piece that had been decided that morning. Although he tried to escape into the tunnel, but was it detected by the collapse of the tunnel installation, as well as the workers Guerini , who was there, the falsework to get engaged ash. Both people were buried and could not be recovered until the night of October 18-19. The injuries found suggested that they had been killed on the spot. The collapse only affected the non-lined part of the tunnel, the already lined areas remained undamaged. The triggered by the collapse cubage is indicated with m³ 600th Railway operations were resumed on October 29th.
literature
- Claude Jeanmaire: Lötschbergbahn under construction. Archive No. 58, Verlag Eisenbahn, Villigen 1989, ISBN 3-85649-058-2 . In the text, pages 109, 129–130. In the picture section 1380–1404
- Report on the "collapse of a tunnel" on the southern ramp of the Lötschbergbahn. published in the Schweizerische Bauzeitung , volume LX, page 245 (issue 18, issue November 2, 1912) digitized on E-Periodica.ch