Zugspitze tunnel
The Zugspitze Tunnel is a 4466 m long railway tunnel of the Bavarian Zugspitzbahn . It leads from the Riffelriss stop to the former Hotel Schneefernerhaus below the Zugspitze summit and overcomes an altitude difference of 1010 m. The gradient of the rack and pinion track in the tunnel is 25%. The tunnel was opened to traffic on July 8, 1930 after a construction period of only 19 months. Since 1988, most of the traffic has been handled via a new terminus on the Zugspitzplatt .
Planning and construction
Surveying and route planning
On July 14, 1928, the contract to build the tunnel was awarded to a consortium led by AEG . Immediately afterwards, the preparatory work for the tunnel construction began.
An important prerequisite for the start of construction was an exact measurement of the Zugspitze massif. Since it was not possible to measure with conventional means in the difficult-to-access high alpine terrain, the new maps were created using stereo photos and with the aid of some fixed landmarks in the valley and on the neighboring mountain peaks.
The air line between the lower tunnel portal at Riffelriss and the tunnel station at Schneefernerhaus is just two kilometers, albeit with an altitude difference of 1010 meters. Since an incline of 25% could not be exceeded for safe operation of the cog railway , the result was a tunnel length of at least four kilometers, which had to be led in a wide loop through the mountain.
The tunnel was to be driven through the mountain with the help of blasts and jackhammers. At the time, this technology could drive four to six meters per day. In order to complete the tunnel in the allotted time by the summer of 1930, driving had to be started at several points at the same time. Since the start of construction from the Zugspitzplatt was ruled out because of its poor accessibility, the winding tunnel course was laid in such a way that it came right up to the north face of the mountains in three places. There short access tunnels, the so-called tunnel windows, were driven into rock from the outside to the future tunnel section. Thus, together with the tunnel portal on the corrugated crack, construction could begin in four places.
Construction site equipment
Immediately at the lower mouth of the tunnel on the Riffelriss, an extensive construction warehouse was set up which, in addition to workshops, warehouses and a concrete plant, also housed accommodation and a canteen for up to 800 workers. Smaller construction stores were also set up on the initially three tunnel windows. At the highest window, caverns had to be blasted into the rock along the access tunnel, as the steep rock wall made it impossible to build above ground.
The only practicable way to transport materials to the construction site was to use auxiliary cable cars . Between 1928 and 1930, a total of six of these systems were built, which were used not only to transport materials but also to transport people:
- Eibsee - ripple crack
- Corrugated crack - window 1
- Corrugated crack - window 3
- Corrugated crack - window 4
- Window 4 - eastern Zugspitze summit
- eastern Zugspitze summit - Zugspitzplatt
After completion of the tunnel and the actual summit cable car, the auxiliary cable cars were dismantled again.
Construction and completion
Work began on the lower mouth of the tunnel in October 1928 and on the tunnel windows in the following months. The construction was delayed by loose rock at the mouth of the tunnel on the corrugated crack, which is why a fourth tunnel window was added in May 1929 to speed up construction. The construction went without significant difficulties, so that on January 15, 1930 all tunnel sections were connected with each other. Finally, on February 5, 1930, the break through to the Schneeferner came . In the weeks that followed, the tunnel had to be expanded and lined up before the tracks and overhead lines could be installed. On June 20, 1930 the first construction train reached the railway station at Schneefernerhaus, and on July 8 of the same year the line from Eibsee was opened for passenger traffic.
safety
There are six fire protection caverns along the entire length of the tunnel, which serve as escape rooms for train passengers in the event of a fire and are equipped with telephones and lamps. At the tunnel portals and about halfway through the tunnel there are gates that are normally closed and only open when a train approaches. In the event of a fire in the tunnel, this should prevent the dangerous chimney effect .
The Rosi tunnel
The route of the tunnel to the Schneefernerhaus has increasingly proven to be an obstacle for ski tourism, as you first had to change to the cable car to reach the ski areas on the Zugspitzplatt . It was therefore decided to build a 975 meter long tunnel branch to the Zugspitzplatt and to build a new train station at the Sonnalpin restaurant there.
The construction of the tunnel was very costly. First of all, a 20-meter-long tunnel was driven through the rock from the railway station at the Schneefernerhaus. In this way, all construction machinery delivered there by cog railway and all the material from the platform were transported outside and transported down the slope with a cable winch. Construction work on the Zugspitzplatt began on June 14, 1985 with the first symbolic demolition, initiated by the skier Rosi Mittermaier-Neureuther , who gave the tunnel her name as godmother. As with the construction of the main tunnel 56 years earlier, the new section was also blasted through the rock. The workers had difficulties with multiple water ingress and loose moraine debris. The breakthrough to the existing tunnel was finally achieved on December 9, 1985. After completion of the track system, the first construction train reached the Zugspitzplatt on June 19, 1986, and the station has been approaching as scheduled since January 15, 1988. On January 14, 1992, the Schneefernerhaus was closed to the public and subsequently converted into a research station. This also ended the regular train journeys there, since then only material has been transported.
Stopping points and operating points in the tunnel
Stopping point tunnel window
(Tunnel kilometer 0.8; 1820 meters in altitude) Before the window 1 (km 1.1) set up for the construction of the tunnel is reached, the former “Tunnel window” stop is located. For a few years, skiers had the opportunity to get off there and use the ski run into the valley from there. However, this was limited to a few days a year when snow and weather conditions allowed a descent.
Dodge 4
(Tunnel kilometer 2.0; 2115 meters in altitude) In order to achieve as close a train sequence as possible on the single-track route, several diversions were necessary, one of which is in the tunnel. In this area the tunnel runs at a lower incline. This was made necessary by the rack and pinion system used in the points and differing from the rest of the route.
Höllental stop
(Tunnel kilometers 2.9) Originally it was planned to lead a 200 meter long pedestrian tunnel from this point into Höllental . A two meter wide platform was already built when the railway was built, but it never went into operation.
Junction point Tu
(Tunnel kilometers 3.9 / 0.0) With the construction of the Rosi Tunnel, the branch was added later. Here the slope of the track has been reduced from 25 to 23 percent. Nevertheless, a special switch had to be constructed with a continuous rack in the Riggenbach system that was also used on the route. The conventional switches were unsuitable for this gradient.
Schneeernerhaus station
(Tunnel kilometer 4.4; 2650 meters in altitude) The station has two stub tracks, each with a 2.5 meter wide platform, which are located in separate tunnels behind the Schneeernerhaus in the rock.
Zugspitzplatt train station
(Tunnel kilometer 0.9; 2588 meters in altitude) The above-ground train station is directly adjacent to the end of the Rosi tunnel and the Sonnalpin restaurant. It has two tracks with one middle and two outside platforms, which are designed for large crowds. One track has a loading crane for loading and unloading freight wagons. The station was provided with a barrel-shaped corrugated iron roof, which was covered with stones and rubble for optical reasons.
Individual evidence
- ↑ a b c AEG-Mitteilungen: Die Bayerische Zugspitzbahn , No. 4, pages 205–295, Berlin 1931
- ↑ Death trap Tunnel in Focus , No. 47/2000
- ↑ a b Festschrift for the opening of the Rosi tunnel and glacier station on the Zugspitzplatt , January 15, 1988 (excerpt)
- ^ A. Weber: Construction of the Garmisch – Schneefernerhaus line. In: AEG communications. Issue 4/1931, pp. 218-232.
Web links
Coordinates: 47 ° 26 ′ 2.4 ″ N , 10 ° 59 ′ 10.8 ″ E