Münden Tunnel

The Mündener Tunnel is a railway tunnel in the high-speed line Hannover -Würzburg at Hann. Munden, in the section between Göttingen and Kassel- Wilhelm height. With 10,525 m ( 120.99 to 131.50 kilometer ) in length, it is the second longest in-service railway tunnel in Germany (after the ridge tunnel ) and by far the longest tunnel in Lower Saxony.

Geographical location

The tunnel is located in the southern Lower Saxony Mündener Göttingen district. In the north- western part of the Kaufunger Forest, on which the southern part of the Natural Park Munden spreads, it is located between the Weser- source rivers Fulda and Werra in the west to the east. The tunnel is below the State Forest and State Forest Munden Kattenbühl and the wooded area south of the town of Hann. Munden and applied in the neighboring community Staufenberg.

The trains running on the high-speed line from the direction of Göttingen trains arrive from the east out of the rough mountain tunnel, crossing about 700 meters further south-west parallel to the Federal Highway 7 on the Werra bridge Hedemünden the Werra and reach the East Portal of the Mündener tunnel.

From this portal, the tunnel leads in northeast-southwest direction through the point near the base Muhlenberg Muhlenberg spur ( about 280 m above sea level. NN ), after which it crosses twice the highway. Then he runs through the northern edge of the heath head ( 321.7 m above sea level. ), Where the narrow valley of the Fulda influx hiking Steinbach near the tunnel on the highway 496 ( French bridge, 205.4 meters above sea level. ) Focuses on the murder of stones; the memorial stones bear witness to a robbery and murder in the year 1614. During the tunnel in this stream valley immediately southeast passes beneath the highway, he crosses it briefly before passing through the northwestern flank of Lutter Berger height ( 355.1 m above sea level. NN ). Thereafter, the tunnel leads under the current flowing to the Fulda Red Sieggraben along and passes through the north-west flank of Ickelsberg (304 m above sea level. NN ).

Finally, the trains leave Mündener tunnel at West Portal to with integrated bridge to cross a 300 -meter-long embankment, the narrow valley of the Fulda influx Ickelsbach to immediately southwestward to disappear in the mill head tunnel. Immediately afterwards, they cross over to the Fulda valley bridge Kragenhof the Fulda in Kassel -Wilhelm height.

Tunnel Description

The Mündener tunnel consists of a tube with two tracks. He owns approximately in the middle of the valley of the traveling Steinbach ( kilometer 127) an emergency exit (51 ° 23 ' 18 "N, 9 ° 37' 50 " O51.3883333333339.6305555555556 ) over a 15 m high stairwell. The tunnel can be driven with a maximum of 250 km / h. Inside there are approximately in the third points the crossovers " Kattenbühl " and " Lutterberg ". The mountain coverage is up to 175 m.

The route runs south-west first in a right turn, which turns into a left turn. At the transition to the southwest building section (Km 128), it recommends a straight course. The gradient decreases in the northeast area with 2,391 parts per thousand and flattens in the central and southwestern part of the section on a slope of 1.502 per thousand from. In the Southwest section of the route runs straight through, the gradient with 1.052 per thousand drops to the southwest portal back.

Geology

The Mündener tunnel passes under various formations of red sandstone. In addition to bank- ingen thick sandstones in the Solling and Detfurth result also dünnbankige, partly foliated, rocks occur.

History

Planning

Originally, the route should run in the region of today's Mündener tunnel in two tunnels that would have been connected by a viaduct. In the Northeast should be given to 5,580 m long tunnel Mündener State Forest, are driven in the southwest of 4,440 m long tunnel Lutterberg. In between the 125 m long, four -span viaduct Wandersteinbachtal should be built. The gradient would thereby increased in the northeastern tube to the southwest by 38 meters to the Wandersteinbachtal, and then drops in the southwestern tube about 58 m to the Fulda valley bridge.

The bridge, which would have been in one of Germany's oldest nature reserves, was discarded as part of the plan agreement with the City Munden and the District of Göttingen, Lower Saxony after the country had previously required to minimize the impact on nature and landscape in regional planning decision. Also a shorter, three -span bridge was rejected, and later an earth dam with three passages. Finally, the height profile of the line was lowered in this area by 30 m and under crosses the valley of the migrant Steinbach, which is crossed by the B 496 in a created cover tunnel section. The two tubes fused thereby a. Disadvantages of this solution were among other difficult access for maintenance and construction, and the necessary excavation of a 20 to 40 m deep excavation in the close quarters of the Steinbachtals.

Another difficulty arose loud train information, the demand of the planning approval, the water supply of the city Munden, was their water extraction in the area of the main access point, had to be revised before construction begins. Thus, the tunnel to the critical element in the commissioning of the section between Hanover and Kassel had become.

Award

Because of its great length of the tunnel was divided into two sections and awarded to two different contractors: The section north makes with 7,980 m length (km 121.0 to 129.0 ) from the bulk of the tube, which is south-west with 2,545 m (km 129.0 to 131.5 ) shorter, but includes the southwestern subsequent mill head with a tunnel.

To stop the tube, in October 1983, the planned length was still at 10,400 m.

Construction

The construction of the tunnel Mündener took place between July 1983 and July 1989.

They started in July 1983 at the southwest portal. With the tunnel stop on the West portal in Ickelsbachtal and the adjacent mill head tunnel, the construction works were officially launched in the section between Kassel and Göttingen on 27 October 1983. About 1,000 spectators were present at the ceremony, in which the two godmothers tunnel together with a button triggered the first blast. Among the guests was one of Ernst Albrecht, the then Prime Minister of Lower Saxony. The sponsorship had his wife, Heather Adele Albrecht taken.

For the propulsion of the Werra a drill and blast excavation was provided. The inner shell should be backed up to October 1986 78,000 m³ shotcrete and 50,000 m³ of reinforced concrete (as of 1983). About 700,000 m³ outbreak and excavated material had been expected, which should be deposited in a landfill and a railway embankment.

For the four ventilation shafts were abgetäuft 94-130 m depth.

For the 7.98 km long main thrust of 1.7 million cubic meters were moving excavated material, 12,000 tons of reinforcing steel, 200,000 m³ shotcrete and 270,000 m³ situ concrete installed. At the intermediate heading the excavation material of trucks over a serpentine driveway were worn. A total of 1.2 million cubic meters of excavated material were deposited at 2.5 km from the top of the Steinbachtals. The spruce forest lying there previously was thereby converted to an area of ​​21 acres in a wetland. The previously almost level terrain was thereby increased by up to 20 m.

Approximately in the middle of the tunnel ( at km 126.7 ) established a intermediate point of attack in the area of ​​Wandersteinbachtals, from which in a northeasterly and southwesterly direction was drilled. In the intermediate section applied in an open design for a permanent opportunity remained to the tunnel. Since the gradient of the line was in the range of between attack only a few feet below the bed of the migrant Steinbach, this is temporarily out of 250 m length in a penstock of two meters in diameter around the excavation around.

As of April 1985, moreover, sometimes down to 500 m in length, from the Werra a counter- thrust.

As was the tunneling from three places, the two portals and the central portion, be made. The final breakdown was celebrated on October 6, 1988. It was also the last tunnel breakdown of the 61 tunnels of the high-speed line. On November 2, 1989 the symbolic welding of the last track in the section Göttingen- Kassel, the so-called gap-closure, in Mündener tunnel. A 60 m long section of track has been used by six track-laying machines, the. Representatives of Lower Saxony, of the district of Göttingen, the city of Hann Munden and the Federal Railroad were served at the same time. Previously, the tunnel construction of tunnel patron Albrecht had been officially terminated.

In the northern section fell to 990,000 m³ tunnel excavation, for the pre-cuts 125,000 m³ of material was removed. 205,000 m³ of concrete and 9,600 tons of steel were used. The Contract price (as of 1987) for this lot was 160 million marks. Entrusted with the construction companies were Dyckerhoff & Widmann AG (Frankfurt am Main) and Bilfinger Berger AG (Hannover).

In the Southwest section - including the mill head Tunnels - fell to 520,000 m³ tunnel excavated material and 220,000 m³ from the Voreinschnitten. A total of 135,000 cubic meters of concrete and 4,400 tons of steel were used. The planned construction cost was originally estimated at 120 million D-Mark. The excavated material was partly spent on the construction of dams and landfilling. The remaining overburden was heaped on the nearby highlands of the Kaufunger Forest; the thus formed knoll called chicken Feldberg.

With the construction of the southern lot, including the mill head tunnel, the company E. Heitkamp GmbH ( Herne ), rock and Civil Engineering GmbH ( Recklinghausen) and Sachtleben were commissioned Mining GmbH ( Lenne city).

As ecological compensation measures for the construction of Mündener and the adjacent mill head tunnel was placed above the new line a wetland of about half a hectare of land. Additional funded the Federal Railroad at the request of the district of Göttingen a new wetland in the district Staufenberger Nienhagen as an alternative measure. Several conservation organizations were challenged to build a bridge in place of the dam in Ickelsbachtal.

Completion and commissioning

The building was the end of July 1989 structurally complete. On 29 May 1991 the tunnel was Mündener taken together with the new lines section Hanover - Fulda in operation. The tunnel construction costs amounted to around 200 million DM