Hirschbergen tunnel
| Hirschbergen tunnel | ||||
|---|---|---|---|---|
 Entry portal from 1887
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| use | rafting | |||
| traffic connection | Schwarzenbergscher Schwemmkanal | |||
| place | Jelení , Bohemian Forest | |||
| length | 389 m | |||
| Number of tubes | 1 | |||
| construction | ||||
| Client | Joseph II Prince of Schwarzenberg | |||
| start of building | 1821 | |||
| completion | 1822 | |||
| planner | Joseph Rosenauer (†) | |||
| business | ||||
| closure | 1961 | |||
| location | ||||
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| Coordinates | ||||
| Entry portal | 48 ° 49 ′ 8 " N , 13 ° 52 ′ 24" E | |||
| Exit portal in Jelení | 48 ° 48 '59 " N , 13 ° 52' 39" E | |||
Map with all coordinates: The Hirschbergen Tunnel , also Schwarzenbergsch Schwemmkanaltunnel (Czech Tunel Schwarzenberského kanálu ) is a former water tunnel of the Schwarzenbergschen Schwemmkanal in the Bohemian Forest , Czech Republic . The building, unique in the Czech Republic, is protected as a technical monument and is located in the area of the Nová Pec municipality .
geography
The tunnel is located north of the village of Jelení and cuts through the saddle between the mountains Plešivec ( Raftberg , 977 m nm) and Jelenská hora ( Hirschberg , 1068 m nm).
history
The Hirschbergen Tunnel was built from 1821 to 1822 as part of the expansion of the Schwarzenberg alluvial canal as part of the New Canal between the Lichtwasser and the Hirschbachriese. The plans for this came from the builder of the canal, Joseph Rosenauer, who died in 1804 . The construction was carried out under the direction of the director of the Princely Schwarzenbergs, Ernest Mayer, by the engineers Falta and Kraus. In 1822 the tunnel through the 221 fathoms long tunnel with a width of 2.6 meters and a height of 3.2 meters was completed. In the following year, the tunnel received two brick portals. From the outlet portal, the water with the driftwood fell on a 286.6 m long giant with a gradient of 90.9 ‰ in Jelení, then Hirschbergen, into the Old Canal.
After the need for firewood decreased in the second half of the 19th century due to the increasing use of coal, the Bohemian part of the canal was rebuilt for rafting logs. In addition, in 1887 the strongly curved tunnel section after the entrance portal was replaced by a cut into the terrain with a smaller radius of curvature and the tunnel entrance was set back by 30 meters. A new portal with neo-Gothic decorative elements was created at the new entrance.
With the establishment of the Iron Process and the border fortifications of Czechoslovakia during the Cold War , the structure was in the border zone, with the exception of the period between 1965 and 1974 it was not open to the public. The Czech part of the alluvial canal between the Světlá and the Vltava near Želnava was still in use until 1961.
In December 1965 185 pug bats were counted in the tunnel . In the following years the tunnel partially collapsed. In 1980 the lower tunnel portal was renovated. On the occasion of the 200th anniversary of the start of construction on the canal, the Hirschbergen Tunnel was restored in 1989–1991. To protect the bats in the national park and for safety reasons, the tunnel is only accessible in short sections at the portals.
description
A curved, deep cut into the terrain, which was originally part of the tunnel, leads to the star entrance portal, which is decorated with two corner turrets, five battlements, two key notches and a pointed arch. During the restoration, the portal was returned to its original condition from 1887. When the portal was repaired earlier, the number of battlements had been reduced to three before 1930.
The stairway leading to the left of the upper section, about 1.25 meters wide, mostly walled-in flume, is a maximum of one meter wide. The ridge height is two meters here. After eight meters, the tunnel is blocked with a steel mesh gate. The tunnel is lined with granite for the first 25 meters.
The weather shaft II is located 100.8 m below the entrance portal. It is eight fathoms deep and secured by grating during the day. The name "Falta" is carved into a stone at the transition from the tunnel roof to the shaft. 100 meters below the shaft, a granite block with the year "1877" is placed in the tunnel wall.
The weather shaft I, which is also covered with a grate, is 172.8 meters below the weather shaft II ; it consists of three concrete walls and one wall made of granite blocks. Its depth is seven fathoms.
The following tunnel section, again lined with granite, is 2.2 meters wide and has a ridge height of approx. Two and a half meters above the cover of the 0.90 meter deep flood channel.
The outlet portal is located 122.8 m below the weather shaft I at 895 m nm. It bears the year "1823". Behind the portal is a carved Schwarzenberg coat of arms with a princely crown and the initials JA ( Johann Adolf ) and the year 1838. The tunnel is blocked by an iron grille 14 meters above the portal.
The tunnel has a length of 389 meters. A follow-up measurement carried out by Austrian cave researchers in 1991, however, showed a length of 396.4 meters. The difference in height between the inlet and outlet is 6.68 m, so there is a gradient of 16 ‰ in the tunnel. Next to the flood channel, which is now almost dry, a stairway leads through the tunnel.
literature
- Erhard Fritsch: The Schwarzenberg Alluvial Canal through the ages . In: Mitteilungen des Landesverein für Höhlenkunde in Oberösterreich 1993/1, serial no. 98, 39th year, pp. 43–74 online (PDF) .