Sea barrier Nas
Map with all coordinates: 
The Seesperre Nas was a military line of defense of the Swiss Army during World War II at the entrance to the Reduit . The closure of the narrow lake of Lake Lucerne between the rock noses of Ober Nas ( Vitznau , Canton Lucerne and Gersau , Canton Schwyz ) and Unter Nas ( Ennetbürgen , Canton Nidwalden ) is unique because it represents the defense of a stretch of coast in Switzerland. In addition to the road block, it included a floating sea obstacle and two coastal batteries (artillery works Ober Nas and Unter Nas). The nearby Mühlefluh artillery plant was not part of the lake barrier. From 1947, the Nas Seesperre was part of the Reduit Brigade 24 . With the reorganization of the fortifications (TO 51), the two artillery works became infantry works in 1962.
Strategic importance
The Vierwaldstättersee was a possible axis of incidence of the German operational planning, because it enabled access in the direction of the Gotthard . With the Rütli report of July 25, 1940, the 850 m wide Nas Narrow Sea played an important role in the army's defense system as an entrance gate to the central space position (reduit). It had to be fixed and held to the limit . The countless fortifications at the Reduite entrances, especially within sight of Lucerne (Artillery Works Mühlefluh, Ober- and Unter Nas, Fürigen , Kilchlidossen , Fortress Klein-Durren , Fortress Mueterschwanderberg (Zingel, Drachenfluh, Blattiberg), Fortress Wissiflue and Ursprung) were sometimes more extensive and more powerful than the big, well-known fortresses. They closed the bottle necks of the Reduite entrances between Rigi , Bürgenstock and Pilatus like a stopper.
The strategic importance was also shown by the fact that the German intelligence service concentrated its espionage activities particularly on the Reduit area in central Switzerland in preparation for the intended attack . The Rigilehne and the fortifications of the Nas Narrow Sea were not spared, which in one of the espionage cases meant the death sentence for one of the troops.
“ Our fortifications were one of the most sought-after objects of German espionage. There is no doubt that the German leadership was well informed of their progress. Some things may have been exaggerated by agents and traitors. The German leadership valued the fortifications for defense. (...) I am convinced that our fortresses played an important role in German plans from around 1943 onwards and it is likely that they played a key role in preventing an attack on Switzerland. The expenses for the fortifications have therefore paid off. "
Fortress construction
Until the mobilization of war on September 1, 1939, there were no fortifications or obstacles on the heights around Lake Lucerne and its shores, because in the run-up to the Second World War, the expansion of the defensive positions on the northern and southern borders and the fortresses St. Gotthard , St. Maurice and Sargans had priority. Chief of Staff Jakob Huber , as the former commander of the fortress St. Maurice, was the military expert in the army command for the fortifications to be built. The militia army was able to develop unique solutions in special cases such as the Nas lake barrier or the flooding of the Lin Plain thanks to the know-how of its specialists from various professions. On the basis of the operational order No. 12 of July 17, 1940 (reference to the central room position, Reduit), the commander of the 3rd Army Corps , Rudolf Miescher, issued the “Order for the organization of the implementation of fortifications in the central area” on August 16, 1940. In September 1940 Ober and Unter Nas were subordinated to the 3rd Army Corps for tactical reasons .
In 1940, the Lucerne Construction Office of the 2nd Army Corps began planning and building the Nas lake barrier. The Ober Nas, Unter Nas and Fürigen fortresses were designed by the construction office to match the size, armament and equipment. Construction of the three fortresses began in February 1941. Ober and Unter Nas were handed over to Fortress Guard Company 15 in March / April 1943.
Artillery Works Ober Nas (A 2215)
The Ober Nas plant was located at the tip of the Ober Nas headland on the border between the cantons of Lucerne and Schwyz near Vitznau. The work, which began in 1941, was expanded in 1943 as a base with ten shelters to protect a floating obstacle with which Lake Lucerne could be blocked between the Upper and Lower Nas.
Two road barricades protected by infantry work had to prevent a breakthrough on the right lakeshore road.
The armament consisted of a 7.5 cm attachment cannon 39, two 4.7 cm attachment anti-tank guns 41 and three machine guns 11. The notches were only a few meters above the lake. In 1941, a 55-meter-long underground funicular was built from the plant at 445 meters above sea level. M. to Kantonsstrasse 473 m above sea level. M. created.
The Ober Nas plant later served as a barracks for the motorboat detachments of the Swiss Army, which used the Vitznau lake basin for target practice. The finish area was the «Matt» quarry on the Bürgenstock.
- Infantry factory Obere Nase A 2215: Entrance 1 ⊙
- Infantry factory Obere Nase A 2215: Entrance 2 ⊙
- Infantry factory Obere Nase A 2215: Pak stand «Bruno» ⊙
- Infantry factory Obere Nase A 2215: Mg stand 1 «Max» ⊙
- Infantry factory Obere Nase A 2215: Mg stand 2 «Moritz» ⊙
- Infantry factory Obere Nase A 2215: Mg stand 1 «Max» ⊙
- Infantry factory Obere Nase A 2215: Mg stand 2 «Moritz» ⊙
- Infantry plant Obere Nase A 2215: MG stand 3 «Marta», 9 cm anti-tank gun stand «Berta» ⊙
- Infantry factory Obere Nase A 2215: 7.5 cm BK / headlight «Anna» ⊙
- Infantry factory Obere Nase A 2215: MG stand 4 «Minerva» ⊙
- Infantry factory Obere Nase A 2215: Mg stand 5 «Mercedes» ⊙
Lock point Ober Nas
- Infantry plant Kalibach A 2214: two Mg 11/51, bricked up in 1992 ⊙
- Team cavern Obernas – Linden 1, Vitznau A 2216 ⊙
- Team cavern Obernas – Linden 2, Vitznau A 2217 ⊙
- Team cavern Obernas – Linden 3, Vitznau A 2218 ⊙
- Team cavern Obernas – Linden 4, Vitznau A 2219 ⊙
- Cavern Obernas – Linden 5, Vitznau A 2220 ⊙
- Team cavern Obernas – Linden 1, Gersau SZ A 2221 ⊙
- Team cavern Obernas – Linden 2, Gersau A 2222 ⊙
- Team cavern Obernas – Linden 6, Gersau A 2223 ⊙
- Team cavern Obernas – Linden 7, Gersau A 2224 ⊙
- Team cavern Obernas – Linden, Gersau A 2225 ⊙
- Tank barricade Kalibach T 1304 ⊙
- Armored barricade upper nose T 1305 ⊙
Artillery Works Unter Nas (A 2226)
The plant was located on the eastern foothills of Unter Nas of the Bürgenstock in the area of the municipality of Ennetbürgen , canton of Nidwalden . The two-part plant (north, south) was best reached by sea.
The armament consisted of a 7.5 cm attachment cannon 39, a 4.7 cm attachment anti-tank cannon 41 and four machine guns 11. The artillery works Ober Nas and the counterworks Unter Nas had a crew of 60 men each.
- Infantry factory Untere Nase A 2226: Entrance, Mg stand 2 «Rita» ⊙
- Infantry factory Untere Nase A 2226: Mg stand 4 «Lotte» ⊙
- Infantry factory Untere Nase A 2226: Mg stand 3 «Rolf» ⊙
- Infantry factory Untere Nase A 2226: MG stand 1 «Kathia», 9 cm anti-tank gun «Laura» ⊙
- Infantry Works Lower Nose A 2226: 7.5 cm BK «Ruth» ⊙
- Infantry factory Untere Nase A 2226: searchlights, emergency exit ⊙
Sea obstruction Nas
In 1940 the planning of a floating lake obstacle was started in order to be able to close the Nasengnis Nas. The Pontonier Battalion 2 made its first attempts and the Pontonier Company I / 2 created the obstacle in July 1942 under the direction of the chief geniuses of the 5th Division and the 2nd Army Corps. General Guisan inspected the completed sea obstruction on July 30, 1942.
The obstacle was a combination between a triangular footbridge and a Spanish rider and was around 1130 m long. The wooden structure, floating on tree trunks, had a 2.5 m high triangular structure, was wired with barbed wire and anchored to the lake bed with wire ropes on concrete blocks weighing 2.5 tons. In the middle there was a passage opening of approx. 100 meters for the ships, which could be adjusted depending on the level of readiness. The sea obstruction was maintained and monitored by the pontoon company I / 2 and the motorboat detachment 5 and protected by the flanking coastal batteries Ober Nas and Unter Nas. After the war ended in 1945 the obstacle was completely dismantled.
- Sea obstruction Nas ⊙
Motor boats
The motorboat formations formed ad hoc were an essential part of the defense system of the Nas lake barrier . Due to the use of seaplanes ( Heinkel He 59 ) by the German Wehrmacht during the invasion of Norway and the Netherlands in 1940, the Swiss army command began to equip private boats requisitioned on various lakes with machine guns. From 1941 the first ad-hoc combat boat, sea transport and sea liaison detachments were introduced in the central area (Reduit). On Lake Lucerne, in 1943, the ad hoc units were formed into the Motorboat Detachments (Mot Boot Det) 4 (North: Rütenen ) and 5 (South: Brunnen and Hertenstein ), which were subordinate to the 5th Division .
literature
- Hansjakob Burkhardt: Fortification “Seesperre Nas” and Swiss Navy on Lake Lucerne. Nidwaldner Museum, Stans 2005, ISBN 3907164148
- Gregor Bättig: The defense efforts in the Nidwalden area 1935–1995 . 150 years of Nidwalden Officers' Association, 1857–2007. Aktiv-Verlag, Stans 2007, ISBN 3-909191-36-3
Web links
- Official homepage of the Vitznau Fortress
- Vitznau municipality: Vitznau fortress
- Military monuments in the cantons of Nidwalden, Obwalden and Lucerne
- Nidwalden Museum: Nas lake barrier and Swiss Navy
- Association of IG Patrol Boat Uri
- Historical aerial photo (1943) of the country's topography, the barrier elements of the lake barrier are clearly visible
Individual evidence
- ↑ Funicular railways Switzerland: 6442.01 Gersau Infanteriewerk Ober Nas - Gersau Kantonsstrasse
- ↑ Fortress Oberland: A2215 / A2226 Artillery Works Obere Nas LU / Untere Nas NW
- ↑ Historical naval archive: In 1940 84 operational He 59s served as transporters for attack troops and equipment for the combat group z. b. V. 108 on the invasion of Norway. On May 10, 1940, 12 He 59s of the 3rd Combat Group zbV 108 flew into the port of Rotterdam to invade the Netherlands and occupied the port. Archived copy ( memento of the original from March 8, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Hansjakob Burkhardt: Fortification "Seesperre Nas" and Swiss Navy on Lake Lucerne. Nidwalden Museum, Stans 2005
Coordinates: 46 ° 59 ′ 42.8 " N , 8 ° 28 ′ 31.2" E ; CH1903: 678 853 / two hundred and five thousand four hundred and twenty-eight