Hohlgangsanlage are a number of tunnels constructed in Jersey by occupying German forces during the occupation of Jersey. The Germans intended these bunkers to protect troops and equipment from aerial bombing and to act as fortifications in their own right.
The word Hohlgangsanlage can be translated as "cave passage installations".Jersey's German Tunnels by Michael Ginns MBE, CIOS Jersey The Channel Island tunnels are the only ones on the Atlantic wall to be referred to as Hohlgangsanlagen.
All the tunnels except for Ho5 are incomplete, and some never progressed beyond planning. The partly complete tunnels are, nonetheless, substantial in size. Completed sections were used for various purposes such as storage.
In 1944, when construction stopped, 244,000 m3 of rock had been extracted for tunnel digging collectively from Guernsey, Jersey and Alderney (the majority from Jersey). At the same point in 1944, the entire Atlantic Wall from Norway to the Franco-Spanish border, excluding the Channel Islands, had extracted some 225,000 m3.
History 1941–present day Tunnel construction began in 1941, shortly before Hitler's October 1941 decree that the islands be defended. The tunnels were constructed at strategic points around the island. Most of the tunnels were for shelter or storage, but some were used as part of and to link fortifications in strong points (such as at Corbière) and were part of casemates. The tunnels were constructed by the Festungsbaubataillone (fortress construction battalions), 4/Gesteinsbohr-Kompanie Btl. 77 (specialist mining battalion), the RAD (state labour for 17- and 18-year-olds) and the Organisation Todt. The Germans used a variety of labour sources, most being forced. After Todt's death in February 1942, Albert Speer drastically reduced the resources available for the construction of tunnels on the island. During 1944, there was a shortage of raw materials, so effort was diverted to finish only the most complete tunnels. On 9 May 1945, construction stopped with the liberation of Jersey.
Only a few tunnels were actually used by the Germans: Ho1, Ho4, Ho5, and Ho8; of these, only one was actually completed (Ho5) and the others were used while partially completed with unfinished galleries being walled off, or left with pit props in place.
Immediately after the war, the British used the tunnels: soon after the Liberation of the Channel Islands, some military equipment was moved and stored in the tunnels. For example, Ho1 stored weapons, Ho2 stored small equipment such as helmets, gas masks, fuel, oxyacetylene, and field kitchens. Ho13 stored Panzer Abteilung 213's Char B1 bis tanks.German Armour in the Channel Islands 1941–1945, Channel Islands Occupation Society (Jersey Branch), Panzer Abteuilung 213 in Text and Pictures, Archives Book 4, By Micheal Ginns
During the 1950s scrap metal drive, the tunnels were mostly cleared and sealed. Under Jersey law, a landowner owns everything beneath his land, down to the centre of the earth, so all the tunnels are privately owned. Hohlgangsanlage 8 is the only tunnel open to the public without special permission from the land owner; it was opened to the public in 1946 by the British army, then gifted to the States of Jersey by the War Department. After a lawsuit by the owners of the land above, it became privately owned but still operates as a museum today.
After 1962, all the tunnels were thoroughly cleared of German equipment (apart from the museum, Ho1 due to roof collapse and Ho4 due to masses of barbed wire, roof collapses and unexploded ordnance) after a tragedy in which two souvenir hunters died of carbon monoxide poisoning in Ho2.
The tunnels are very unstable, as most were bored not into solid granite, but loose shale. This is evident from the large number of roof collapses in the incomplete, unlined tunnels. Most of the tunnels still survive today, and are infrequently visited by organised parties (with permission).
There were plans to use some of the tunnels during the 2009 Swine flu pandemic, which ultimately never materialised.
Construction and design
The tunnels were dug into the sides of hills, into rock. This means that incomplete tunnels remain mostly intact, due to the strength of the unsupported rock. Completed sections are lined with concrete floors, walls, and ceilings.
There was a basic design of storage and personnel tunnel. Storage tunnels incorporated a gauge railway in a loop running around the whole complex and a small platform for loading supplies; they usually had two entrances so that vehicles could continuously enter and exit the complex. Personnel tunnels were built like a grid; the railway was often removed after construction was complete. Completed tunnels would have been lined in concrete, and have drainage, lighting, and air conditioning systems.
In all, 19–25 storage tunnels were planned but, due to the almost wholesale destruction of primary source material before the surrender, the exact number is unknown (although the number where work began is known).
Where possible, the tunnel routes avoided granite and instead they were routed through looser shale rock formations; this speeded up construction and was less labour-intensive, but it could also be dangerous due to an increased risk of rockfalls. The tunnels were dug by the traditional method of drilling and blasting. When the tunnels were bored out, they were lined with concrete. First, the floor was lined, followed by the walls, and, finally, the roof. The walls were concreted using wooden shuttering, the space between the shuttering and the rock face was filled with concrete, and the shuttering subsequently removed. The roof was made in the same way, but using curved shuttering balancing on the concrete walls. Concrete was poured down the escape shafts rather than through the tunnel entrances to avoid contamination with the rock leaving the tunnel; these chutes can still be seen in many of the tunnels.
Contrary to popular belief, there were relatively few accidents and deaths in the building programme itself, but many slave labourers died of starvation.
The tunnels
Storage tunnels Tunnels used only for storage Ho1 .Hohlganganlage 1 Munitions Storage Tunnel (Munitions Store I) – Incomplete, dangerous and private - West side of La Route d'Aleva (The German Road), St. Peter's Valley. Ho1 unfortunately, was never completed. That being said, construction was sufficiently advanced to permit the storage of ammunition from May 1944. By the end of the war, some 6,000 tons of ammunition had been housed within this complex. Had it been finished, the British Army estimated that the tunnel could have held up to 20,000 tons worth of ammunition. By the end of 1945, the ammunition had been removed for disposal. The British Army did however see Ho1 as a suitable place to dump German equipment, instead of dumping into the sea. Future archaeologists and adventurists would be left disappointed as scrap metal has its price in 1953. A major scrap metal hunt lead to most items being removed. In more recent years, the tunnel has been used for various reasons. Providing winter storage for laid up hire cars and coaches, while some galleries were used by the local rifle club. Subsequently, for many years, the tunnel was primarily used as a mushroom farm. A victim of rising costs, the mushroom farm ceased operations in 2006. Within one of the primary tunnelling sections, as of 2025, remains an old Allied Jeep that has remained since 1946. Ho2 (Ration Store I) – Incomplete, dangerous and private – East side of The German Road, St. Peters Valley. Like Ho1, this tunnel was constructed with multiple entrances and semi-circular primary galleries and indeed could be said to be a mirror image of its neighbour tunnel just across the valley. Tunnelling began in 1942, the work being carried out by a German contracting firm, using French North African forced labourers and Russian slave labourers. Consequently, the workers were treated poorly and accidents were frequent. By mid 1944, construction was far from complete. The primary galleries were still unlined, and remain so as of 2025. However, the main galleries are in fact complete to a very high standard. It is believed that liquid concrete was poured down the escape shaft rather than carried in from the entrances. Ho2 is the only tunnel on Jersey, that was contracted back to front. Similarly to Ho1, the post war British Army saw the tunnel as an opportunity to hide what remained of the German Army. Circa 1947, the tunnel was sealed but not sealed to a proper standard, as the British Army believed that Jersey population would either be too intimidated to enter or would just move on and forget - This however, was not the case. As a consequence of the poorly sealed tunnel entrances, intruders were frequent in the 1950s/1960s mostly made up of the younger generation that were either too young to remember the occupation or weren't even alive, but were fuelled by an adventure of discovery the unchartered. The first sign of impending disaster occurred in 1952 when two youths ventured into the tunnel one night. They had told a friend about their adventures so when they failed to return home the following day a search party was sent out. The youths had entered into the tunnel with one torch between them and without the slightest knowledge of the tunnels layout, which at the time was still rammed with German equipment all shapes and sizes. Their torch failed when they were in the heart of the complex and they, as a result were totally lost. They spent their whole night trying to locate an exit . The following morning at 09:00, the two boys were rather relieved when a search party located them. The tunnel was immediately sealed, once again. In 1960. the local Evening Post, threw serious shots at the public warning them of the serious dangers and drew attention to the fact that every Sunday afternoon, 20 bicycles would be found lying outside the tunnel while their owners explored its interior. Tragedy eventually struck on the afternoon of Sunday, 27 May 1962, when two 15/16-year-old pupils from Victoria College were overcome by fumes in the tunnel and asphyxiated. After intense investigations, while in typical dramatic Jersey fashion, the local rumour was that of "Nazi gas kills youths!" - it was eventually discovered that the tragedy was due to a bonfire having been lit in the tunnel a few days beforehand, with only one small entrance to Ho2 being open at the time, therefore all the oxygen had been consumed. Ho3 (Munitions Store II) – Planning stage only – Upper end of The German Road, St. Peters Valley. Although the tunnel never got beyond the point of planning, it would appear to have been sited in the vicinity of what was formerly Jersey Coal Distributions' yard.