German fortification of Guernsey
Because the Germans expected to invade the United Kingdom in the autumn of 1940, they decided that expenditure on defences for the islands would be a waste.
Whilst the Luftwaffe and Kriegsmarine had their roles in protecting the islands from the Allies, the occupying forces put their main effort into land defences aimed at repelling a seaborne or airborne assault.
The resulting construction work in the Channel Islands was extensive; it required thousands of workers and massive supplies of cement and steel.
The "Westbefestigungen" (Inspector of Western Fortresses) was given responsibility for oversight and was required to generate bi-weekly progress reports.
[1]: 190–3 On 16 June 1941 Hitler's instructions to reinforce the islands were transmitted there from Oberbefehlshaber West; the rationale was that an Allied attack "must be reckoned with" in Summer 1941.
[3]: 8 The Regelbau (standard build) system used books of plans for each of over 600 approved types of bunker and casemate, each having a specific purpose.
[1]: 197 The outcome was a decision to provide for the “permanent fortification” of the Islands to make an impregnable fortress to be completed within 14 months.
Fortress Engineer specialist sub-units such as Compressor, Mining, Rock Drilling, etc., would move between the Islands as required.
Supervisors and OT labour was supplied to German construction companies, ten of which operated in the Channel Islands.
They were badly fed and clothed and were beaten and punished for minor offences;[11]: 33 the Germans considered them expendable and worked some to death.
[9]: 179–180 The OT hospital was at Ruette Braye, its fuel depot at Grandes Rocques, and timber and cement stores at St Sampson.
Holes through walls for ventilation pipes and cables, doorways and escape routes being put in before the concrete was poured.
Each location had defences and facilities to suit its specific needs, the thickness of walls, floor, and ceiling were standard.
Fittings such as air purification systems, showers, gas proof doors, telephones, periscopes, and wiring were standardised.
Using four barrels taken from a 1917 Imperial Russian dreadnought captured in Norway and resting on platforms manufactured by Friedrich Krupp A.G., these 30.5 cm guns had a potential range of 51 kilometres (32 mi) with lightweight high explosive shells, weighing 250 kg or 31 kilometres (19 mi) with the heavier 405 kg armour piercing shells.
[16]: 98–100 Battery Dollmann at Pleinmont is open to the public to visit; it has one of the four 22 cm gun pits and a number of trenches restored.
[16]: 101 Naval Range-finding Tower MP 3 at Pleinmont, which has 5 observation levels and had a radar unit on the roof, has become a museum, open to the public.
The initial plan was for two towers to observe a target and through measuring angles determine its distance and therefore grid reference.
L’Ancresse common has, in the middle of the golf course, the six gun Flak Battery Dolman, in concrete emplacements that could be used for a dual purpose as they commanded sea approaches with a 14,000m effective range.
Twenty one of the casemates built into the coast were designed for 10.5 cm K 331(f) French guns that had been acquired in large quantities.
At Fort Saumarez L’Eree headland, a trench system with machine gun and a Tobruk pit has been opened up and is accessible to the public.
Anti landing craft objects of steel and wood, thousands of tetrahedra and Czech hedgehog, often with teller mines attached on the beaches.
[22] Widerstandsnest (Resistance nest) (WN) formed a smaller defensive zone, filling in between SP's, and protecting specific points, like artillery batteries or a radar station.
Fourteen were started, few were completely finished, some were half built, others abandoned early when poor rock quality was hit, or priorities changed.
Once the fumes and dust had dispersed, the loose rock could be cleared, loaded onto wagons run out on 60 cm tracks and removed.
French Renault Char B1 tanks, destined for Rommel in North Africa in early 1942, also were diverted to the Channel Islands.
Activity decreased following the conclusion of the Battle of Britain,[16]: 51 with the airfield being used more for refuelling and inter-island communications rather than as a base for permanent aircraft.
[7]: 56 Camouflage in the form of paint, sprayed concrete and straw on wire mesh, and timber constructions were common.
Only about 30% of the original 319 ID personnel were still with the unit in June 1944, the fitter men having been sent to the Eastern Front, to be replaced with less fit and non German troops.
In September 1944 there were 10,980 troops in Guernsey comprising:[14]: 52 Commanding Officer of the German garrison, Lieutenant-General Rudolf Graf von Schmettow, nephew of Gerd von Rundstedt commander of OB West (Commander-in-Chief West),[1]: 195 ordered the writing of a 500-page book that described the fortifications in great detail, illustrated with maps, photographs and coloured drawings.
