|S-Boats in the Kriegsmarine - S-Boat-Bunkers|
S-Boats in the Kriegsmarine 1935 - 1945
Already in 1940 it was to bee seen that the S-Boats in the channel-harbours of France and Belgium and in the harbours of the Netherlands would be strongly endangered by airattacks of the Royal Airforce. Therefore, in 1940 the planning of Schnellboot-Bunkers (Schnellboot-Bunker [SBB]) was initiated. The first plans included SBBs in the harbours of Cherbourg, Boulogne, Ostende, Ijmuiden, and Rotterdam.
For the bunkers the following number of berthes were planned:
In Cherbourg, which had been reported as a S-boat-base on 23.06.1940 by the F.d.T., the partly destroyed facilities of the Arseal were covered by a barrel-shaped vault. During the war a second SBB was built with a barrel-shaped vault which encluded exosting dockfacilities. SBB I was built from August 1940 onwards over the drydocks for submarines. Teh vault was 3,5 m in thickness at a length of 106 m and a width of 28 m. This bunker is still existing today and is used for smal boats of the harbour facilities. SBB II was built from September 1943, it covered the docks on the southern side of the outer harbour. It was about 28 m wide and 90 m long. The construction was not completed until the invasion by the Americans end of July 1944.
SBB Cherbourg - Picture: M. Foedrowitz
SBB Cherbourg with small craft of the harbour authority - Picture: M. Foedrowitz
In Boulogne, which was thought to become a base for S- and R-boats, a SBB was built starting in 1940, at the construction of which, the young civil engineer Fähnr. z.S. Eugen Stroh was acting as site manager. From his archives are the pictures of SBB Boulogne. On 21.06.1941 the first four boxes were ready and were used by boats of the 4. SFltl. A further extention of a length of 116 m and a width of 50 m for four aditional boxes was following. The strength of the cover was at 3,5 m, the walls 2 to 3 m. Both bunkers were built on a founding of 18 - 20 m long stakes. In March 1942 the Site Management Boulogne was transferred to Guernsey to build bunkers and guntowers there.
Moulds for the bunker walls at Boulogne on stakes of the foundation - Picture: Archives M. Lohr
SBB Boulogne, to the left the bowex of the first construction section - Picture: Archives M. Lohr
High ranked visitor at the SBB Boulogne - Picture: Archives M. Lohr
Also the start of constructions at SBB Ostende is not documented. But on 10.06.1941 the Harbour Construction Office Ostende reports that the first construction section is completed and four boats can be accommodated. At the end of the month als boxes in Ostende were completed.
SBB Ostende - Picture from Feodrowitz Bunker an der Kanalküste
Also for the SBB Rotterdam no date for the start of constructions is known. On 11.10.1941 the first boxes were completed. The outer walls and the ceiling were made of 3 m thick reinforced concrete, the bunker contained not only 16 boxes for boats but also torpedo-. motor-, accumulator-, wireless radio- and radarworkshops. On 05.10.1941 the first boats entered the SBB.
SBB Rotterdam Waalhaven - Picture: Unknown
SBB-Ijmuiden - Picture: Unknown
Unmooring in a Channel harbour SBB - Picture: PK-Foto
Flotilla leaving for a night attack - Picture: PK-Foto
Boat entering SBB Rotterdam - Picture: PK-Foto
Berthing in a SBB after an attack - Picture: PK-Foto
Torpedo replenishment in a SBB - Picture: PK-Foto
S-Boats in their bunker - Picture: PK-Foto
Pre-exit muster in a SBB - Picture: PK-Foto
Flotilla-muster by the F.d.S. - Picture: PK-Foto
The F.d.S. demanded primarily two more bunkers for Den Helder and Le Havre. Upon finalization of the planning for a S-Boat-bunker at Den Helder a construction site was established, which was abandoned in order to avoid a too extensive concentration of boats and because of the difficult ice-conditions. For Le Havre and Dunkerque R-Boat-bunkers were built.
1943 the F.d.S. demanded new bunkers and requested extension of the existing bunkers:
In fall 1943 a second bunker for Ijmuiden was requested, in order to have 42 berthes available. Because of the developments of the landfront the bunkers at Boulogne and Ostende were no longer considered for an extension. The other bunker projects were not realized.
Drawing of the planned SBB Den Helder
The bunkers with their partly over 10 ft thick steel-reinforced concrete roofs seemed to ensure full protection of the boats for a long time. To support the Allied landing in Normandy the Royal Air Force dropped extra heavy bombs, so called "Tallboys" directly targeted on the bunkers, so that their roofs were penetrated.
the night of
13./14.06.1944 the boats were again to attack the landing fleet, the 5th
and the 9th flotilla were to go to Cherbourg because of the concentration
of boats at Le Havre. But wind from nordwest with Beaufort force seven
forced to boats to break off their action and to return to Le Havre. The
communications traffic was intercepted and deciphered and the Allied
attacked the boats with 221 Lancaster-Bombers guided by fighters and
Mosquito-fighterbombers in the evening of the 14.06.1944. 14 S-boats (S
84, S 100, S 138, S 142, S 143, S 144, S 146, S 150, S 169, S 171, S 172,
S 173, S 187, S 188, S 188) and
three of the four torpedoboats in harbour were sunk, only S 167 escaped by
lelaving harbour. In the bombing 18 soldiers were killed, among them the
commander of the 5. SFltl (KptLt Johannsen), furthermore there were 25
wounded to mourne, among them the commander of the 9. SFltl (KptLt v.
Mirbach) and four boat captains.
During the following night a new air raid was conducted on Boulogne. While nine minesweepers, two guard vessels, and three mineswepper tenders sunk, the 2. SFltl could leave harbour early enough, before the S-boat-bunker was penetrated by bombs and remained without noteworthy damage.
The air raids of these two nights had weakened the navy in the channel decisively, of 31 S-boats at the outset of the invasion in the four flotillas 13 were still operational:
SBB Rotterdam - Picture: Archives Enno Brandi
SBB Rotterdam after a Hit by a Tallboy-Bomb - Picture: Archives Enno Brandi
SBB Ijmuiden after a Hit by a Tallboy-Bomb - Picture: Archives
The remains of the s-boat-bunkers have existed for many years after the war. Partly they were used as berthes of harbour authority boats, partly for settling of industry.
SBB Ijmuiden as industral site - Picture: M. Foedrowitz
Chalok-Sand-Stones are produced here - Picture: M. Foedrowitz
The Schnellboot-Bunker Ijmuiden is at present under destruction. The destruction is shown in a YouTube-Film.
Besides of the Schnellboat-Bunkers in the bases at the coast of the Channel and the sothern Northsea Torpedo-Bunkers, Ammunition-Bunkers, Fuel-Bunkers and Air Raid Bunkers for the crews were built.