On 10.06.1941 the harbour construction office (Hafenbauamt) Ostende reported, that the first construction-phase was ready and four boats could be accommodated. On 21.06.1941 the readiness-report from Boulogne followed, end of the month all berthes at Ostende were ready. On 11.10.1941 the first boxes in Rotterdam were finished. End of February 1942 all units of the 2. SFltl could get shelter in the SBB of Ijmuiden. At Cherbourg existing berthes were covered by a vault of steel-reinforced concrete. There the boats could search for shelter as of January 1941.

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 a SBB - 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 buildling projects were not realized.  

Draein 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. 

During 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:

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 Cherbourg - Picture: M. Foedrowitz

SBB Cherbourg with small craft of the harbour authority - Picture: M. Foedrowitz

SBB Ijmuiden as industral site - Picture: M. Foedrowitz

Chalok-Sand-Stones are produced here - Picture: M. Foedrowitz

The Schnellboat-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.