Site Records

Site Name: Castel-Vendon Battery & 'Silos'

Near Cherbourg

Sub Brit site visit 28th November 2004

[Source: Nick Catford with historical text by Philip Henshall]

In 1924 the French Navy ordered several 13.4 inch (34cm) turret-mounted guns from the arms manufacturer Schneider. The guns were to be added to naval bases on the coasts of Tunisia and Algeria and further south at Dakar. In addition, two similar guns in twin turrets were to be added to the coastal defences around Cherbourg and the site chosen was Castel-Vendon, 5 miles west along the coast from Cherbourg. The guns which would have had a range of nearly thirty kilometres arrived at Cherbourg in 1928 but because of cuts in defence spending they were put into storage at the naval base.

The lower map shows the military exclusion zone fanning out into the English Channel

In 1935, as war clouds began to gather over Europe, France rapidly began to strengthen its defences and work started at Castel-Vendon. Two concrete 'silos' were built to mount the guns a short distance back from the cliffs; these were connected by tunnels and had underground accommodation for personnel and munitions for the guns stored at Cherbourg. The work had not been finished and the guns had not yet been installed when the German forces arrived at Cherbourg in July 1940.

Silo 1 was complete but not fitted out, Silo 2 was partially complete and the underground workings were about 75 per cent finished. In 1942 the Germans started work at the site, initially as part of the West Wall, and added a battery of four Skoda 6 inch SKC/28 guns in separate M272 concrete casements, together with two 2 inch guns and range-finding bunker on the edge of the cliffs. A two level M162A fire control position was planned but this was never built. The main battery was between the silos and the cliffs.

Photo:No. 1 Silo built to house a 13.4 inch turret mounted gun
Photo by Nick Catford

It is unclear what happened to the two guns. They may have been scrapped and melted down before the war but this seems unlikely. Had they fallen into German hands they would certainly have been used.

It has been suggested that the partially finished French silos were later used by the Germans as a launch site for V2 rockets.

The unfinished No. 2 Silo - Photo from Bunkersite web site

This however is not true. Silo 1 could not accommodate a V2 rocket vertically because, although it was wide enough, it was only 37 feet deep, compared to 45 feet required for a V2.

Silo 2 could not accommodate a V2 because, although it was deep enough at 55 feet 10 inches the diameter of the lower 19 feet 10 inch section was only only 7 feet which was too narrow for a V2 with fins fitted.

The lowest level of this silo was blocked with two steel beams, effectively providing a floor at the 55 feet 10 inch level.

A third silo is also to be found close to Silo 2. French plans of the site do not show a third silo and therefore it was assumed to have been built by the Germans. This was of similar dimensions but was roofed over at ground level with access steps leading downwards at one edge.

Tunnel network linking No 1 & No 2 Silo and No 2 Casemate

There is no doubt that the site was inspected by the Germans after July 1940 and the original French work would certainly have been of interest. From 1943 suitable V-weapons sites were being inspected in northern France and there is a good chance that Castel-Vendon was noted for inclusion in the site building programme. The presence of the coastal battery provided perfect camouflage, since Allied Intelligence was concerned with V-weapons and so showed no interest in additions to the West Wall fortifications.

The differences between Silos 1 and 2 raises the question of why they had different dimensions when the two turrets they were originally intended for were presumably identical. The existence of Silo 3, with a similar outer diameter to the other two silos but not shown on French plans, indicates that something other than West Wall fortifications was planned for the site.

The vaulted chamber at the base of No. 1 Silo
Photo by Nick Catford

A Rheinbote is the only rocket that would conveniently fit the dimensions of Silo 2 and the Rheinbote could be launched vertically (although this reduced its range to less than 100 miles) but there is no evidence that any of the three silos were ever used for launching rockets so the WW2 use of the two French and the later German built silo remains a mystery.

For further information and pictures about Castel-Vendon click here

[Source: Nick Catford with historical text by Philip Henshall]

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