The Atlantik Wall In Normandy

 

 

 

V1 Light Sites

The Term Light Site refers to smaller construction and resources needed to launch a V1. The Allies called them modified sites, but in reality they were a new concept. After the SS took control of both the V1 & V2 projects in 1943, and because of the Allied bombing of the Ski sites this light site was conceived.

The V1 sites in West Normandy are different to the other light sites in as much as the buildings were much simpler. In the east of France many of the workshops had extensions, but here in the west I have never found anything other than the main workshop. They are often referred to as Garages, but I think this must have been a mistranslation as no vehicles were stored in them, except in later days after the war when most were and still are used by local farmers as just that "Garages". I am not sure about doors on the workshop, I am inclined to think that the hinges that are on some buildings are from after the war and that wooden shuttering was used when the workshop was not in use, rather like that used on gun emplacements. The other important difference is that in the East of France each site was equipped with a steam generator to launch the V1. In the Cherbourg Peninsula this was replaced by chemicals. Hydrogen Peroxide and Potassium Permanganate, which when mixed together give twenty times the volume in instant steam. The V1 could not fly off the ramp and was thrown into the sky with a system very similar to that used on an aircraft carrier to launch planes. Only Brecourt had a steam generator left by the French.

The V1 would be brought by road from the reception site and be made ready for immediate launching.  Unlike the "Heavy Sites" there was no storage facility at any of the 30 Light sites" The workshop is of a standard design, but with all German construction the are minor differences. I am not sure what tasks would have already been completed at the reception site, but in preparation for the launch the following would have had to completed.

All of the mechanical items bolted into the V1 and checked. Then the warhead would be installed. The V1 would be despatched to the launch site. On arriving at a Light site the V1 would be taken from the truck and placed on a non magnetic trolley, probably made of wood with non ferrous wheels, although there are photo's of the V1 on what looks to be an aluminium trolley.  As the whole idea of the V1 was not to use valuable resources I prefer to think they were made of wood, as they had to have no magnetic influence to interfere with the compass. On arrival in the workshop it would be wheeled inside, but not completely as the workshop is only 7.5 meters long and the V1 is 7.75 meters. The only photo I have seen shows a V1 with its wings folded flat alongside the fuselage and half in the workshop. Here the kerosene (low grade petrol) would be pumped into the fuel tank, the compass and gyroscopes checked and the batteries installed. The compressed air cylinders filled and the auto guidance set. The wooden wings would now be fitted. It would then be wheeled to the anti magnetic platform. This has two parallel groves cut into the concrete base. The anti magnetic platform has no reinforcing metal in it as this would interfere with the compass. Several sites are supposed to have been sabotaged by the workers, by throwing nails into the concrete mix.

These groves were aligned to the same compass direction as the ramp The V1 would be suspended from a gantry and the compass set. I have been told that because the V1 body is made of steel it already had a magnetic field and had to be degaussed. This was done by heating the V1 body with gas torches and hitting it with hammers!!

The fuze would then be fitted, these were kept several hundred meters from the site in small concrete or wooden boxes, usually in a hedge. Not many of these survive today.      At the launch site the V1 would be placed on the ramp, the trolley used to transport the V1 to the ramp (pic on right below) was aligned with the ramp using guide rails. The V1 was then slid up onto the ramp.

         

The launch ramp was around 9 meters long, made of metal with legs that fitted into concrete blocks and would have a small bunker to control the firing. These came in "Kit Form" each unit being 6 meters long, six and in some cases seven units formed the compete ramp. These could have been moved from site to site and would take around two hours to assemble. It is doubtful if more than one or two test units had arrived by D-day. The legs of the ramp sat in recesses in the concrete blocks, and in several cases the wooden shims which were driven in to ensure a solid fit between the concrete and the legs are still in place after all of these years.

The pulse jet engine was started using acetylene gas, often the exhaust had to be blanked off using a piece of wood to achieve ignition.  The Hydrogen Peroxide and Potassium Permanganate, would arrive already pressured in a trolley resembling a portable welding kit. The launch requires around a 100 litres of chemicals, and these had to be fed into the ramp under pressure. It must have been achieved by bolting the trolley to the ramp, and in many photo's the end of the ramp looks incomplete, with something missing. This was for the trolley, there are also bolt holes in front of some ramps. (pic extreme right below) These could have held a guide rail to ensure the alignment of the trolley.  The V1 motor is started and the order to fire is given. The two chemicals are fed into the ramp and instant steam is formed. There was a sheer pin holding the piston back until the pressure was great enough to break the pin and the V1 was on its way. at the end of the ramp the piston fell to earth and was retrieved to be used again. After the launch both the ramp and crew (who wore rubber protective gear) had to be washed down with water and a small reservoir can sometimes be found alongside the launch ramp.

To fire the V1 the only control must have been the introduction of the two chemicals into the mixing chamber on the ramp. This was done from a small bunker close to the ramp, a small portable electrical box completed an electrical circuit, and allowed the two chemicals to enter the piston chamber. When the desired pressure was reached a shear pin snapped and the V1 was on its way.  Follow the links below to view maps and photo's.

The two pages below have large maps and a good number of photo's they are slow to load, please be patient.

 

Home Up Light Sites 139-148 Light Sites 223-242

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