Dave Saxton wrote:alecsandros wrote:What do you mean by "underneath her" ? Torpedoes that come up vertically and hit the ship exactly at her maximum draft ?
The most devastating torpedoes are those designed to pass beneath the target and explode some meters below the keel triggered by the magnetic field. In addition to the shock wave, a giant bubble is created and the great mass of the target ship is no longer supported by sea water. This breaks the back of the target ship. There's really not much in terms of torpedo defense system design that can counter this. I doubt that Vanguard could survive this kind of attack if it was more than one.
The Tirpitz is the only warship that I know of which survived very powerful mines (2,000 kilograms-4,400 lb- of Amtex high explosive) exploding some meters underneath it or almost directly underneath it. Part of this survival was the structural design of the armoured longitudinal bulkheads and the low positioned panzer deck. These structures formed it effect a giant H-beam over the entire length of the citadel that the rest of the ship was constructed around (See MA6).
Dave Saxton wrote:tommy303 wrote: Large vessels like Vanguard normally had degaussing coils built in to them for protection against such weapons. These reduced the magnetic field around the vessel to below that which would activate the mine or torpedo pistol. Post war, however, magnetic pistols became even more efficient and utilized a system which would sense any change in the magnetic field, allowing even a degaussed vessel to be attacked; this led to a post war mini technology race in improved degaussing vs improved magnetic weapons.
When the British first started testing PPI radars, it was found that de-gaussing could not be used with PPI type CRTs. It would throw the PPI indicators completely out of whack. If the de-gaussing was switched on then it was a long, labor intensive process to restore the radars to functionality. It doesn't appear to have affected magnetrons to as great a degree as CRTs. This may have been why the Germans used electro magnets (adjustable gauss and switchable on/off) for magnetrons and deflection circuits of the Berlin PPI radar systems.
Now that's quite a mouthful. thank you for taking the time to explain it all, dave.