Folks,

Remember that you are dealing with a 1940's weapon here,no miniaturised electronics at all. The FIDO was a triumph of design,no doubt...but remember the specification...its was designed to defeat U-Boats running underwater so it did not have to be much faster than 15 knots to catch the sub. The designers of FIDO had to INVENT all the techniques to quieten the torpedo.They mounted the motor on rubber pads,dispensed with contra-rotating propellors as the gear whine for this was very noisey. There was an 'aucoustic bulkhead' just forward of the engine to cut noise transmission from the motor to the sensors. The four sensors which were in the torpedoes nose were also mounted on flexible mountings again to cut down self noise. Making FIDO faster might have overwhelmed its ability to hear its target.

It is worth noting that after the war the British and U.S Navies both evaluated captured german aucoustic torpedoes and the conclusion of the British scientific panel assigned to this concluded that the weapon (The 'Falke' or 'GNAT' to the British) was highly marginal in its ability to sucessfully tract surface targets. The reasons for this was excessive self noise (virtually no quieting like the FIDO) and its high spped necessary to catch surface escorts (again high self noise).

It seems that the Germans were aware of at least some of the problems with their guided torpedoes as they had developed by the end of the war two 'wire-guided' torpedoes 'Lerch' and 'Greir'. These torpedoes were guided to their targets by operatotrs on the U-Boats listening to the sounds being heard by the torpedeo and guiding them manually onto their targets.

Rgdrs

Sniper.