Thanks fellas
Drake that page on explosives was fascinating, i even downloaded and read the report on the sinking of the Tirpitz.
Freiwillige some good pics there, and some big holes.
I understand you Fluffy, displaced water moves towards a path of least resistance, ie air.
In RL the destructive force of a torp was affected by several factors, not least of which would have been the amount of armour blocking it's path.
( Note there ref. the Tirpitz anti-torpedo bulkheads, which were designed to withstand a greater amount of hexanite explosive than used in German torpedoes of the time).
Unfortunately SH3 makes no such destinction, and with the SH3 torps being capable of penetrating even the heaviest armour levels, will destroy the same zone area on a battleship as on a merchant.
The simplest solution would be to reduce the strength of the torpedoes, which worked great on the A/C's and battleships, producing much more realistic damage effects and survivability of engines further from the blast radius of a magnetic.
Has to be said that anything that reduced the strength of the torps would be unpopular though
Unfortunately it also produced an anomoly in the case of the Glorious, with her concave hull bottom.
On one occasion 2 magnetics detonated under the engines, without stopping any of them or even lowering her draft. She just carried on regardless.
It seems that although SH3 doesn't compensate for armour, it does compensate for the amount of water between the detonation and hull contact, reducing it's effectiveness considerably.
I've had some success by lifting the engine zones towards the waterline, further from the blast radius, and replacing the lost bouyancy caused by the smaller engine zones with " dummy" zones. Effectively a twin layer of engine zones.
It may look a unrealistic in the zone model, but if it produces a more realistic damage effect i figure that's what counts.
I see no point in setting up British ships realisticaly as possible if i can't emulate realistic damage resistance to torps.
Thanks guys, i'll keep working on it