[TorpX]

Originally Posted by commandosolo2009

I thought the ideal angle was 110°

The optimum track angle relates to having the greatest error tolerance in the targets course. It really has nothing to do with potential duds, target evasion possibilities, tactical factors, etc. It is not a comprehensive optimum angle, but gives the least deflection error for a given error in target course. The 110 deg. angle is not fixed, but only a "typical" optimum as it is a function of both torpedo speed and target speed.

It can be calculated thus:

Optimum track angle = 90 + Arcsin (target speed / torpedo speed)

This was part of USN doctrine, and is shown here (plate XVII, XVIII):

http://hnsa.org/doc/attack/index.htm#platexvii



BTW, O'Kane talks of setting up attacks and using this. Clearly, he understood the geometry behind this.