I'll check it out when I get time. Thanks!
I know that one of the fixes in NYGM was lowering the chance of fire to keep in check with reality. Most torpedoed allied ships just report a dull thud and flooding. Plus a wrecked deck usually. The detonation was enough to compromise watertight barriers so it was just a matter of time until sinking. Fire was very rare and, like you said, had a much higher chance if it was a tanker.
Cheers
Edit: is there a trick to setting precise headings? The stock blow up compass is not good for this.