Unsinkable ships

[fvd]

Hi guy's,

I'm using the Trigger-Maru mod now for a couple of days, and also Natural sinking mechanics.
It's really hard now to sink a ship, maybe too hard?

For example: a medium split freighter took 2 torpedo impacts, one just before the bridge, the other one after the bridge.
I waited about 20 minutes, she did'nt went down.
Tried to finish her off with my 4,5" deck gun.
She's taken more then 80 shells and she's still floating.
Not even a fire broak out on board!
These japanese engineers really build superior ships

I'm not sure, but i think that if a 2400 Ton's ship gets hit by two torpedo's, she probably will go down, maybe even break apart?

Am i wrong or is there something not quite correct?
Maybe the power of the torpedo's is too weak, or the ships too strong?

Regards,
fvd