[TorpX]

Here is the link:

http://pigboats.com/subs/s-boats.html

Scroll down to the tour of the S-4.

Regarding torpedo load-out, there were two major classes of S-Boat. Most had no stern tubes however an aft tube was added on some, which would make the total for those boats 14.

The loadout discussed was for the bow tubes only and the boat had no rear tube.

The battery recharge time even according to RFB and Ducimus' TMO would be accurate due to the 2 small WWI era engine reason mentioned above.

I would agree if you were charging fleetboat batteries with S-class engines. The S-class were smaller, slower boats with less machinery, less performance, and smaller crews. They did not need the same battery capacity (in kilowatt hours) of a fleet boat. The batteries would be appropriate to the type of boat.

The total battery capacity for the S-4 was given as 1,240 KWH. I could find any specs for a fleet class, but I would guess it to be at least double that.