[TorpX]

Originally Posted by HertogJan

Hi TorpX,


I have a question bout the max surface range and submerged range for the Porpoise class you set ISP 2 (TMO) too.
_TMO =13358m at 13.5Knts
_ISP 2.4 =8114m at 10knts
(13358m at 10knts sounds about right to mee).

I've been looking at different sites for references and keep getting the aprox same surface range which are between 12.000Nm and 13.000Nm for te Porpoise class but when I look at your settings (s3d) they show 8114 miles which is
7050.8 Nm.

Ok, for the surface ranges, the ISP values are based on Norman Friedman's work, US SUBMARINES THROUGH 1945. He lists the Porpoise as having 6,000 nm range. Later 'P' class boats had a longer range, but I decided to go with the lower figures, as it didn't make sense to have 2 'P' classes. Then I took the 6,000 nm figure multiplied it by 1.3, because the Navy was said to incorporate a 30% fuel margin for battery charging. Then I added a small 'flat-earth bonus' to account for the map distortion in the game. About 5%, iirc.

Players tend to like mods that give then more range, firepower, etc., but I wanted this to be a high realism mod. Subs did run short of fuel, and have to cut short patrols. It was a operational fact of life. That's the biggest reason why the USN set up forward bases, when the opportunity came. If anything, I think the fuel/range figures are a bit generous.

The submerged ranges are arbitrary, and cannot be compared to any reference figures, because of the way the game battery performance is totally broken. Many who wanted to mod the game have found this out. You cannot get sensible submerged ranges just by putting the numbers in the *.sim files. It won't work!

The figures in the mod will give you approximately historical submerged ranges, but not exactly. I had to compromise, because there was no way to make all the numbers come out right for all the classes of boats. The S-class have somewhat less range than the references state, and the fleetboats somewhat more. Nevertheless, performance is much closer to real-life than before.



About the draft ht. and mast ht. I didn't change any mast height figures for obvious reasons. As far as the actual drafts of the ships, I made changes here and there as required for their stability. These changes were mostly small ones. There may be slight differences in your stadimeter readings for this reason, but I would not be unduly concerned. There is no way any skipper could know the exact draft of any ship, except his own. They varied according to the load carried.