Request for mod: Better engine RPMs
 

When submerged using electric motor, selecting KF (kleine fahrt) speed, the engine speed will be set to 100 RPM. Of course the primary use of KF speed is for silent running, and the way it is set up, it provides a speed which is not very silent.


To achieve actual silent speed, the player must switch to the knot meter, then try to click the exact pixel which gives the desired RPM. It is very fiddly and annoying.



According to http://uboatarchive.net/Manual/Manual.htm page 14, the actual KF engine speed was a much more appropriate 55 RPM.


My request is a mod that reconfigures the electric engine speeds on the engine telegraph so they match the numbers in the "owner's manual." Even if this were not historical it would be such a quality of life improvement that it would be well worth doing anyway. But it is historical.


It seems like such an obvious thing that I wonder why there is not already a mod to do it, but I cannot find one.

Just keep in mind that, from a historical standpoint, silent running was typically higher RPMs than 55 (which indeed was KF). They conducted extensive tests to determine the resonances and often (typically) the most silent RPMs were 20-30 RPMs higher. Like an old truck, maybe at a slow speed something rattled, until you reached a little higher speed, and then the rattle stopped. KF was the typical submerged attack speed, and it is also the speed at which the boat was trimmed during the daily trim dive, for that purpose, at periscope depth. Interestingly, the VII e-motors could achieve even lower RPMs than 55 or even 50, but not for any length of time because the motor’s field windings would get too hot.

But agree, from a gameplay perspective, it should be made to be easy to achieve the 55 with a click, as the game assumes “slowest=quietest”.

You can adjust it yourself and it's quite simple. You'll find the following values in the .cfg file for each U-boat in data/Submarine:

[EngineProperties]
AllStop=0.00
AheadSlow=0.40
AheadOneThird=0.57
AheadStandard=0.80
AheadFull=0.94
AheadFlank=1.00
BackSlow=-0.26
BackStandard=-0.40
BackFull=-0.53
BackEmergency=-0.66

As you can see All Stop is 0.00, Flank is 1.00. Adjust the values in-between for each setting, and presumably it's Ahead Slow you'll want to modify. It'll take a few attempts of trial and error, so maybe keep a backup of the original file or use JSGME.

That looks easy, I'll give it a try. Funny there is only one configuration that has to do for both kinds of engines but I can live with it. Thanks!

it's entirely a matter of taste, but I've personally changed Ahead Standard to a value way less than 0.80, and I highly recommend it. To me, Standard is used for "fast cruise," whereas 1/3rd is for "efficient cruise," that way Standard gives us 11-13 knots depending on the type of boat, instead of the ~15 it usually gives. The way I see it, it's rare enough to want 15kt that you can just manually order that speed, since Full Ahead gives us only a little more at 16-18kt depending on the type and conditions.

It's fun to hone these settings to your liking! Really makes you feel like the boat is yours. On some types I've tweaked Snorkel/Periscope depth to be a little shallower to make rough weather attacks easier.

Fwiw, think about trying to use the silent running feature sparingly anyway. It's very unrealistic by being to "powerful" and makes the boat virtually impossible to be detected. Of course, one can play the game as they wish too.