[derstosstrupp]

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”.