Originally Posted by desirableroasted

Actually, you want to set your RPMs to 80rpms or under (some say 75).

Go up in the conning tower, where you will find two identical dials. If you are at 2 knots, they will be pointing at around 100.

Ease your speed down until they read no more than 80. Then you are at silent running.

Also, it is a good thing to rig for silent running even if you aren't doing repairs or loading. Principally, because the minute you do get damaged, the compartment crew will try to fix the damage, even if you have not assigned your special repair team to the compartment.