Is your feature request related to a problem? Please describe.
My server is suffering from frequent block lag and I am seeing messages about skipping ticks. I also am seeing the saving trains message at least once per minute, and I suspect this is related. This is linked to #1668 but not the phantom train issue.

Describe the solution you'd like
A config setting for the frequency of saving trains. I'd like to get down to every 10-15 minutes, like the save-all script I have running.

Describe alternatives you've considered
A flat decrease in train saving frequency would also work, but I'm not sure if that would cause it's own issues for some users.

The reason I suspected that the Saving trains was the issue is that I would have a solid 20 TPS from tickprofiler, but still get lag and messages about skipping ticks. Now, as far as the server autosave, I have the server running save-all every 30 minutes, but as I said the saving trains message appears every minute. I searched the minecraft wiki and elsewhere for more information, but I could not find another reference to autosave frequency.

afaik they are not related. you need a profiler result like a spark one to confirm that the issue is actually caused by trains saving.

moreover, train saving is bound to server autosave, which you can already configure. a custom lower saving rate from railcraft will lead to errors

Moving to #1751. Trains are saved as frequent as vanilla maps, so things are fine.