[Traindude]

It's a fact that brake pipe pressures are higher for passenger trains than for freight trains. However, you may encounter photos of what appear to be Amtrak passenger trains with what appear to be one of the host railroad's own (otherwise freight-only) locomotives in the lead. You're probably wondering how the leading freight locomotive is able to release the brakes of the passenger cars with the lower pipe pressure associated with freight trains. It doesn't.

In the real world, whenever motive power substitutions like this occur, locomotives' brake systems can be adjusted to raise or lower the maximum brake pipe pressure as needed. In the "old days", this was accomplished by the brake system's feed valves. Adjusting the valves would make the maximum regulated pressure in the brake pipe and EQ reservoir higher or lower when needed. On modern locomotives with computerized controls, these adjustments can be made by the locomotive's on-board computer.

To this day, the only way to allow this kind of flexibility in MSTS/OR was to have TWO separate .eng files for each locomotive--one with brakes configured for freight service and the other for passenger.

The ability to adjust the maximum brake-pipe pressure in-game could potentially eliminate the need for two .eng files for the same locomotive.