Pyromancer wrote:

Btw, what is the independent brake? We tend to have straight-air on
locos, and automatic air or automatic vacuum on the train.

North American locomotives have a dual braking system. The straight air
system is called the independent brake, since it can be applied
independently of the brake on the rest of the train. Locomotive brakes
will also apply with an automatic brake application.

In typical freight train operation, the driver will "bail off". or
release, the automatic brake application to reduce wheel heating. If
the driver is otherwise incapacitated, the brakes will apply. On
shorter trains, like passenger trains, the driver will typically bail
off the automatic application, then apply a partial application of the
independent, straight air brake to assist in reducing train speeds.