Why do the brakes on the train “squeal” at times?

The squealing of the brakes is quite normal and is especially heard on downhill sections. This squealing is the result of a practice called “Minimum Brake Application.” This means that the driver applies a very light braking force to the entire train to allow fine control over the speed of the train, as well as allowing the train to be stopped rapidly and smoothly should their be a need to do so.