Suppression and Handle Off

[FHRob]

What do the train brake settings suppression and handle off mean, and when is each used?

Rob

[BNSFdude]

Full Service/Suppression is a point on the brake valve that reaches equalization balance of the BP and BC (64.7PSI in a 90PSI brake environment)
It is also where you will position your handle to reset a penalty (full service) application such as one initiated by a safety appliance (Alerter, PTC, cab signals).

Continuous Service/Handle Off is where you position your brake controller to put a unit in the "trail" position with the cut in valve on the brake stand. It will draw down the EQ res and transversely the BP to 0 PSI at a service rate. Aside from being the position for trailing units brake stands, it is also used in the winter or in a yard where a train is to be inspected to draw the trains BP down to 0 prior to cutting away as to avoid initiating an emergency application.

[FHRob]

In regard to Handle Off, could you explain the meaning of "It will draw down the EQ res and transversely the BP to 0 PSI at a service rate."?

Rob

[BNSFdude]

A service rate is a normal brake application speed.

Rather than blowing it all out quickly as an Emergency Application does.

I don't remember the numbers for the service application rate off the top of my head.