Emergency Braking

(3) Descending Grades. For slowing or stopping on descending grades, it may be

necessary to let the train bunch by reducing power before following the braking steps described

above for level terrain. After the service brake is released, it will be necessary to apply sufficient

independent brake to prevent adverse buff and draft forces (slack changes) as the service brakes

release.

c. Emergency Braking. Emergency braking occurs when the brake pipe is opened to the

atmosphere, resulting in the rapid reduction of brake pipe pressure to zero. This action is called

dumping or busting the air. A crew member shall only apply emergency braking when a stop must

be made as quickly as possible. Extremely high buff or draft forces will occur during emergency

braking.

Emergency braking occurs in three situations: when the engineer places the automatic brake into

the emergency position, when a crew member activates the auxiliary emergency brake valve, or

when a brake pipe or air hose separates.

When the emergency brakes have been applied due to a brake pipe or air hose separation, the

engineer shall immediately bail off (push down) the independent brake lever, place the automatic

brake valve in emergency position, and leave it in that position until the train stops. Most

locomotives will automatically dispense sand during emergency braking. If the locomotive does

not automatically dispense sand, use sand until the train stops. Place the throttle in idle.

After an emergency application has occurred for any reason, the crew shall not reset the brakes or

move the train until the train has been completely inspected by maintenance personnel and the

fault which caused the emergency application identified and corrected. After the train has been

inspected and any fault corrected, the automatic brake valve can be returned to the running

position to release the brakes.

Track inspectors shall inspect the track structure to determine if the emergency application

created track damage (shifting of track, kinking of rail or debris on the track).

d. Independent Braking. Stops with Independent (Locomotive) Brakes Only.

Independent braking should be avoided if possible. Independent braking should only be used at

extremely slow speeds with light loads or emergencies. Stops and slowdowns should be made

with the automatic brake when practicable. When only independent brakes are used to slow or

stop a train, very little pressure should be used until the train slack has closed in against the

locomotive or moved out if backup movement is being made. Independent brakes should be

controlled to prevent wheels from sliding and to prevent brake shoe damage. Independent brakes

alone should not be used to make stops and slowdowns when speed of the train is more than 15

mph.

Under normal conditions, the independent brake should only be applied when the throttle is in the

idle position.

The independent brake valve of the controlling unit of a multi-unit should be in at all times and the

handle should not be depressed and blocked in the release position.

3 - 41