Safety and brakes questions

[Passenger]

Train brake failure; broken valve
Risks Digest
Association for Computing Machinery (of which I am a member)

During a switching movement at a siding, a locomotive's automatic brake
valve handle suddenly has no effect. Engineer applied independent brakes,
but they can't stop the train due to its weight.

[Broken valve roll pin]

Releasing the deadman pedal was no help because the brake system was
designed to ignore it if the locomotive brake cylinders had at least 30
PSI. There was no other means in the cab to exhaust the train line.

...

Are there ways to prevent this? Perhaps aready in use in the USA?

[amtrakhogger]

All locomotives in the US have a fireman's side emergency brake valve (Big Red) which directly vents the brake pipe and could be activated to stop the train in the event of a scenario such as this one.

[RearOfSignal]

Interesting, perhaps the FRA would regulate a dump valve separate from the brake stand on the engineer's side in the cab, to prevent this.

[DutchRailnut]

Its already incorporated in each locomotive with 26 type braking, the dump feature works no matter if brakestand is cut in or cut out.
The locomotive in the example above still had a schedule 14 brake.

[BR&P]

The locomotive in the example above still had a schedule 14 brake

No, the photo shows the loco had 26 brake schedule. #14 looks entirely different.

While it was an EMD switcher, it was in the UK and had at least some modifications. It is not mentioned, but had the loco had a fireman's side emergency brake valve it probably would have been used. Note also it is at least partially crew error - while the problem was initially caused by a broken pin, the engineer applied the independent in an effort to stop - quite logically. However it says that if he had released the independent and also kept his foot off the deadman's pedal, the train brakes would have applied. A lack of proper training, perhaps?

The availability of emergency application even when cut out is not solely on 26 brakes - I know it is that way on 24, and believe even 6 and 14 schedules have that function.

[Jtgshu]

The locomotive in the example above still had a schedule 14 brake

No, the photo shows the loco had 26 brake schedule. #14 looks entirely different.

While it was an EMD switcher, it was in the UK and had at least some modifications. It is not mentioned, but had the loco had a fireman's side emergency brake valve it probably would have been used. Note also it is at least partially crew error - while the problem was initially caused by a broken pin, the engineer applied the independent in an effort to stop - quite logically. However it says that if he had released the independent and also kept his foot off the deadman's pedal, the train brakes would have applied. A lack of proper training, perhaps?

The availability of emergency application even when cut out is not solely on 26 brakes - I know it is that way on 24, and believe even 6 and 14 schedules have that function.

It might depend on how instant the deadman pedal "reaction" is - does it produce a whistle for a few seconds before putting the train in the hole? Or is it instant? A few seconds release of the independent to wait for the deadman to kick on I imagine would be so hard to do for the engineer to just sit there and wait! Not to mention, the train would have accelorated even more with the brakes totally released. Even though only the independent was on, it was helping a little bit

Im surprised there was no mention of "plugging the motors" unless he did, as it looked like the throttle was in Notch 2 in the pic (or at least the little window showed a "2". Plugging the motors for those who don't know is when you put the reverser in the opposite direction of travel, and pull for power. Just like putting your car in forward or reverse before stopping - lots of noises and usually a pretty sudden and violent stop of the car.

However, you can't plug the motors if the train is in emergency. Putting the train in emergency gives up all control of the train by the engineer - I mean in this instance it would have probably helped, as the train line airbrakes im assuming were connected, but there have been several accidents/runaways that weren't stopped by putting the train in emergency. Sure they are usually on mountain passes and steep downgrades, but still. Also if there is a blockage in the brake pipe or there aren't that many cars hooked up to brakepipe or whatever, plugging the motors and NOT going into emergency MIGHT be a better course of action. You can plug the motors THEN if that don't work, you can dump it, but you can't dump it and then plug the motors, as the loco would need to reset to be able to draw for traction power.

The trian could also be put in emergency by reaching down and opening the angle cock on the front of the loco. While it really is a last resort kinda thing, on the way to jumping off, reach down and open the brake pipe (if able to be reached from the porch, of course) - that will dump the train as well

[BR&P]

The only problem is that because of the damage it does to the locomotives, plugging the motors is a last resort. I've never done it, but there are many times when I've dumped the air. The "natural progression" of things you try leaves plugging the motors until last.

That said, there would still be some value in plugging them. Even in emergency, a locomotive can still develop first notch power. I believe this is so it could be moved away from a fire or some other situation. So even with PCS tripped it would develop some amount of retarding effort. Whether that would have been of any help in this case I have no idea.

[GOLDEN-ARM]

The "deadman" pedal has no bearing on this. With sufficient BCP on the loco, it becomes "over-ridden", and is of no use. IF it had been in use, it still won't produce the emergency application you mentioned. The deadman produces a "penalty" application, and that reduction is made to the trainlined brakepipe, at a service rate of reduction. As it reduces steadily, it bypasses the "minimum reduction" position, thus negating the "quick-service" feature found on modern AB valves, on the freight cars. This means, even slower stopping times, over a controlled split reduction, or an emergency application. The automatic brake valves do blow into emergency, when the handle is moved to that position, not just on the 26 valve, like some nut above, has mentioned.

Not sure what caused the automatic to "suddenly have no effect", but with another valve (the EBV) located less than 5 feet away, from the engineers automatic brake valve, literally 2 steps can be taken, and the valve reached, and opened. If the independent wasn't sufficient to control the movement, it seems that there might have been an opportunity before this, to apply some handbrakes, or air-up some cars first, if they were switching without air. [quote=]Risks? First, not having a second, independent emergency valve. Second,
the override on the deadman almost lead to dead men.....[/quote] This is misleading, and erroneous, in the USA, anyways. There are 2 EBV's located in the control compartment of modern locomotives. They are mandated to be there, by law, for use by crewman other than engineer, in case of emergency. Second, the deadman works exactly as it is intended to work. It applies the brakes to a train, or locomotive, while moving, if the engineer becomes incapacitated. (easily over-ridden, these have been replaced by crew alertness devices) There's no need to stop a train, from a deadman, if the engineer has already fully applied the loco brakes. This is just histerical hype, from the agency hired, to review this incident, and reach a conclusion. (think "justification of the paycheck") If this system failed, due to a broken portion of the ABV handle, in the US there are means to overcome this. This happened in the UK. Who knows what they are doing over there?............