Brake Questions

[Saturnalia]

I am curious:

1. Does applying the main brake also apply the independant, or are the two totally seperate?
2. Does applying the emergancy brake also apply the independant brakes, or just the trainline?

[Mr. Tops]

When you apply the automatic brake (train brakes), the independent also sets up. You have to bail (actuate) the indepedent brake off if you don't want the engine brakes to set up. Generally speaking (UP way, anyhow) you set your automatic, then bail the independent, ie no engine brakes until you are coming to a stop. Same goes for when you go into emergency; brakes are applied on the engine(s) as well and you have to bail off the independent, releasing the brakes on the engines so you don't get sliding wheel (flats spots) or excessive slack run-in.

[JStryker722]

In other words,better the back of train be used for braking than the front( sorta)?

[Mr. Tops]

In other words,better the back of train be used for braking than the front( sorta)?

Well, just not the engines. If the rear half of the train is braking and the front half isn't, you may break things that aren't suppposed to break. It'd be like a slinky streching out and if there's a weak point, you'll find it. IE, a knuckle, drawbar...

The reason you bail off the independent brake to release the engine brakes (except when coming to a stop) is to prevent sliding wheels, which would create flat spots; and reduce the chances of excessive slack run-in, which could result in a derailment/track damage if severe enough. It also puts less wear and tear on the locomotive brake shoes, so they don't have to be replaced as often.

When a train goes into emergency, you bail off the engine brakes and also dump the air from the EOT. There is a toggle switch on the head-end box and when armed up to an EOT, one flip of said switch will put the entire train in emergency from the rear. This is to prevent both scenarios mentioned above; putting too much force on the train either way and pulling it apart or crunching it up and derailing.

[Saturnalia]

I know many local trains operate with flags instead of EOTs, is there a train length or speed at which EOTs are required?

[Mr. Tops]

I know many local trains operate with flags instead of EOTs, is there a train length or speed at which EOTs are required?

No length restriction but speed and tonnage are factors. I'm not certain of other railroads, but on UP, the only trains that can leave a terminal without an emergency-enabled EOT are locals and work trains, and even then they must be less that 4,000 trailing tons. Also, trains that do not exceed 30 mph do not have to have an emergency-enabled marker. That being said, an enroute failure of the emergency capability from the head-end "FR NOCOM" (front-rear no communication) restricts a train to 30 mph. At night, a train that doesn't require an EOT still needs a highly visible marker, be it an EOT or fusee. An EOT wouldn't need to be armed necessarily, but just hung and marker flashing, a red flag is not acceptable after dark.

[CSX_CO]

When you set the 'automatic' the train brakes will start setting from the point of application and approximately one car at a time. This is why you want the train either fully bunched or full stretched when you go to set the brakes for good train handling. I say 'point of application' because when running with DP, and no 'fence up', the rear DP unit will make a matching application of the brakes and will also set the brakes from the rear. That is why trains with DP will stop and 'go' faster, you're setting the brakes from both ends, and charging the train from both ends.

There is something called a 'bake pipe gradient' through the train. The locomotives are putting out 90 lbs of air, but by the rear of the train it has been reduced. Leaks, brake pipe length, etc play into this 'gradient'. Brakes set up because of a 'difference in pressure' between the brake pipe and the service portion of the brake reservoir. The engineer makes a reduction in the brake pipe, the triple valve responds by taking air out of the service portion and putting it into the brake cylinders. On a 'conventional' train the 'gradient' is a slope. On a DP train, it is a shallow 'v'.

On another thread they talked about 'pissing away the air'. To set the train brakes, air is taken from the 'service' portion of the brake reservoir of the car, and put into the brake cylinder, forcing the piston out. For this example, you take 10 lbs. Once you've slowed the train, you knock the air off. Air starts flowing to the brake pipe again, releasing the air out of the pistons, and starts filling the 'service' portion of the reservoir again. If you don't have time to fully charge the brake pipe, and you need to make another reduction, you have to take 3 more lbs of air then you did on the previous reduction.

If you take 10 lbs again, you'll probably get a few brakes to set up on the train, but you're not getting a uniform brake application through the train. A good engineer will note the brake pipe pressure on the HTD of the rear to get a general idea of when his trainline is 'fully charged'. Most of the class I's have "Air Flow Meters" which measures the amount of air going to the brake pipe. You need less than 60 cfm to be 'legal' in the FRA's eyes, but when fully charged its wise to see how much air is flowing into the pipe from the locomotive, again to know when the brake pipe is fully charged.

That is why when slowing the train, if you're immediately reaching for 20lbs of air or full service, you're bordering on out of control. Trust me, I've been there. Coming down Bellefountaine with a 14,000 ton train, right at 50, and getting an 'approach' for a train stopped at Ridgeway. I was already in full dynamic and first service to keep it at 50. Went full service and even used a liberal application of the "Flintstone Brake". I was complying with 'restricted speed' at 127 at the bottom as far as not 'speeding', but thankfully it was short train ahead. A little heads up from Indy to the fact a train was stopped at Ridgeway would have gone a long way there...

Just to overwhelm you, the cars also have an 'emergency' portion of the reservoir in addition to the 'service' portion. The 'emergency' portion is what keeps the brakes applied on a car when the car is in 'emergency' and no air is flowing to the system. Once the 'emergency' portion is drained (either by a leak or using the bleed rod) the brakes on the car will release. This is why railroads have rules about not relying on the 'air brakes' to hold a cut of cars, and why handbrakes must be applied. Eventually the brakes are going to release, and those cars will be 'free rolling'. This is what is confusing to a lot of 'young' railroaders. You need air to release the brakes, you need air pressure to set the brakes but no air in a car means the brakes are released. That Westinghouse guy was one smart cookie.

The reason you bail off the independent brake to release the engine brakes (except when coming to a stop) is to prevent sliding wheels, which would create flat spots; and reduce the chances of excessive slack run-in, which could result in a derailment/track damage if severe enough. It also puts less wear and tear on the locomotive brake shoes, so they don't have to be replaced as often.

"Bailing off" is more of a train handling thing, though wear and tear on the brakes does come into play. You're not going to flat spot the wheels with only 10 or 15 lbs of air set. Again, if you're having to use full service to stop for a signal or something (other than non-emergency) then you're bordering on 'out of control'. I liked using dynamics and about 10 lbs of air. You could then put a little more air on to stop quicker or use the dynamic brakes to slow. Plus at 10 lbs reduction, you could kick the brakes off without fear of sticking brakes because they didn't release. "First Service" is nice for conditioning brakes for a stop (getting ice and now off the rigging) or for starting to slow the train if you know you're going to bring it to a full stop. Once stopped, set the res equate 20 lbs of air and take a break.

However, dynamic brakes cut out once there is 10 lbs of air in the locomotive brake cylinders. You don't want to be in full dynamic, set 10 lbs of air to bring the train to a stop, and have your dynamics cut out. That's why you 'bail off' when in dynamic. When stretch braking, you 'bail off' so that the brakes aren't 'slowing' the engine while you're trying to keep it fully stretched out.

Using the automatic brake will give you a little additional pressure in the locomotive brake cylinders when you go to full service. This is helpful in yard switching service where you're not using air through the entire cut. Gives you a couple extra pounds of air to stop with, provided you don't actuate the air off out of habit. Also, the locomotive brakes can be set up so that using the automatic will not 'slide' the brakes. Conrail's SD38 and MT6 (and conceivably most of their yard service stuff) was set up such that it was nearly impossible to slide the brakes while using the independent or automatic brakes. I've actually run yard power around on a very snowy and cold morning with 10 lbs of 'automatic' set. This let me start to warm the brakes up in preparation for switching. This was the same morning where even throwing the engine in emergency wouldn't stop it. Thankfully the track leveled out and we could finally get stopped. This is something that will catch a lot of engineers off guard, especially 'new' ones. When the brakes are cold, they don't stop for anything. In my case, I was expecting the engine to have difficulty stopping, just wasn't expecting to not stop at all...

Practice Safe CSX

[CSXFanatic1001]

I always thought that the locomotive brake /or independent brake would be used manually, not with the main train brakes, but I have never actually been inside a US locomotive, so I don't know for sure myself???

[Trainman223]

When you set the 'automatic' the train brakes will start setting from the point of application and approximately one car at a time. This is why you want the train either fully bunched or full stretched when you go to set the brakes for good train handling. I say 'point of application' because when running with DP, and no 'fence up', the rear DP unit will make a matching application of the brakes and will also set the brakes from the rear. That is why trains with DP will stop and 'go' faster, you're setting the brakes from both ends, and charging the train from both ends.

There is something called a 'bake pipe gradient' through the train. The locomotives are putting out 90 lbs of air, but by the rear of the train it has been reduced. Leaks, brake pipe length, etc play into this 'gradient'. Brakes set up because of a 'difference in pressure' between the brake pipe and the service portion of the brake reservoir. The engineer makes a reduction in the brake pipe, the triple valve responds by taking air out of the service portion and putting it into the brake cylinders. On a 'conventional' train the 'gradient' is a slope. On a DP train, it is a shallow 'v'.

On another thread they talked about 'pissing away the air'. To set the train brakes, air is taken from the 'service' portion of the brake reservoir of the car, and put into the brake cylinder, forcing the piston out. For this example, you take 10 lbs. Once you've slowed the train, you knock the air off. Air starts flowing to the brake pipe again, releasing the air out of the pistons, and starts filling the 'service' portion of the reservoir again. If you don't have time to fully charge the brake pipe, and you need to make another reduction, you have to take 3 more lbs of air then you did on the previous reduction.

If you take 10 lbs again, you'll probably get a few brakes to set up on the train, but you're not getting a uniform brake application through the train. A good engineer will note the brake pipe pressure on the HTD of the rear to get a general idea of when his trainline is 'fully charged'. Most of the class I's have "Air Flow Meters" which measures the amount of air going to the brake pipe. You need less than 60 cfm to be 'legal' in the FRA's eyes, but when fully charged its wise to see how much air is flowing into the pipe from the locomotive, again to know when the brake pipe is fully charged.

That is why when slowing the train, if you're immediately reaching for 20lbs of air or full service, you're bordering on out of control. Trust me, I've been there. Coming down Bellefountaine with a 14,000 ton train, right at 50, and getting an 'approach' for a train stopped at Ridgeway. I was already in full dynamic and first service to keep it at 50. Went full service and even used a liberal application of the "Flintstone Brake". I was complying with 'restricted speed' at 127 at the bottom as far as not 'speeding', but thankfully it was short train ahead. A little heads up from Indy to the fact a train was stopped at Ridgeway would have gone a long way there...

Just to overwhelm you, the cars also have an 'emergency' portion of the reservoir in addition to the 'service' portion. The 'emergency' portion is what keeps the brakes applied on a car when the car is in 'emergency' and no air is flowing to the system. Once the 'emergency' portion is drained (either by a leak or using the bleed rod) the brakes on the car will release. This is why railroads have rules about not relying on the 'air brakes' to hold a cut of cars, and why handbrakes must be applied. Eventually the brakes are going to release, and those cars will be 'free rolling'. This is what is confusing to a lot of 'young' railroaders. You need air to release the brakes, you need air pressure to set the brakes but no air in a car means the brakes are released. That Westinghouse guy was one smart cookie.

The reason you bail off the independent brake to release the engine brakes (except when coming to a stop) is to prevent sliding wheels, which would create flat spots; and reduce the chances of excessive slack run-in, which could result in a derailment/track damage if severe enough. It also puts less wear and tear on the locomotive brake shoes, so they don't have to be replaced as often.

"Bailing off" is more of a train handling thing, though wear and tear on the brakes does come into play. You're not going to flat spot the wheels with only 10 or 15 lbs of air set. Again, if you're having to use full service to stop for a signal or something (other than non-emergency) then you're bordering on 'out of control'. I liked using dynamics and about 10 lbs of air. You could then put a little more air on to stop quicker or use the dynamic brakes to slow. Plus at 10 lbs reduction, you could kick the brakes off without fear of sticking brakes because they didn't release. "First Service" is nice for conditioning brakes for a stop (getting ice and now off the rigging) or for starting to slow the train if you know you're going to bring it to a full stop. Once stopped, set the res equate 20 lbs of air and take a break.

However, dynamic brakes cut out once there is 10 lbs of air in the locomotive brake cylinders. You don't want to be in full dynamic, set 10 lbs of air to bring the train to a stop, and have your dynamics cut out. That's why you 'bail off' when in dynamic. When stretch braking, you 'bail off' so that the brakes aren't 'slowing' the engine while you're trying to keep it fully stretched out.

Using the automatic brake will give you a little additional pressure in the locomotive brake cylinders when you go to full service. This is helpful in yard switching service where you're not using air through the entire cut. Gives you a couple extra pounds of air to stop with, provided you don't actuate the air off out of habit. Also, the locomotive brakes can be set up so that using the automatic will not 'slide' the brakes. Conrail's SD38 and MT6 (and conceivably most of their yard service stuff) was set up such that it was nearly impossible to slide the brakes while using the independent or automatic brakes. I've actually run yard power around on a very snowy and cold morning with 10 lbs of 'automatic' set. This let me start to warm the brakes up in preparation for switching. This was the same morning where even throwing the engine in emergency wouldn't stop it. Thankfully the track leveled out and we could finally get stopped. This is something that will catch a lot of engineers off guard, especially 'new' ones. When the brakes are cold, they don't stop for anything. In my case, I was expecting the engine to have difficulty stopping, just wasn't expecting to not stop at all...

Practice Safe CSX

That explains sooooooo much stuff!!!!!!

[SD80MAC]

I always thought that the locomotive brake /or independent brake would be used manually, not with the main train brakes, but I have never actually been inside a US locomotive, so I don't know for sure myself???

You can use the independent brake manually, to stop only the engine/engines if you're running light or whatever. But the independent will also apply when the automatic brake is applied, unless it's bailed off, as everyone else said.

[CAT345C]

To add to the bit about EOTsI believe the GCOR rule states anything over 40mph, work trains or any trains traveling on a heavy grade over a certain length need an EOT. There are two way and one way EOTs. One ways will just relay brake pipe pressure at the rear. Two way will allow you to place the train into emergency if the device is armed correctly.
CSX_CO's post covers this pretty well.

Also over the course of the last year I have had several different people from 3 different railroads state the FRA does not recognize any thing other than EOT as a flashing end of train device. The magnetic lights or lights on a stick are not considered legal I guess. I've never been in a situation where j had to worry about that, we always have a EOT with us.

Finally glad to see some good questions on here as late.

[Mr. Tops]

To add to the bit about EOTsI believe the GCOR rule states anything over 40mph, work trains or any trains traveling on a heavy grade over a certain length need an EOT. There are two way and one way EOTs. One ways will just relay brake pipe pressure at the rear. Two way will allow you to place the train into emergency if the device is armed correctly.
CSX_CO's post covers this pretty well.

Also over the course of the last year I have had several different people from 3 different railroads state the FRA does not recognize any thing other than EOT as a flashing end of train device. The magnetic lights or lights on a stick are not considered legal I guess. I've never been in a situation where j had to worry about that, we always have a EOT with us.

GCOR does not state anything about speed/tonnage and the loss of two-way communication. That is found in each individual railroad's air brake & train handling rules. The only thing the GCOR says about EOTs is basically what constitutes a marker and when it must be displayed.

GCOR says a high visibility marker (EOT) or dim headlight (DPU or light power) will be displayed from 1 hour before sunset to 1 hour after sunrise or in adverse weather conditions when visibility is restricted to less than a half mile. Alternative markers may be used when a HVM is not required (during the daylight hours). Acceptable alternative markers are a reflector, red flag or light fixture. These can also be used at night in the event of a HVM failure.

UP's ABTH rules state that must be operated with the ability to place the train in emergency from the rear (read, they must have a 2-way EOT). The following trains however, are exempt from this rule: trains that will not operate over 30 mph and do not operate on heavy/mountain grades, locals/road switchers/work trains not operating on heavy/mountain grade and not exceeding 4,000 trailing tons, light engine consists fewer than 8 engines, passenger/commuter trains. So, these trains can leave town with a red flag, if they meet the criteria. They need to have an EOT an hour before sunset though. It doesn't need to be armed/two-way capability, they just need it for the HVM purposes.

[Saturnalia]

I remember hearing over a year ago something about an EOT missing/not working on an E949 out of West Olive, and that they needed someone to confirm the rearmost car, IIRC to proceed at track speed? What are the limitations if an EOT fails or whatever happened here?

[CSX_CO]

I remember hearing over a year ago something about an EOT missing/not working on an E949 out of West Olive, and that they needed someone to confirm the rearmost car, IIRC to proceed at track speed? What are the limitations if an EOT fails or whatever happened here?

EOT fails (there are several things that constitute a failure) enroute, then you are restricted to 30 mph until the EOT can be changed out or communication is restored. Front to Rear no communication is a 'failure', rear to front is not. Valve fail, dead batteries, radio break, etc. are all enroute failures. Trains are not allowed to leave their initial terminal without functioning two way telemetry unless otherwise provided by the rules.

I don't know what the exact situation you are referring to, but it sounds to me that the E949 needed someone to verify their rear car to ensure they were clear of some form of dark territory. To 'clear' an authority you can use the pressure reading of the EOT and the odometer feature of the HTD. If the EOT fails, you either have to have the rear car number verified, with marker in place, or use the reading of an HBD/DED with axle readout that matches the known count for the train. If the odometer feature is in operative, then you cannot clear your authority until you've proceeded 3 miles past the end point of the authority.

[A No.1]

As far as an Automatic Brake application, The ABD and ABDW (All Newer) Control Valves have an Accelerated Service Application feature. This is accessed by taking a Minimum (6 to 8Lb.) brake. It only takes 1 to 1&1/2Lbs. to propagate. The Accelerated service Application feature takes a 4 to 6Lb. "bite" of air out of the Brake Pipe Locally at each car. This Propagates a more uniform and speedy brake application through the entire train.

Accelerated service Release is another feature of the ABD and ABDW valves that is accessed with a Split Reduction, Minimum then 10Lb reduction. This feature uses air from the Emergency Reservoir on Each car to help Recharge the Brake pipe when the Automatic is moved to Release and Brake Pipe pressure begins to Increase. This Allows for a Quicker and more uniform release of the brakes.

This is why we use Split Reductions of the automatic. First a Minimum then 10Lbs. (During One Brake Application)

Remember, The Brakes will Release on ALL the cars when the Brake Pipe Pressure rises above Auxiliary Reservoir Pressure on Just ONE car. When a Brake is set The Engineer should monitor the EOT for a Rise in Brake Pipe pressure indicating an Unintentional Release of the Brakes.




These new Control Valve features are what allows these LONG and Heavy trains to be handled safely.

[CSX_CO]

This is why we use Split Reductions of the automatic. First a Minimum then 10Lbs.

That depends on your intended goal. When using the air to 'stop' then a minimum is a good idea, followed by additional reductions to bring you to a stop where you intend to. When stretch braking, or using air and dynamics, it is a good idea to go right to 10 lbs reduction so that if you need to release the brakes, you'll achieve a full release throughout the train should you need to release the brakes.

When 'stretch braking' or using the dynamics, if my intended goal was to slow, but not stop, I always reached for 10 lbs right away for that very reason. Conductors get cranky if they have to walk the train because of sticking brakes. Only when slowing for a known stop did I ever set the minimum to condition the brakes. Otherwise, if the dispatcher wakes up, you're going to need to make an additional reduction before kicking the brakes off if the signal suddenly clears.

I suppose with the CN and their land barges the minimum service you recommend would make sense. At least on CSX we have train limits.

Practice Safe CSX

[A No.1]

This is where the Book and what happens in practice part ways. In order to gain a fast and uniform rolling release as in stretch braking, You really want the split reduction to gain access to the Accelerated Service Release feature.


Do most people go straight to 10lbs? Yes they do. The book does not want you to. Because it will take longer for the brakes to release and they will release from front to back as the pressure comes up. A split reduction will give you a more uniform and speedy release. Better with the Dynamic or Stretch. Any way, that's how the ABDW control valves are designed.

Please note, I did not say release the Minimum. I think this is what you were getting at with the sticky brake thing.
A good 10lb set achieved through a split reduction is what the book is after.

Yeah, I was NOT refering to "Going Deeper" on a Second Application.

[BnOEngr]

I always try to get the rear end to drop at least 10# before I try to release, especially on long trains or autorack trains.

Another issue with the quick release using emergency reservoir air is that if you re-apply and release the brakes a couple more times, this results in the "pissing away the air" issue. The emergency reservoir becomes depleted if insufficient time is allowed for recharge of the system, and dumping the air to try and stop will not be as effective as with a fully charged brake system.

[A No.1]

Every time you have to Cycle brake you Are "Pissing Away the Air". And really as long as you let a Minimum set up good meaning Don't kick it off too soon, You shouldn't get sticky brakes anyway. Winter is a different story.

A cool trick I was thought for maintaining a certain speed say on a down grade, Set a Minimum, Let it set up, Kick it off, Count to 10, Set another Minimum, You get just enough brake to hold a constant speed. Really cool actually. In certain situations anyway. None of this crap can really be Black and White. Its all situational.

Be ONE with the Train Luke. Use the Force.

BTW, I Hate Dynamic Brakes.
LoL

[A No.1]

DP RULES