Passenger Trains > FULL SERVICE Brake Application on Amtrak???

As a freight hogger who runs with a brake pipe pressure of 90 lbs., a 26 lb. brake pipe reduction is considered a FULL SERVICE brake pipe reduction. This is full braking effort. EMERGENCY just gets you there quicker, to a 26 lb. brake pipe reduction, which is full force braking (of course, after this is achieved, brake pipe pressure falls to zero, but you retain the same brake cylinder pressure, or pressure of the brakes against the wheels, or discs).

Now, though I have run the UPRR E-9's and the 6936 (UPRR uses 105 lbs. brake pipe pressure for passenger movements, whether with the steamers or with the Heritage Diesel Fleet units, unless it's a single business car movement on the rear of a freight, in which case you run at 90 lbs. with the rest of the freight train).

Have also run Amtrak F40's, and a Genny, and Amtrak uses 110 lbs. brake pipe pressure, if I recall correctly. However, I have never set more than a 20 lb. brake pipe reduction in one of my few cherished instances of running a passenger train, and this was a grand-standing stop with the E-9's. SO...I have to plead ignorance of what constitutes a FULL SERVICE brake pipe application at these higher brake pipe pressures. Is it still 26 lbs??? Or can you actually make a deeper brake pipe reduction with these higher pressures?

Bottom line Amtrak and commute hoggers: how many pounds constitutes a FULL SERVICE brake application in passenger service?

While we're at it, has Amtrak gone back to using graduated release and blended braking (2 characteristics that provide for much more versatile passenger train handling) now that the Mail and Express era is over? These two features were not used while Amtrak was hauling freight, because Amtrak chose the cheap route, and did not equip the newer MHC express cars with graduated release caps (although the original, older MHC cars which first came out DID have these features). I understood that it would have but cost $300.00 per car to fit them with the equipment needed for graduated release braking, and Amtrak chose not to do so, to the great displeasure of every Amtrak engineer I ever talked to, as they were stuck handling passenger trains with the direct release braking that is used by the most mundane manifest train. For those who do not know the difference, on a freight train, in direct release, you can make a 10 lb. reduction, and if you want more, you can go to 15 or 20 lbs., but, you cannot back off from 20 lbs. to a lighter 10 lb. reduction, you have to go back to full release. With graduated release, you can start out with a heavy 20 lb. reduction, then, when you've shaved off enough speed, feather it back to a lighter 10 lb. reduction...which makes for much more versatile train-handling with a passenger train.

For whatever reason, although the UPRR passenger car fleet is equipped for graduated release, they chose to run all their passenger movements in direct release. The only reason I can think of for this is that most freight hoggers are not familiar with graduated release, and so they simplify it by running everything set up for direct release.

Full Service is defined as when the Auxiliary Reservoir and the Brake Pipe equalize. Any further reduction of Brake Pipe pressure is a waste. A 26 PSI reduction from a Brake pipe pressure of 90 PSI results in a Full Service Application and achieves 64 PSI in the Brake Cylinder (64 + 26 = 90 PSI). A 32 PSI reduction from a Brake pipe pressure of 110 PSI results in a Full Service Application and achieves 78 PSI in the Brake Cylinder (78 + 32 = 110 PSI). Rule of thumb is for every 1 pound of Brake Pipe reduction the Brake cylinder pressure increases by 2 1/2 PSI until Equalization occurs. This is due to the volume relationship between the Auxiliary Reservoir and the Brake Cylinder (4 - 1). A reduction of 20 PSI from any Brake Pipe pressure of 70 PSI or greater will achieve a 50 PSI Brake Cylinder pressure.

Emergency from a Brake Pipe pressure of 90 PSI achieves 77 PSI in the Brake Cylinder. Emergency from a Brake Pipe pressure of 110 PSI achieves 93 PSI in the Brake Cylinder. An Emergency application of the Brakes achieves an increase of Brake Cylinder pressure of 20% above that obtainable with a Full Service application and at a much faster rate, Passenger build-up being faster than Freight due to length and weight of train.

Most of the time, to achieve a 32 PSI reduction with schedule 26C Brake equipment, you need to go to the Handle Off position to gain the added reduction as 26C Brake equipment will generally only reduce the Brake Pipe 26 PSI. There were some cams ground (and some 26 Brake stands so equipped) that would allow a 32 PSI reduction in the Full Service position of the brake valve handle, but they are largely gone since the RR's got out of the Passenger business.

In actual practice, more than a 26 PSI reduction is a waste of time (and air) because almost all 26C Service portions have their Service Limiting valves set between 59 - 64 PSI so you cannot achieve a true Full Service application on most Passenger cars when the Brake Pipe pressure carried is 90 PSI or above. Amtrak has the Superliners set even lower so as not to slide the wheels. I believe the Amfleet is still set for 64 PSI in Service and 99 PSI in Emergency. Amtrak changes their pressure settings from time to time, just about as often as the weather changes.

In regards to the 26C Control Valve, it is possible to achieve higher than normal Emergency application pressures (if the Emergency Pressure Limiting valves are incorrectly set) due to the fact that Amtrak uses a Main Reservoir line down the train that carries the same pressure as that in the Main Reservoirs on the Locomotives. This is generally 140 PSI. Because most Passenger cars use Relay Valves, the Control Valve actually only supplies a reference pressure to the pilot of the Relay Valve. The work of transferring air from the Supply Reservoirs to the Brake Cylinders on the cars is done by the Relay Valve and is a duplication of the reference pressure it sees from the Control Valve. Most Amtrak cars are equipped with differential Relay Valves, which lower the output to the Brake Cylinders by a certain percentage.

It's strange that UP runs a 105 PSI Brake Pipe pressure on their Passenger fleet. Five PSI more Brake Pipe pressure would not make much of a difference at the Brake Cylinders. I suspect the reason has more to do with the cut-in of the compressor governor than anything else.

As far as Amtrak's not having Graduated Release with the newer material handling cars, a proposal was made to Amtrak several years ago that would have given them Graduated Release on a train of 40+ cars, along with other valuable new features incorporated with the 26C Control Valve (that were not included in the original design), but Amtrak management at the time opted not to even view the proposal. It was a fairly inexpensive fix and would have greatly improved the handling of Amtrak trains. As an example, how would you hoggers like to have seen the Brake Pipe pressure at the last car of the train increase to within 5 PSI of the of the Brake Pipe pressure when the reduction was started, within approximately 3 - 4 seconds after the Brake Valve handle was moved to the Release position on a 40+ car train, after a Full Service Application (84 PSI)? It's a shame Amtrak never considered the proposal.

Did the proposal made to Amtrak make use of some type of two-way EOT?

Well,
I guess I owe Steve Lee an apology. I just figured the [little bit of] slack action experienced on UP excursions was to save money on brake shoes <G>.

RailNet802, out

Full service is 32lbs, on Caltrain (we follow the AMT-5, and have modified special instructions for air brake rules applicable to commuter ops) we run direct release with EP hold on the stainless galleries, and graduated on the MP36's and Bombardiers. It is my understanding that as the mail and express was gradually phased out, each train that was set up for direct release, was switched back to graduated. Per the AMT-5 air brake rules, you are allowed to run no more than two cars in graduated release, when the train is set up for direct release. When initiating an emergency brake application, it is recommended that you do not bail the engine brakes until the need for full braking effort is no longer there. Recommended braking is blended, I believe it's on 10 cars or less, IIRC.

VPayne Wrote:
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> Did the proposal made to Amtrak make use of some
> type of two-way EOT?

No. Valve was all mechanical. Proposal was also made though for ECP but Amtrak showed the same attitude.

fjc Wrote:
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> It is my understanding that as the
> mail and express was gradually phased out, each
> train that was set up for direct release, was
> switched back to graduated.

Frank, I recently rode #3 & 4 between Kansas and Colorado and all the engineers were not braking the train in Graduated but instead ran it like a Freight train. Handling was rough.

> Per the AMT-5 air brake rules, you are allowed to run no more > than two cars in graduated release, when the train is set up > for direct release.

This is because 26C Control Valves can become "confused" if they are set for Graduated Release and then operated in a Direct Release train. Generally a minimum application of about 10 pounds will be left on the cars which are in Graduated Release and you effectively have a stuck brake on those cars.

I thought the rule was on a train with mostly graduated release equipment,direct release equipment had to operate on the rear and you operated the train as if all the equipment was direct release.I thought it was a Federal rule.

I rode back in Jan 03' when M&E was still being handled, it was a long heavy train, some engineers were smooth as silk and others it was like they were driving a dump truck.


airbrake Wrote:
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>
> Frank, I recently rode #3 & 4 between Kansas
> and Colorado and all the engineers were not
> braking the train in Graduated but instead ran it
> like a Freight train. Handling was rough.
>

fjc Wrote:
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> I rode back in Jan 03' when M&E was still
> being handled, it was a long heavy train, some
> engineers were smooth as silk and others it was
> like they were driving a dump truck.

I rode this February and there were only two bags, coach/dorm, two sleepers, diner, lounge and two coaches. All handling was, as you nicely described it, like a dump truck. I never noticed anyone use graduated release. Could be that the valves were not set that way as when they released a few times in the stations the coach I was on did not sound as if it was in Graduated.

There were three engines on #4 though and that made for a very interesting time leaving the station. You could almost fell as if you were being pushed back in your seat when we would leave each station. Brought back memories of Bart.

A good hoghead (as opposed to a mere "engine driver"), could handle such a consist smoothly even if it was in direct, rather than graduated release. However, graduated release does make it easier to run a smooth train, from what I've heard. Whoever handled such a small consist roughly undoubtedly did not know the fine points of power braking, which is an art form in both freight and passenger service.

I appreciate the replies about the 32 lbs. being full service at 110 lbs. brake pipe pressure.

Red Wrote:
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> Whoever handled such a small consist
> roughly undoubtedly did not know the fine points
> of power braking, which is an art form in both
> freight and passenger service.

I agree with you on this point (and Frank's assessment of some railroaders) but from what I hear most Freight RR's do not allow the use of power braking. The RR's in this country have stopped all training on the art of braking as it used to be. When was the last time a RR had a Superintendent of Air Brakes? I am pretty sure they got rid of all of them. Yes, they have someone who may attend the Brake Committee meetings and make decisions on which type of equipment is to be approved or rule changes as far as air brakes are concerned, but there are no Superintendents of Air Brakes anymore and thus not much in the way of training - and just when trains are again getting heavier and trying to run faster. Air brake systems are growing more complex also.

You are correct...........most Class Ones do nto advocate the use of "power braking" on freights,instead concentrating on the dynamic brakes to slow and stop the train. This is not always the case,as I have stopped heavy freights with the air and left the dynamics alone. there is an art to running a train with air,and in hog back country,can be a life saver.
I learned how to run trains from hoggers who power braked with steam and early diesel consists not equipped with dynamic brakes. My rationale was to keep 'er stretched with the air,work the power down as needed,and stop smooth as glass. I grew up in a railroad family and train handling was a part of the conversation many a time.
These lessons from youth stuck with me to adulthood and when I have taught engineers I have always tred to impart air knowledge was just as important as dynamic braking,in fact more so. Class Ones are concerned that power braking increases wheel wear and fuel usage,as well as brake shoe wear. I can buy the part about wheel and shoe wear,but a watste of fuel?