Picking up individually spotted cars - air brakes

While moving some cars around my layout the other day, I ran into an interesting situation that I don’t quite know how to handle. At Agrawal Paper in Enfield, there’s three loading doors and a grate for woodchip unloading. They are spaced so that in most cases the cars are about 10 scale feet apart, not coupled. This allows space for cars with cushioned underframes.

(Yes, I realize the woodchip hopper is still loaded…I placed it there for the photo and forgot to remove the load)

Then I wondered how I would switch this industry. Spotting cars is easy enough, but how would a real railroad pick up cars? Assuming the cars are spotted with the trainlines empty and the handbrakes set, how long would it take to pump up and release the brakes in just one car? Would the local stop to release the airbrakes on each car (obviously they’d take off the handbrake before moving) or would they just shove it with the brakes applied and release the brakes on all of them at once? I assume it’s the former, but that would take so long…have the real railroads found a faster solution?

A railcar with the air completely bled off will roll freely, which has to be done at hump yards. For spotting single cars, the hand brake would be released and the car moved to where it is wanted, spotted and the hand brake reset, just using the locomotives brakes alone.

Doug

I’m assuming that they would just use the handbrake wheels to release the brakes and then move the cars as needed. I don’t think you need air to release the brakes as there are industries where cars are spotted in real life where the cars are moved by cables, and non-railroad vehicles (like front end loaders) where an air supply is not readily available.

Maybe one of our real railroaders can give you a more precise/correct answer.

-George

Wait a minute here! I have always been told that a trains brakesystem is controlled by negative pressure. It´s when the airpressure drops that the Train brakes and not when it is raised.

The reason why there is a delay while the air-compressors work up the air-pressure before a Train departs, is that it can´t move with an pressure lower than 350 Kpa (I believe it was?), I do know that railway cars have an override valve to be used in switching etc.

So what gives, now I dont know…

They would switch the entire track, no air applied, applying and releasing handbrakes as required. Then when they brought the outbounds back to their train, they would couple the air hoses, charge the trainline and make a brake test.

So if they were going to pick up all three cars and spot 3 new cars, one way to do it would be to come off the train with all three spotters (with air) and shove into the spur.

Couple into the first pull, release the handbrake.

Couple into the 2nd pull, release the handbrake.

Couple into the 3rd pull, release the handbrake.

Pull all 3 houtbounds and couple them to thier train. Set handbrakes as required.

Go back to the spur and spot the 3rd car. Set a handbrake on the 3rd car, turn the angle cock on the 2nd car. Uncouple from the 3rd car.

Spot the 1st car. Set a handbrake on the 1st car, turn the angle cock on the engine. Uncouple from the 2nd car.

Spot the 2nd car. Set a handbrake on the 2nd car, turn the angle cock on the 1st car. Uncouple from the 1st car and go back to the train.

Couple into the train, lace the air on the 3 cars picked up, make a b

That was my understanding too. That and when you use the handbrake wheel, you are actually manually releasing the brakes, not applying them.

-George

Are we pulling all the cars? Some of the cars? Do we need to respot anything?

If switching and respotting cars, I’ll often leave the brakes applied. No sense setting and releasing the brake 6 times.

Three cars…forget bleeding the cars off…release the handbrakes as you shove solid…then work the hoses on your way back to the engine.

When pulling everything, I usually make the hoses as I shove solid, ride the rear out, and do the brake test as I walk up to the motor.

Nick

We would pick all the cars up and connect the air hoses and check the bleeder valve and airline valves and then make our move using the locomotive brake…After we coupled onto our train we would cut the air in and then pump up the needed air…If we was making setouts then like Dave said we would use that air for braking.

A caution about assuming the handbrake is set…A lot of times the handbrake would be release…You see if a car puller or forklift was used to respot the car there is no guarantee the handbrake will be set…Never forget to check around the wheels for chocks…

Thanks for the answers everyone. I thought I had read somewhere that the air brakes are released when the air is totally bled out. I’ll take that into consideration while switching. I assume yard (flat switching) operations are roughly the same? (Mostly handbrakes and locomotive brakes except I assume with long cuts of cars)

Graffen, you are partially correct. A drop in air pressure tells the triple valve to apply air pressure to the brake cylinders. It is a bit confusing and complicated in its simplicity… There has to be pressure in the tanks to make the system work. Also you DO set the hand brakes. I work as a Trainman on the R&GV Museum RR. When I set the hand brake, turning the brake wheel manually sets the brakes. When I release the hand brakes, the cable is slack. Springs hold the brakes off not on. On the air brakes, there are 2 tanks that are charged with air. Emergency mode (Had that happen a couple weeks back…) uses a separate tank to hold the brakes on. Over time the pressure tends to bleed off, so hand brakes need to be set or the car has to be chocked if left standing for any length of time.

More than you need to know here: http://www.railroad.net/articles/railfanning/airbrakes/index.php Google “Triple Valve” and you will get lots of info.

Oh phooey. Do it the easy way; pick up the outbounds with your hand, set them on the main. Put the inbounds in their place. Back up train to pick up outbounds. [:D]

When I worked for the NS, in that situation we would couple on to the first car, lace up the air hose, make sure the air valve at the other end was closed and release the hand brake, then shove back to the next car and do the same thing, then the same thing for the 3rd car and so on till we had the whole track coupled up and air run thru the whole string. At that point you would perform a set and release air brake test, walking the length of cars for both the set and release to make sure all air brakes work and all hand brakes are fully released. Then you can pull the string out and set it either on the main, coupled up to the rest of your train or on another track. The actual leg work of air tests, lacing up air hoses ect is what eats up your time when you switching large industries with a road freight or local freight. Many modelers do not leave enough time for all this to happen when they are operating thier layouts. It takes time to pump up air pressure in a long string of cars, time for the conductor to walk the air test, make sure the EOT is function properly ect. If you ever get a chance to pick up a rule book and timetable for your modeled railroad and era, do so. It will be very good reading material and helping you operate much closer to what the prototypes do. You will always have differances between railroads in how the book says its to be done and how each crew actualy does the work, this can vary even more if there are supervisors watching ect LOL! Cheers Mike

Mike,I see they change things since I was a brakeman…It was normal to connect the air hoses and use the engine brakes(unless it was a large cut) and proceed back to our train cut in the air and pump from there…This save time…Now if we had setouts we would do the require work using the setout brakes as well as the engine brake doing the switching moves.

Actually supervisors didn’t worry us as much aft

Actually, I think we do. Consder that staion stops ( ifgure 10-15min prototype based on the ITM schedule I use) are cut down two a minute or two ( 1/8th the original time) a train inspection takes less than that (anything that takes longer is likely too long a train to do a lot of swiitching out) a 10second pause does nicely.

This oughta whet the appetite, this is an outdated rulebook that many many roads agreed on, and then tweek to their needs. This includes Class 1s all the way to Museums, but of note, NS is not one that adopted this rulebook, escept on the Conrail portions they inheirited.

http://www.sdrm.org/faqs/rulebook/toc.html

Indiana Transportation Museum uses the 4th ed., they just rolled out the 6th.

Ty: You asked about pumping the brakes. If the switch engine’s resovior is charged, your looking at about a minute for siding cars. Tops. The main issue is when he bleeds out for emergency, or is just starting up, when the resovoir is empty and has to fill itself before it can fill the train. More cars takes the resoivior longer, but a siding pickup is gonna be only a few cars, so snap your fingers and the models air system is loaded.

I tok and passed my air-brake exam, but I can’t tell you much other than it is largely full of redundancies. Essentially, the three extra tanks all work as a counterweight to the break shoes. any movemet of air changes the weight adn applies or realeases the brakes. The problem is that an empty air system=the same amount of change in the air as one that is full, or fully char

Thanks, Ray!

I can understand anything if it includes pictures/diagrams! [tup]

-George

On some roads “bottling the air” is a violation of the rules and a chargeable offense. With modern ABDW air brakes, bottling the air is asking for trouble. If one car senses a rise in air pressure, it will cause the car to dump the reservoirs into the train line and release the brakes, causing the next car to sense a rise in air pressure, causing it to dump its reservoirs into the train line and release the brakes, and so on and so on. End result is the whole cut now has it brakes released. The cars are designed to do this because twhen used as they are supposed to, the reservoirs dumping air back into the train line will help charge the trainline faster.

The air brakes on a car can bleed off completely in a matter of minutes. I’ve tested and timed it when we re-enacted the accident. That’s why the rules say that the air brakes cannot be trusted to hold cars when the engines are detached from the train and require hand

Here’s a good article on how air brakes work:

http://auto.howstuffworks.com/auto-parts/brakes/brake-types/air-brake.htm

On some roads “bottling the air” is a of the rulesviolation and a chargeable offense. With modern ABDW air brakes, bottling the air is asking for trouble. If one car senses a rise in air pressure, it will cause the car to dump the reservoirs into the train line and release the brakes, causing the next car to sense a rise in air pressure, causing it to dump its reservoirs into the train line and release the brakes, and so on and so on. End result is the whole cut now has it brakes released. The cars are designed to do this because twhen used as they are supposed to, the reservoirs dumping air back into the train line will help charge the trainline faster.


A slight clarification is in order for those that may be wondering… When you uncouple from your train you don’t release the air from every car in your train…You do set handbrakes on the first 2-3 cars(more if its a long cut)…This is not “bottling the air”…

As Dave stated on most roads “bottling the air” is a rule violation that can lead to dismissal or suspension…