First Post/Braking Question

Trains Magazine General Discussion
1

Greetings all,

A brief history of me before my first post: My name is Matt, I’m 24 years old, and I live in Columbus, OH (go Bucks!). I’ve been facisnated with trains my whole life; my earliest memories are watching Conrail trains go by in my cousin’s back yard for countless hours.

I don’t know much about the details of railroading, but am hungry to learn.

I’ve been lurking on these forums for a while now, and have finally decided to introduce myself. Though I’ve never worked in the industry, I’ve always been a big fan of trains (watching, reading, and yes, even enjoying Extreme Trains). However, as I am just starting to really get into the nitty-gritty of learning of trains and railroads, a number of questions have come up. I’ve gathered that the vast majority of posts here are well-thought, intelligent insights and would love to contribute to the discussions.

One of the nagging questions I’ve had: what is the difference between the train brake, independant brake, and dynamic break? In what situation would each of these be used?

Thanks in advance,

Matt

P.S - I have looked over the ABC’s of railroading on this site (which has been immensely helpful). If you have any other sites to recommend, I’m all ears!

2

Hey Matt !

First - welcome to the Forum !

Train brake is for the entire train - including the locomotive(s).

Independent brake is for the locomotives only - and as the name implies, can be and is operated independently of the train brakes. The independent can be applied when the train brake is off, and it can also be released (“bailed off” is a common term) while the rest of the train brakes are left applied. EDIT - See Al Krug’s page linked below for the more correct answer.

Dynamic brakes are on the locomotives only, and essentially use the traction motors as brakes - crudely and simply, kind of like slowing a stick-shift car or truck by downshifting it, or maybe with a "JAKE Brake "engine exhaust brake.

For more of the whys and wherefores, wait for the rest of the replies !

In the meantime, I’d highly recommend that you check and and study Al Krug’s “Railroad Facts and Figures” webpage at:

http://www.alkrug.vcn.com/rrfacts/rrfacts.htm

Most of your questions are covered at the end of his page named "How RR Air Brakes Work - Part I ", or “Freight Train Air Brakes of North America”, at:

http://www.alkrug.vcn.com/rrfacts/brakes.htm#dynamic

Enjoy !

Look forward to seeing you here more often !

  • Paul North.
3

Matt: Welcome!

Paul, the part you crossed out is not incorrect; you just phrased it differently than Krug did.

4

I’ll resist the urge to put out the Welcome Matt. Welcome, nonetheless! You probably have a pretty good idea of who’s who already here, and know the people who can give you authoritative answers on just about any subject. Questions are most assuredly welcome–they often lead to interesting discussions as well as good answers.

5

Matt - welcome aboard. Al Krug’s essay on the subject is probably the best you’ll find. Once you’re through that, come on back and ask away!

One very popular thread a couple years ago was entitled “Stupid Question Thread.” It was anything but - a lot of good information was shared there and we’re all a little smarter because of it.

6

Welcome, Matt. As Paul, Zardoz (if he signed his posts, I’d have said Jim), Carl, and Larry have said, come in, ask questions, share your knowledge. We all enjoy sharing what we know and learning more about the best form of transportation ever.

Johnny

7

Here there Matt…

Independent brake…read as locomotive brake, and only locomotive brake, acts independently of the train brake, is used to apply brakes only on the locomotive, and when kicking or switching cars, and the lag time to recharge the train brake line is a hindrance, or when moving “light” locomotives around.

Works off a separate brake handle from the train brake.

Train brake, just what the name implies, an air brake system on the entire train.

When used, it also sets the independent brake as well as the brakes on the cars…when doing a brake pipe reduction on the train brake, (braking the entire train) you can “bail off” or release the independent brake while still applying the train brake.

This prevents the wheels on the locomotive from locking up and sliding because the locomotive is getting “pushed” by the weight of the train behind…it also allows for stretch braking where you use the weight of the cars and their brakes to bring the train to a halt with all the slack “stretched” out.

Train brakes set up from the head end first, and apply backwards down the train at the speed of sound.

If a train breaks in two, the brakes will set up from the separation, both parts applying away from the separation.

Dynamic brakes…a system that switches the DC traction motors from using electricity to generating electricity.

When the dynamic brakes set up, the weight of the train rolling down a grade will spin the wheels of the locomotive, creating an electrical current from the traction motors, which is dissipated through the dynamic brake grid, which is just like heating element in your electric oven or range, only much larger.

Using Back Electromagnetic Force, this creates electromagnetic resistance in the traction motors, making them hard to spin, which in turn retards the speed of the locomotive.

You use this when there is a need for a constant braking f

8

Hi all,

Thanks everyone for the kind words of welcome, and the links to additional information; I’ll certainly have some reading material tonight.

I’m excited to join the board! Although I don’t know very much yet, I’m starting to scratch the surface and it’s very exciting to start studying something I’ve been interested in for so long. There’s a mystique about railroading that can’t be explained or defined, it has to be lived and experienced and I thank you all for imparting your knowledge and being patient with a newbie.

9

Welcome to the fomer forum bro’! The dynamic brakes are used like this. The engineer moves the combined power handle,the throttle, into DNBK. SETUP. He let’s it set there for 30 seconds or so then he will push the handle into B1, 2, 3, etc. The dynamic breaks take power from the traction motor’s and basiclly turns them into big resistor’s , thus the term dynamic breaks. the energy is then exausted out of the side of the locomotive as heat.

The train break’s are used to supplemen’t the dynamic break’s sometimes most often though to stop. The air break or automatic break handle in the loco’ is moved forward causing air to flow though the air hoses on the entire train then the air enter’s the air resivour’s pushing the break shoe aginst the wheel thus slowing the train. sometimes you can run out of air. That’s bad especially on a grade because you can’t apply any form of air break!

The locomotive break is basically the same thing and is operated the same way as the train break. But it only work’s on the locomotve and it can operate indapendant of the other break’s. Hope you will contact me if you have any other queston’s about railroading, mackjs01@sbcglobal.net . Enjoy the forum, and enjoy being a railfan buddy!!![swg][:D][8D]

10

You betcha, Matt.

David P. Morgan - the late, great Editor of trains - once observed that the railroads were the great civilizing and modernizing force in what we would now call the “Third World” - Africa, India, Asia, etc. They introduced mechanical systems , organizations, the Industrial Age, etc. to what were then regarded as primitive peoples.

Someone else on here has as their signature or "tag’ line, “If you want to find history, follow the train !” .

For my part, I’ve been in, seen, or read about just about every aspect of the human condition in, on, or around the railroad, including the arts (except maybe dance). Have you heard Gordon Lightfoot’s “Canadian Railroad Trilogy” yet ?

So as a working philosophy, I’ve come to the conclusion and believe that “It’s all on the railroad; and that if it’s not there, it’s probably not worth much” (at least not to me), and I don’t have much use for it otherwise. Some exceptions, sure, but I’ve found that if I want to know about a place - country or city - start by learning about their railroads (or trolleys, etc. if they don’t have any rail lines). If nothing else, it provides a frame of reference for inquiry and study. For example: Did you know that there were - and still is at least 1 ! - railroads on Hawaii ?

Anyhow, welcome again.

11

Matt & Forum-ers ,

As Matt stated in his “first post” this is my first time posting in this forum . As an intro , they call me The Travler . And , I have been around the R.R. all of my life . Learned my numbers and alphabet off the sides of freight cars that ran along THE SOUTHERN RAILWAY . Have been getting PAID to be around the railroad for the past 35 years (6 years 11 months & 28 days till retirement) .

As for your questions Matt , they have been answered pertty well by those on the forum already . The only point that I could possibly add-on to those responses would be that as with anything on the railroad , SKILL in operating the various brakes is what makes the differance . Sort of seperates the “OPERATOR of LOCOMOTIVE” from a “LOCOMOTIVE ENGINEER” .

I am very glad to see a younger person take an interest in RAILROADING , ya’ll be safe out there . And if the Master Railroader up there brings US back safely from our run , I’ll be back on-line later this week . THINKIN’ & BEIN’ SAFE The Travler.

12

Matt–and all others new to the forums–we have a great opportunity to learn quickly from other people who share our interests in railroading. When I became interested in rail transport, I was limited to the encyclopedias at school, and a book given me by an uncle, The Modern Modern Wonder Book of Trains and Railroading, and such passenger timetables that I was able to pick up. The summer before the 10th grade, I planned a trip by rail from Charlotte, N. C., to New Orleans to Chattanooga and back to Charlotte, which my brother who was just older than I and I took. The next spring, I discovered Trains, and my rail horizon was expanded greatly. Since then, I have subscribed to various railroad magazines at one time or another (my subscription to Trains has never been allowed to lapse), and have learned much from them. Also, for twelve years, I had a great deal of interaction with railroad men–agents, trainmen, and enginemen, sometimes even working with them–despite never being employed by a railroad.

The internet has opened a new door on information and, to a certain extent, we are limited only by our knowledge as to where to look for what we want to know.

Johnny

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Am I the only one who got that? Haha [(-D]

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No, I saw it and accepted it as being from Carl.[(-D]

Johnny

15

One correction. The train brakes don’t work by causing air to flow from the locomotive through the air hoses causing the brakes to apply in the individual cars. That’s a common misconception. The locomotive does, of course, supply the air for the system, but it does so by filling (charging) air tanks on each of the cars throug

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Amen trains are of course awesome!!![:D][:D][bow]

This is trucking…[zzz][xx(]

17

A slight correction here, as well.

The traction motors are turned into generators, not resistors. The electricity they generate is then applied to large resistor (more or less heating elements), the heat from which is then discharged from the locomotive by a fan.

You can experience a form of that by turning on your headlights while your car is idling. As you do, you’ll hear the engine load down a bit because of the larger load on the alternator.

Those who have used the generators that used to be popular for powering headlights on bicycles should be very familiar with the principal.

18

Edblysard said, yesterday afternoon:

“Train brakes set up from the head end first, and apply backwards down the train at the speed of sound.” [my emphasis]

How can the application travel at the speed of sound? air does not travel that fast. A wave is set up by the reduction in pressure, and the magnitude of the wave is proportional to the amount of reduction. This wave travels at the speed of sound, and its magnitude determines how much air the control valve on each car will admit into the car’s brake cylinders.

Ed also said, “If a train breaks in two, the brakes will set up from the separation, both parts applying away from the separation.” And the reduction in pressure when the air hoses part is the same as that when the engineer “big holes it”–from the maximum pressure in the system to atmospheric pressure; the full pressure in the car tanks, within the limits imposed by the system, is applied to the brakes, to stop the train as quickly as possible.

Falcon48, would you be interested in giving a brief discussion of vacuum braking, especially as it is used in Great Britain? On a new thread?

Johnny

19

More correctly, an emergency brake application travels through the train line at a speed that approaches the speed of sound as a theoretical limit. Air is exhausted from the train line at each car’s valve in an emergency brake application, triggered by the sudden change in pressure. The train line for any given car is longer than the car’s length (by as much as ten feet). If one is standing alongside a train when it goes into emergency, the sound of the application going through the train is a hard-to-forget experience.

20

Hello again all,

A few things I wanted to bring up:

-Thanks again to everyone who took time to write out explanations to my question. I’m now either more knowlegable on the subject than ever before, or so confused I don’t know what to ask next (I kid… definately the former).

  • Paul, I really enjoyed reading about your working philosophy, and I must say the more I re-read what you wrote, the more I find myself agreeing with you. You had made mention of Gordon Lightfoot’s Canadian Railroad Triliogy; any ideas where I could find this?

  • Finally, I’d like to second the idea of a discussion on vacuum braking. Coming in, I was vaguely familiar with independant, train and dynamic, but I’ve never heard of vacuum braking. Any insights would be great!

Thanks again,

Matt