daveklepper But if the helper, midtrain and/or rear, is radio controlled from the head end, then it does help by shortening the time the specific application, pressure reduction or the build-up for brake release, travels from the front to all cars on the train. And with sophisticated control, available, the engineer at the front of the train can, if skilled by learning from others and practice, individually control both brake and power of the helper, and thus have some control over slack action, very valuable for hill-and-dale railroading.
But if the helper, midtrain and/or rear, is radio controlled from the head end, then it does help by shortening the time the specific application, pressure reduction or the build-up for brake release, travels from the front to all cars on the train. And with sophisticated control, available, the engineer at the front of the train can, if skilled by learning from others and practice, individually control both brake and power of the helper, and thus have some control over slack action, very valuable for hill-and-dale railroading.
Just to be clear, on DP remote consists, independent control of braking is limited to dynamic braking. You can independently have the head end in dynamics and the DP consists in power. You can't have the head end in power and the DP consists in dynamics. Air brake operation however is always in sync with the head end. You can't set or release air on the DP remotes alone.
Jeff
daveklepperBut if the helper, midtrain and/or rear, is radio controlled from the head end, then it does help by shortening the time the specific application, pressure reduction or the build-up for brake release, travels from the front to all cars on the train. And with sophisticated control, available, the engineer at the front of the train can, if skilled by learning from others and practice, individually control both brake and power of the helper, and thus have some control over slack action, very valuable for hill-and-dale railroading.
Then it is not a manned helper. It is a distributed power unit under the control of the engineer on the lead engine.
Never too old to have a happy childhood!
As Balt says, the brakestand on any locomotive not in control of the train is cut out, so that locomotive is just another boxcar, brake-wise.
The independent still works, though.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
vbeachThis discussion about air at the end of the train brings a question to mind, how does all this work when you have pusher/helper locomotives on the rear of the train. Are they hooked into the train airline and are they also adding pressure? Can they also modulate the brakes?
Rear end and/or mid-train manned helper engines have their brake systems configured to act as just another car in the train. Helpers without a device known as 'Helper Link' must stop to disconnect the helper and close the trainline on train itself. With Helper Link the Helper can be disconnected on the fly, as the Helper Link 'connects the trainline' without a physical connection, but a radio controlled trainline connection. For manned mid-train helpers the train must be stopped to insert and remove the helper. Manned helpers are on trains for additional power, not brake control.
This discussion about air at the end of the train brings a question to mind, how does all this work when you have pusher/helper locomotives on the rear of the train. Are they hooked into the train airline and are they also adding pressure? Can they also modulate the brakes?
SD70M-2DudeThe former uses a lot of air to blow the whistle, while the latter uses very little.
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Electroliner 1935 BigJim Needless to say that all of that stupid whistle blowing was releasing the brakes on the train I would expect that blowing the whistle with train line air could cause a stronger application of the brakes, not a release. Unless the whistle was supplied from the brake cylinder air line which is not likely. On our caboose (ex IC) at the Fox River Trolley Museum, the whistle is supplied from the train line as is the brake valve. The amount of air the whistle uses is small compared to a brake application.
BigJim Needless to say that all of that stupid whistle blowing was releasing the brakes on the train
I would expect that blowing the whistle with train line air could cause a stronger application of the brakes, not a release. Unless the whistle was supplied from the brake cylinder air line which is not likely. On our caboose (ex IC) at the Fox River Trolley Museum, the whistle is supplied from the train line as is the brake valve. The amount of air the whistle uses is small compared to a brake application.
What you are forgetting is the pressure-maintaining feature of the locomotive's brake valve (which adds air to the brake pipe to compensate for leaks and avoid a brake application growing stronger and stronger from those leaks) and the ping-pong effect that is created by the shutting of a valve while air is flowing through the brake pipe (think sloshing of water, but with compressed air). Both of these, whether separately or together will create a momentary rise in pressure at certain spots. It only takes a 1-2 PSI increase in brake pipe pressure to release the brakes, and modern car control valves add air from the car's emergency reservoir back into the brake pipe to speed releasing and recharging the brake system, so once one car releases a chain reaction is created and the whole train will release. The Engineer will be unaware of this until he notices the airflow meter in the cab spike up, and/or the change in brake pipe pressure either on the cab or EOT gauge and by that time the brakes will have released and the train will be accelerating.
Also the air whistles I am familiar with use a surprising amount of air and improper use of them can cause all sorts of havoc, the first time I went to use one I put my train into emergency by opening the valve too quickly, boy was the Engineer ever mad... never made that mistake again!
I should also note that there are at least 2 kinds of air whistles, the type currently found on CN have a valve similar to an angle cock, where you turn a handle to open/close it. The other type, which we use at my local Railway Museum has a button that you push to blow the whistle, and a handle to put the train into emergency. The former uses a lot of air to blow the whistle, while the latter uses very little.
Greetings from Alberta
-an Articulate Malcontent
BigJimNeedless to say that all of that stupid whistle blowing was releasing the brakes on the train
CSSHEGEWISCHThe valve was apparently a ratchet device that could be used to bring the train to a controlled stop by opening the valve a few notches at a time. The valve could not be closed until the train came to a stop and the valve could be ratcheted around to the closed position.
That is true. You didn't want to screw around trying to run the train from the rear as has been sugjested. If the engineer has applied the brakes and you go messing with the air by releasing more air then closing it off you will get a complete brake release through the entire train. I was down at the VMT when they were giving people rides up and down the track. Backing into platform is downhill and a certain volunteer crew member was blowing the caboose whistle while the engineer was trying to spot the train and having to use the automatic brake to come a safe stop. Needless to say that all of that stupid whistle blowing was releasing the brakes on the train and causing a very unsafe operating condition!
Quite some time ago I read in a railroad magazine where enthusiasts Overseas riding an excursion hauled by a steam locomotive were applying and releasing a hand brake in the passenger train to 'make the locomotive work harder' = louder.They did it in a tunnel, the engine slipped to a stop and stalled for steam.As I remember, there were problems with the passengers/crew?????? overcome by smoke.Maybe, in hindsight, they should have cut off and run light engine outside, built up steam, and returned sanding as they backed in???? whilst Train Crew secured train.
Maybe they should have backed out??On the road, engine crews on Pushers behind the Caboose would apply locomotive oil to rails behind their tender so following train would stall, and have to double.Between Union 'Brothers' of course.Same mentality that lead to long strings of Torpedoes set in tunnel by caboose crews, or in thru small towns with elevators on one side to reflect the sound townward, knowing the next train would be about 0230 nite.We once made a Snowman and put it btwn the rails w a Red Flag and a Train Order Hoop w/ Orders.The Wyft Engr took it well. Now long gone from Cancer.Thank You.
rrnut282Just curious, did the conductor in the caboose "play with the air" to screw with an engineer?
I wouldn't bet against it having happened from time to time.
Just curious, did the conductor in the caboose "play with the air" to screw with an engineer?
Sorry I took so long getting back.
Thanks for the replys. It sounds like it was possible but not done often, if ever.
Carl, Thanks, was thinking about you and Pat the other day looking at the fire damage in Cajon. Glad hill 582 was spared.
NDG, Thanks for the replys & links.
letting off a little bit of air won't do a thing, as someone who drove a tracker trailer for a living, what I would say is that if you could add a little bit of brake when starting that would help take out the slack and it would do the same thing going down a grade, be a little hard on the brake shoes, because all the ones I ever saw were so far out of adjustment if they were on the road a cop would give you a tinket for them being out of adjustment, never got a ticket for that, but I also kept mine adjusted, when I came down a big grade, I kept my foot on the brake just a little bit, or just when it moved on the gage, never had to use a runaway ramp, but seem where someone did, in my 30 years of driving.
I've read Special Instructions from PC employee timetables regarding the brake valve on the caboose. The valve was apparently a ratchet device that could be used to bring the train to a controlled stop by opening the valve a few notches at a time. The valve could not be closed until the train came to a stop and the valve could be ratcheted around to the closed position.
This tends to jibe with my memories of IHB freights coming onto the SC&S at Wolf Lake Junction (135th Street & Mackinaw) when the conductor would stop the train with the caboose brake valve to throw the switch at the junction and call the dispatcher to advise him of that action.
More.http://www.trainweb.org/oldtimetrains/photos/cpr_rolling/vans.htmlIn photo w/men, Red emergency rope centre, above.Actual valve behind open cupboard door.Water tank for basin on right, porcelain metal basin was inserted in hole in counter, which had drain.Many Cabeese had a second water tank on floor to right of one on counter, where it's slopping from Slack rotted floor.Both tanks would have 2 inch thick square of wood plank floating on water top inside to curtail slosh.Ice box and other cupboards under cupola beyond.'Wood' Cabooses such as these usually had Steel Under Frame, leaf springs, were soft riding and the wood absorbed sounds well.A nice ride at lower speeds on 39s. Listening to the fire, when stopped, hearing the Air and Brake set and release, etc.The true ALL WOOD cars were fragmented when the Diesels came.CP had three 3 post-war Steel Bay-Window Cabooses.http://www.bigdoer.com/wp-content/uploads/2014/06/P1030221-640x479.jpgCrews hated them for may reasons, the main reason being they felt exposed in Bay Window at night if equipment foul and too close on adjacent track @ Switches. Ditto loose rock, fallen trees etc. in Dark.View obstructed along train on curves by bank, snow, rock, that would be visible from Cupola designThere was one here, used as a Rider Car out to sawmills by Yard Crew.Caboose used as portable Train Order Office in Double Track when one track removed from service account MoW such as Steel/Surfacing/Tie/Ballast gang.http://1.bp.blogspot.com/_kawpWTOGqPk/Sdfnsfgu3SI/AAAAAAAAAnk/SHZ84UMT2gE/s400/blogloose4.jpgThank You.
Late model B&O cabooses were eqipped with a back up brake valve, as well as a remote anglecock operating device. They can be viewed in this picture. The anglecock device is the T handle to the right of the reflectors, the back up brake valve is to the right of the T handle.
CP Cabooses back in the day had an open/close air valve with a handle above the sink which was activated by pulling a red rope end to end threaded through screw-in eyelets on the ceiling. There was an air gauge in the cupola and another over the Conductor's desk, by the lamps.When Backing Up planned for long moves, a Back Up Hose was coupled to rear Angle Cock on train line, it having a lever-valve, an Air Whistle and a 'Big Hole' Pipe Tee for emergency. The valve was 'cracked', air flowing out the big hole. The Conductor covered the hole w/his hand to sound whistle, and could open valve wide to apply Emergency.Back in the Day, on Work Trains and Helpers, Crews applied redundant Steam Locomotive headlights to Caboose Roof Rear Running Board w/clamps and ran wire to receptical on Tender for running back in Reverse lite w/engine as in a Pusher going back down w/o turning. Photos exist on line.There was a fusee rack in Cupola holding about 20 fusees in holes along with a Yellow cloth flag, usually on a piece of Train Order Hoop for for waving 'Highball' to head end when out of siding and by Green flag on Slow Orders.Trainman's lamp used at nite.Often three lamps. One wick type w/chimney over sink on left, another wick type over C's desk, and alongside the latter, a pump-up Coleman Mantle lamp, the latter REALLY Hot.Anyway, about 55 years ago I travelled on a CNR 'Wooden' Caboose, Orange w/Maple Leaf, White,Up in it's Cupola was a small brake valve similar in size and shape as found on a Streetcar, it's handle moving in an arc horizontally, with a flat quadrant w/ notches for spring and plunger inside handle as on locomotive brake valve.I assume the reduction could be governed with this valve to meter air exhaust from T L, or be moved right to Emergency on far end, if required.I know they used the train line valve to halt movements when backing up into stations or freight sheds, and on ore docks, etc. I have never seen it used to set brakes from the tail end when pulling, but, anything is possible, and crews did do non standard procedures on the road.( One old Engineer said, that, in Steam Days, they would raise train line pressure from locomotive feed valve, and then, after tipping over a grade, reduce same from feed valve, NOT using Brake Stand at first, causing front cars on train to set up, creating drag, but, not all at once. )One fear might be, if the tail end initiated reduction came on too fast, or not smooth enough, it might put train into emergency from tail end with throttle open until PC valve actuated on Units.
Back in the Day.Thank You.
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The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
CShaveRRI could swear that I saw some caboose valves somewhere along the line with notches in their air-valve mounting that closely mimicked those on locomotives' automatic brake valves. Not sure whose caboose I was in, except that it wasn't from the old home road! And I can't think of any other use than a controlled "pulling" of the air.
Some of our ex-PC cabin cars had/have those valves. Located inside near the bay window, it was a rotary type knob with markings for 10lb, 20lb, etc.
My experience with a back-up hose and pressure maintaining is that if you crack the valve ever so slowly, you can actually have it open all the way and the brakes won't set.
If you're using a six brake (or equivalent) it might work. I would imagine that's why such signals worked back in the day (ie, dipping the brake line to signal the engineer).
Welcome back, Chad!I could swear that I saw some caboose valves somewhere along the line with notches in their air-valve mounting that closely mimicked those on locomotives' automatic brake valves. Not sure whose caboose I was in, except that it wasn't from the old home road! And I can't think of any other use than a controlled "pulling" of the air.
Carl
Railroader Emeritus (practiced railroading for 46 years--and in 2010 I finally got it right!)
CAACSCOCOM--I don't want to behave improperly, so I just won't behave at all. (SM)
Thanks Sam, Can't remember who I left the popper with Been so long since I had a chance to poke around in here
Have I missed any key plot points?
, Chad ! and it's nice to see you back, and you've brought your popcorn popper, as well!
...no this isn't a bad bar room joke
Haven't been around in a while, hope all are well.
Been reading some books on old school railroading that talk of all the injuries the guys on the rear got from slack action. Most of those happened running in "hogback" territory (where the train is long enough to be going up/down two hills at the same time). It got me wondering... did the conductor ever take air from the caboose to help controll slack run ins?
It seems to me that if you took a few pounds off the pipe at the rear as the caboose was approaching the crest and at the appropriate time close the valve and let the air recover, you could controll that "crack of the whip" action at the rear end.
I know the caboose desn't have a EQ res. ect. and it would be a manual operation controlling the pipe pressure, but was it done????
My logic is that you could get a 5-10 lb. reduction at the caboose that would "taper" tward the front of the train where the power was trying to recover the air (assuming a pressure maintaining feature) instead of the "draging" the whole train through the "hogbacks" or pummeling the the cab crew.
Could this be done from the conductors valve? (I'm guessing it could as the SP used the trainline pressure to communicate in snowshed territory)
Would this work practicaly?
Were there rules against this?
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