Steam & Excursion > The Fable of run-away broken straight air brake trains.

All straight air brake trains did not lose all their braking capacity if they were equipped with this type of glad hand that contained a shut off valve.  It a hose came uncoupled to the next hose the internal valve would close and retain any pressure in the train line.  The end connected with the locomotive would retain the same control.  If air brakes were being applied to the train when the train broke in half, the end separation would retain pressure for a while and stop the cars. It the train was going up a grade and the link broke and brakes had not been applied, then the train was only under the control of the crazy brakeman working on top of those car who could apply hand brakes or join the birds and fly off. 
Engines and cars with these glad hands did not have angle cocks where air could be shut off.  Photo of log bunk show the lack of angle cocks.  Their were two typed of straight air brake system.  The glad hands would mate but without a special insert of the white ivory X, a special adapters was needed to open the glad hand valve if used with a normal glad hand.  More photos to follow.

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These are now commonly referred to as "Quick Couplings:, "Quick Disconnects", "Dry Break Couplers", etc
and have been around for many years. Not sure if the glad hand version came first or not. Straight air can give
a much better braking "feel" than "automatic air" by virtue of the fact that brakling force at the wheels is directly
proportional of the train line reading ie more pressure equals more braking action. It does have some drawebacks
as mentioned. Fact is, if you're running on straight air and NOT braking, a hose break (couplers or not) leaves
you with zero braking. Makes for a real interesting time at that red signal.

Out 



Edited 1 time(s). Last edit at 03/22/20 11:17 by callum_out.

The operative words being:

"...if they were equipped
> with this type of glad hand that contained a shut
> off valve. "

All cars in a train had to be so-equipped..
A rare, and special-purpose solution, not used on cars in 
interchange service..

Works good, til the ( isolated) cars'  brakepipes' leaked-down...
then,  "it's off to the races.."...

 

This Glad Hand was found on the Pagosa Lumber Co. log railroad north of Pagosa Springs, CO on the grade that was used 1908 to 1911 so the sun has nearly destroyed the packing ring (gasket)  It cost $2 a pair but you did not need a angle cock and that was some saving.  If you see that hex head on a glad hand, then you know that was a special straight air brake system of that company.



Edited 2 time(s). Last edit at 03/22/20 17:55 by PlyWoody.

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So, which railroads, in interstate commerce, used this system?

Correct answer: NONE..


​W.

These log cars moved down to Dulce, NM and continued to work on the Pagosa Lumber Co.

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I have photos of common-carrier railroad with these valve glad hands but they are PGN files and too large to post. It all a matter of time frame you are talking about.
Wes is only right for after 1903, not before. I bet our friend from NZ can find those photo in Colorado Hist. Society collection.



Edited 1 time(s). Last edit at 03/22/20 12:17 by PlyWoody.

OK...????

So, I 'get' the fact that the spring-checked glad hand, trapped the air in the the case of 
a train separation ...  
In a straight brake system,  the brakes can only be applied if you pressurize the brake pipe, right?

Let's say the train separates .... the front half of the train can build-up pressure
and be brought to a halt...

The back half has no way to get air to apply the brakes....if rolling up-hill,....what stops the freed cars from rolling backwards?
 If the train is rolling downhill, what stops a "run-in" collision?

Were these ever used in passenger trains?
Where? 

​W.

With the straight air system, the locomotive engineer would run with air pumped into the train brake line just enough to have brake shoes lightly dragging but he would adjust the throttle of his power from the locomotive and drag the train.  If the train broke apart the valves would close at the glad hands and retain that braking effect on both parts of the train.  The engineer would feel the surge as he lost his rear half of train and would then close his throttle and stop to back up to recouple to his train. He did have brakeman on the train to work hand brakes by whistle signals. In most cases they already knew what happened. 
Passenger trains, very likely before the development of the automatic air brake system by Westinghouse.

All the cars in the train did not have to be so equipted but only enought cars coupled to the engine to have enough brakes to handle the train as the railroads desire.

Before Oct 30,1911 all the nation railroads were very familiar with handling intrastate revenue cars and non-SAA compliance and MofW cars on the rear  back half of any train, as the Safety Appliance Act only required the engineer at one seating to have full braking control of the half of his train (50%).  The ICC at the time was even accepting it, if only the first third of the train was all air operated brakes. On that date a Judge in the Atlanta Federal District Court, ruled that trainmen did not have access to seeing the way bills of all the cars (interstate compliant or non-compliant intrastate) they handled and after a long case SOU v USA, said he did not have jurisdiction but ordered that every car moving on the interconnect highway of the National Railway System will be only SAA compliance cars. At that point, none of the nations' railways appealed to the US Supreme Court, and moved all non-compliant cars into MofW service, sold them to private railroads or burned them up. 

 



Edited 1 time(s). Last edit at 03/22/20 17:25 by PlyWoody.

In your two examples, same answer, nothing! As I said if you're running with zero air pipe pressure ie uphill,
separation doesn't change a think, you've stil got zero. Downhill the separated section would have zero brakes
and hence the invention of the "opposite" minded Westinghouse system and the triple valve.

Out 

To mate a standard glad hand to the valve glad hand only required a perforated metal washer that fit inside the packing ring on the standard glad hand and that would touch and push the valve up when the two glad hands were mated. Very simple item and easy to apply when coupling mixed cars.

So let me get this straight...*
You can mix pressurized air ( conventional) brakes with straight air cars...
So if your feed valve is set for 70 psi, the 70 psi goes to the straight air cykinder ..
and applies the car's brakes  --- SOLID!

How does the screen in the glad hand help any thing?

​W.

(Let me get out my B/S filter, first.)..



Edited 1 time(s). Last edit at 03/22/20 18:39 by wcamp1472.

Yes and when you dump the air to set the auto brakes the straights will release, doesn't that sound like
a fun day at the office? 

Out 

Sorry I have to explain it further but that is OK, the automatic air brake cars mixed into the straight air train had their brakes cut-out and their air line was used to feed the cars beyond.  Brakeman climbed under and turned the cut-out valve.  Engineers still  had control of 50% of the cars in the train as they did not need to have all the operable brake cars on the front end of the train.

Did anyone else enjoy the photos of the San Juan area narrow gauge train or were learning anything of interest. End of class.



Edited 1 time(s). Last edit at 03/23/20 06:32 by PlyWoody.

So, in case if a break-in-two,
You still have a run-away train
portion...

There’d be no way to build up
Pressure .. on the uncoupled cars..

Or, if you had the cars equipped with triple-valves ( cut out) grouped
at the front of the train, next to the loco... all the cars would let the
air pressure whistle out open TrainLine..

Or, if the TrainLine ruptured at other than the glad hands... busted hose
etc...., you’re still running-away...

That’s not a fable...
Or, it’s a fable with a twist for a moral..

All things are true, except when they’re not true...

W.

Posted from iPhone

Fables or realities there's a reason straight air is only used on locomotives these days....and yes, don't release the handbrake on a standing locomotive that has not built up some air pressure! 

"don't release the handbrake on a standing
> locomotive that has not built up some air
> pressure!  "

Sounds like the voice of experience!
(Luckily, of the mistakes( and regrets) that I've made, that's not one of them...).

​W.

 

wcamp1472 Wrote:
-------------------------------------------------------
> "don't release the handbrake on a standing
> > locomotive that has not built up some air
> > pressure!  "
>
> Sounds like the voice of experience!
> (Luckily, of the mistakes( and regrets) that I've
> made, that's not one of them...).
>
> ​W.
>
>  

D'ya know, it really doesn't take much to get one of those things rolling. So i've been told.

-LD

And worse, they have a tendency to keep rolling! 

Out 

Oh, yeah. This is the steam forum. Handbrakes are rare, but be sure to properly use that chain!

I like tossing the chain in a horizontal arc against the engineers side main driver so it catches and wedges in between th rail, the flange, and the tread. Then let it hang loose along the rail, and pack it in behind the driver between the rail, the flange, and the tread.

-LD