Eames Train Brakes - Official Work Thread

[Keith Taylor]

In the new issue of our museum's newsletter, Ellis Walker discusses the Eames Patent Vacuum brake. I can see why this brake was abandoned in favor of the Westinghouse automatic brake. If the train becomes seperated...the brakes release on the train! The form of vacuum brakes as used in the United Kingdon is the exact opposite, as vacuum is applied to the brake cylinder on the train at all times. A vacuum eductor was operated at all times to keep the vacuum applied to the train, which held the brakes released. The engineman then would regulate the amount of vacuum to the train, by which means he could change the vacuum level. As the vacuum level approached atmospheric, the brakes would apply slowing or stopping the train. The British version of the vacuum brake is a very effective brake system, easy to control and giving smooth service applications of the train brakes and fully as fail safe as the Westinghouse air brake. Does anyone know if any other two foot gauge lines used the Eames brake...as opposed to the automatic vacuum brake like that used in Great Britain?
Keith

[Stephen Hussar]

Very interesting question, Keith...if no one here knows, this would be a good question to ask over on the RyPN.org Interchange...

[John Kokas]

The answer to your question is that the Eames brake was quite popular with the NG community.  It got it's first big boost by being used on the NY elevated railway.  But its biggest selling point is was that it was CHEAP.  It's downfall became apparent when train lengths were increasing over 8-10 cars and the system could not overcome leakage in the train lines which resulted in loss of braking control.  

What the RR community learned was that the Westinghouse system was superior do to the increased efficiency and availability of compressed air over vacuum.  If my memory serves me correctly the RR convention of 1898 (modern day AAR) put the Eames system out to pasture for interchange traffic at that time.  Some examples stayed around for some time due to shortline NG railways essentially having "captive" rolling stock so the rule didn't really mean anything to them. This is also why larger NG RR's changed over to the Westinghouse triple valve or "K" brake.  Best examples of those are the D&RGW and EBT which lasted up to their ultimate end of service.  Most of their historic equipment today is still running on "AB" systems which were out of regular service on most Class 1's by the 1960's.

In today's world I would predict that Eames equipped equipment (try saying that fast) would not be allowed for interchange under either AAR or FRA rules.  Hope this helps.

[Paul Horky]

Steve in answer to your question yes other MTF's did use vacume systems. The SR&RL did till bought out by the Maine Central at which time a swich to air was started with some equitment haveing both air and vacume. Belive That the B&H also originaly used vacume system. If i'm wrong someone can jump in.

[Stephen Hussar]

Paul, thanks but it wasn't my question...it was Keith's. Also, after looking at Gus Pratt's Bridgton footage (quite a few times), I can say with certainty that the B&H did not use air.

[Paul Horky]

So sorry To you Steve. But I think I answered the question even if it wasn't from you. Keith hope this answers your question.

[Keith Taylor]

I'm a little surprised that the other and larger lines used the Eames system and not the better British system that applies the brakes in a train parting. The big reason that the Westinghouse air brake became popular was the feature that allowed the braking force (in this case high pressure air) to be stored on each car in the train. In a train seperation, air from the main reservoir and emergency reservoir are dumped into the brake cylinder. Simply....if the trainline is broken, the anchor is tossed out.

[Keith Taylor]

In todays world I would predict that Eames equipped equipment (try saying that fast) would not pass muster with either AAR or FRA.

Hello John,
It would certainly not meet AAR interchange standards! I'm not sure about the FRA however....I believe their rules just cover "power brakes" which would include "automatic" vacuum brakes. I believe when the Flying Scotsman and train visited the US back in the 1970's the vacuum brakes were retained on the locomotive and British Rolling stock. I clearly remember seeing the Gresham and Craven eductor in the cab. Further to my earlier question....did any US railroads ever employ the "automatic" vacuum brake. or only the Eames version?
Keith

[John Kokas]

Keith, as far as I know and have read the "Brit" version was not used in the U.S.  It may have in Canada.  There is one example that I know of that has the "Brit" system on it and is the Pine Creek's Lady Edith (Stephenson 1892?)  I know since I fired her way back in the early 1980's a couple of times.  Something to see - a copper sheet firebox.

Also the 1970's was a far different time.  Steam on mainline excursions, friction bearing cars in interchange, AB brakes, etc etc.  Not to mention lots of political horsepower leaning on the FRA from the State Department in order for our cousins across the pond to avoid any possible trouble.  Times have changed............

[Steve Smith]

Does anybody know of a book giving a general description of the British fail-safe vacuum brake system?

I can envision a system that would be essentially an exact INVERSE of the basic American system. There would be vacuum in the train line and in the auxiliary reservoir in each car. To apply the brake the engineer would operate a valve in the engine that would allow air from the atmosphere to enter the train line, reducing. This would unbalance the triple valve in each car and cause connection between the auxiliary reservoir and the brake cylinder, so that one side of the piston would have vacuum and the other side atmospheric pressure. The resulting force would act against a spring that normally holds the brake shoe against the wheel. To release the brakes the engineer would cause the eductor on the engine to restore the lost vacuum in the train line.

But I don't know whether this is actually how the British system works.

[Bill Piche]

To sorta kill two birds with one stone, there is a bit about most breaking systems seen on British locomotives (along with a bunch of other stuff) in "How Steam Locomotive Really Work".


http://www.amazon.com/How-Steam-Locomotives-Really-Work/dp/0198607822

This book describes the anatomy and physiology of the steam train, to enable all train enthusiasts to understand the workings of the various types of engines in use. It covers the design of the engine, the process of converting fuel into mechanical tractive effort to haul passenger and freight trains, and the function and design of the various components of the engine. The authors also outline the reasons behind the safe and efficient operation and maintenance of steam locomotives.

[James Patten]

Alas I don't think any of us thought to inquire about the vacuum brake system when several of us were over in Wales a couple of years ago. 

[Steve Smith]

Blimey, mates, I think I've found it! The explanation of how the British vacuum braking system works, that is. Will have to read it more slowly to be sure, but this looks promising:

www.railway-technical.com/vacuum.shtml

I notice that if you click on the drawings they enlarge

[Ira Schreiber]

Spot on, Steve. A jolly good explanation with no rubbish.

[Tom Werb]

I'm looking forward to #9's return to steam; hope to get up to Alna to see it.

Question:  Will #9 have working Vacuum Brakes??

If so, #9 may be the ONLY operational U.S. steam loco with working 19th-century Vacuum Brakes.

IIRC, only the SR&RL made a complete conversion to Automatic Air Brakes, but #6 did not
get the Air Brakes before going to the K.C. & W.W. & F.

Extremely-Narrow-Mindedly,
Tom Werb
Preston, CT.