VGN Ry, 100 Car Test Train in 1918
NW Mailing List
nw-mailing-list at nwhs.org
Mon Apr 13 07:07:06 EDT 2020
Well, Mr. Burnett, this all sounds like an evolutionary step to the AB
brake. There is a divided reservoir with train and emergency air (in
case you piss away your train line pressure) and there is primitive
attempt at pressure maintaining through the train with a special device.
Once we had it, we flatlanders on the NKP manipulated the AB by making
a small reduction of 6-8 pounds and then keeping pressure constant by
turning the feed valve. But our grades were short and mild. How this
would work on long grades down below (N&W territory) I do not know, but
maybe some N&W or VGN enginemen can tell us how the air was used with or
without triple valve assistance.
On 4/12/2020 6:38 PM, NW Mailing List wrote:
> Attached is a PDF of an article entitled **Virginian 100 Car Test
> of Automatic Straight Air Brake,** from Railway Age, vol. 65, July 26,
> The title of the article itself raises a problem. How can a train
> brake system at once be both **automatic** and **straight air** ?
> Those two terms are mutually exclusive when to comes to air brake lingo.
> The article states that the equipment was manufactured by the
> Automatic Straight Air Brake Company. Now, why would anyone in his
> right mind combine mutually contradictory terms in the name of his
> So, what was special about the brake equipment which was being tested
> The cars were outfitted with the K-2 triple valve, which was the
> industry standard in 1918. Type K brake equipment had come out in the
> 1890s and was only supplanted by the AB brake equipment in the 1930s.
> So, what is different with this train?
> One hint may be in the mention of the fact that the equipment under
> test could be set up for both Graduated Release and Quick Release
> (**quick release** probably meaning nothing more than a standard
> all-at-once release.) I think this might be the key to what was
> under test.
> Since the 1870s, train air brake equipment, while quite efficient at
> stopping trains, had been plagued with two problems which remained
> unsolved for decades: (1) a brake application could not be partially
> released, termed a **graduated release,** and (2) air pressure
> leakage in the train line caused an application to become stronger and
> stronger, until the train stalled out. (For passenger equipment,
> graduated release was incorporated in the UC control valve equipment,
> which I think came out around 1916, but it was deemed dangerous for
> long freight trains.)
> For the two reasons cited above, prior to Westinghouse's introduction
> of the air brake pressure maintaining feature in the 1950s, the method
> by which trains were handled on long sustained down-hill grades was
> with a method called Cycle Braking. In Cycle Braking, an air brake
> application is made, held for a certain period of seconds or minutes,
> then released for a required period of time while the brake system
> recharges (... hopefully.) Then the cycle is repeated: apply for a
> predetermine time period, then release for a predetermined time
> period. And then the cycle is repeated again and again, until the
> train reaches the foot of the grade.
> Most major railroads which operated over long, sustained grades had
> Time Table Special Instructions specifying the particulars of how they
> wanted trains Cycled Braked on their various bad grades. They did not
> leave it to the guesswork of the individual engineman. Also, this is
> why you will find Time Table Special Instructions, which otherwise
> make little sense, requiring that trains stop before entering a
> sustained heavy downgrade, and be gone over by the brakeman or the car
> inspector, looking for leakage, and changing the gaskets or tightening
> the unions as required. Excessive leakage would cause any application
> of the brakes to **leak on** with more force than desired, quicker
> than desired, and the Cycle Braking periods of application/release
> would not work.
> I think the equipment being tested in this article was an attempt to
> address the two air brake conundrums mentioned above: leakage
> stalling out the train, and no provision for graduated release. But
> the article does not state well or clearly how this new equipment
> differed from equipment already in use on the road. And the clowns
> who chose to name their company with a contradiction-in-terms,
> **Automatic Straight Air Brake,** also get a lot of blame for the
> unclarity of this article.
> Perhaps Judge Hensley of Kenova, who fired for Casey Jones and drank
> cognac in George Westinghouse's private car, can concoct a better
> explanation. As for me, I'm done. Mark me off until further notice...
> -- abram burnett,
> Automatic Straight Air Turnips, LLC
> Walton Wye, Va.
> NW-Mailing-List at nwhs.org
> To change your subscription go to
> Browse the NW-Mailing-List archives at
This email has been checked for viruses by AVG.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the NW-Mailing-List