VGN Ry, 100 Car Test Train in 1918

[NW Mailing List]

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.

     WJPowers

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, 
> 1918.
>
> 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 
> company?
>
> So, what was special about the brake equipment which was being tested 
> here?
>
> 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
> http://list.nwhs.org/mailman/options/nw-mailing-list
> Browse the NW-Mailing-List archives at
> http://list.nwhs.org/pipermail/nw-mailing-list/


-- 
This email has been checked for viruses by AVG.
https://www.avg.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://pairlist6.pair.net/pipermail/nw-mailing-list/attachments/20200413/b37b789a/attachment-0001.html>