Western Railroad Discussion > Dowty Retarders

Reading again from Michael Rhode's new book "North American Rail Yards", I was fascinated to read on page 95 that the "Dowty Retarders" in use at UP's Livonia Yard hump have the ability to both retard and accelerate the cars as they pass over them. (???) I googled Dowty Retarders and after reviewing their function, could not see how accelerating the cars was possible. Any ideas? (Great book, by the way...)

The Dowty system was basically a servo hydraulic version of the standard pneumatic retarders,
you'd accelerate the car by doing no braking!

Out

Wikipedia is you friend:

http://de.wikipedia.org/wiki/Dowty-Retarder

Translated through Google translate (poorly, but you get the gist of what it says)

To enable the shutdown of the braking effect of poorly running car or shunting, the retarder can be summarized in bars that can be folded profile-free. A further development of Dowty retarder is the so-Dowty booster that allowed by an active control also accelerating. Immediately after passing through the wheel of the punch is hydraulically lifted and thereby pushed the wheel. Chance this form is used to execute the hump low and to avoid problems with poor passing cars.

Paul Bernath
Crawford, NE

I bought that book 10 years ago. Has it been updated now?

If I might ask a related question about the Dowty Retarders, do they still use them at the UP Roseville CA yard? I remember when it was rebuilt by the UP, it's a different design than most hump yards with a lower hump crest, not as steep of a hump into the bowl yard, and none of the usual retarders. Instead, they use the Dowty Retarders. I also seem to recall the UP had many teething issues with the yard when it was opened up. I haven't heard much in UP having problems keeping up on traffic flowing through the yard there like before the "Great Recession", but imagine that carload traffic is reduced from what it was back then.

Other yards that use these on the UP is Livonia, LA and Interbay, (Seattle) WA on the BNSF. According to the book's first edition, it shows them in use on the BNSF at Lincoln NE, but Google Earth photos now show them replaced with what looks like standard retarders.

cpn456 Wrote:
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> Other yards that use these on the UP is Livonia,
> LA and Interbay, (Seattle) WA on the BNSF.
> According to the book's first edition, it shows
> them in use on the BNSF at Lincoln NE, but Google
> Earth photos now show them replaced with what
> looks like standard retarders.

Yes, Roseville still uses the Dowty retarders. CN's Harrison Yard in Memphis, TN also uses Dowty retarders.

During its modernization, I believe CP's Bensenville Yard had Dowty retarders. Now the hump is closed altogether.

Andrew

Posted from iPhone

LiveWire Wrote:
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> I bought that book 10 years ago. Has it been
> updated now?


North American Railyards, Updated and Expanded Edition Hardcover
Amazon Books
December 2014

Do they all come from China nowadays?:

http://jnhwgk.en.alibaba.com/product/1408328608-219095895/orbital_deceleration_crest_track_dowty_retarder.html

To the Roseville issue, we were the regional Dowty sales and engineering distributor and they wouldn't
let us anywhere near Roseville because of litigation and performance issues. Hopefully they finally
resolved some of those. We had numerous conversations on the application and it always seemed like a
solution out looking for a problem. The pneumatic standard retarders when used properly seemed to be
satisfactory but Dowty's selling feature was a greatly reduced shock and hence claims solution to
humping cars.

Out

callum_out Wrote:
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> The pneumatic
> standard retarders when used properly seemed to
> be
> satisfactory but Dowty's selling feature was a
> greatly reduced shock and hence claims solution
> to
> humping cars.
>
> Out

Touched on in this document:

http://www.regulations.gov/#!documentDetail;D=FRA-2010-0145-0014

TL