Re: brakes

Schuyler Larrabee

Thanks, Dave, and thanks particularly for that link.  That merits some careful reading, I’m sure.




From: <> On Behalf Of Dave Parker via
Sent: Saturday, June 13, 2020 7:08 PM
Subject: Re: [RealSTMFC] brakes



There is some conflicting information out there with respect to exact dates (e.g., the NMRA info looks suspect), but I tend to rely on the 1913 Westinghouse handbook for information about K brakes:

My understanding is that Westinghouse came up with the "quick-action" triple valve in 1887 (replacing the "plain" valves), and rapidly cornered the marked on air-brake equipment. The first such triple was the "H" valve (H-1, H-2), which was the superseded by the "K" design sometime around the turn of the century (I can't find the exact date with a quick search).  These were just Westinghouse model designations, but they were the de facto industry standard, which is why you see "K-2 Triple" (or K-1) stenciled on so many pre-1927 cars.

In case the clinic didn't cover it, the K-1 valve was for use with 6- and 8-in diameter cylinders, while the K-2 was paired with 12-in cylinders.  KC was short for "cylinder and reservoir Combined", and KD for "cylinder and reservoir Detached".

Hope this helps with the K side of your questions.  I'll leave AB to someone who who models in that era.
Dave Parker
Swall Meadows, CA

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