> I like that (Walter V. Turner was probably
> rotating in his grave).
>
> After reading up on 8-ET/8-EL, I think it's the
> other way around. My friend says 8 is even worse
> to maintain than 24.

Wilson wouldn't be amused about my opinion of ABDW. Since 8 came first, 24 should be the hangover. Not sure what you call 22, but I always likened it somewhat to 24. The whole Decelostat with the F1864 relays suggests more drinking was responsible.
>
> >26L is my favorite to run and repair
>
> You go this right. I've heard from people in the
> industry that 24 (for pass cars) and 26 was the
> result of trying to cut down on the man-hours
> required for maintenance. U-12 valves have some
> ports in their slide valves, the sole purpose of
> which is to increase the friction between the
> slide valve and seat when the piston has moved
> part way.
>

"24 (for pass cars)" - did you mean 22?

As I recall, U12 does use a port to control the air acting on the bottom of the slide valve to change its sensitivity in some positions. I heard that Wabco had promoted the U12 to become standard for both freight and passenger use, but either NYC or Pennsy (I don't remember which) refused the idea and since they had a substantial percentage of the US freight car fleet at the time the idea failed.

There was an effort to convert the service piston on AB to diaphragm, (ABC?) but I only saw the remains of one (missing the retaining ring). I assume that it was not cost effective, as it did not catch on. Wabco did build on set of 25, 24 converted to piston valve. Supposed to be one set installed on a loco for one trip before being considered a failure.

I am reasonably sure the original 26 actually came out of the transit side. A friend found an early 26 control valve with a release rod connection on the bottom cover plate. I found a transit parts list for a 26 (no suffix!) engineer's valve, a little primitive but clearly recognizable. It is believed the first 26 systems were used on some early train-set designs (Aerotrain?), should be in the early-mid 1950s.

It is amusing that EMD considered an A-1 charging cut off as an option, but listed the P2A as standard. I consider getting the brake valve cut off in emergency a priority considering the high brake pipe capacity of the 26 system.

> >- but you have to understand it.
>
> Let the air out of the pipe, and the brakes apply?
> ;>)


Only if the auxiliary reservoirs have enough air in them!

> Let the air out of the pipe, and the brakes apply.
> Simple -- haven't gotten it down to any fewer
> words. Physics?? It's the universal gas law, which
> is a combination of Charles's Law, Gay-Lussac's
> Law, and Boyle's Law (also throw in Avogadro's
> Law).

And then there are those that don't think the laws of physics apply to them and realize too late ...


> Right now it's dark, but it's neither cold nor
> raining. My keyboard works jut fine, so I had to
> resort to a brewski or three to have fun.

My ancestors are from Kentucky and Tennessee - I prefer something stronger than barley pop. You can't imagine how much trouble I had trying to get BN to take a carload of beer back. Anheuser-Busch refused the "empty" we spotted them as it was still full of someone else's beer. BN's kept saying - "The computer says it was released empty."