> Long before Turner quit being a sheepman and the Santa Fe, Galton, with the help of Westinghouse made several experiments on various British Railways ca 1878. WAB reprinted the papers in the 1890s under Galton's title 'The Effects of Brakes on Railway Trains'
GW built the speed recorder and had his hand on nearly every aspect of the test wagon and the test runs.

Walter V. Tuner was a British mechanical engineer, who came to the US and was working on ranch when he hired on at WABCo in 1903.

The 1878-1879 Galton-Westinghouse tests (made in England) involved wheel-rail adhesion, not the air brake.

>The information from those experiments is still germane

Yes.

>for example
>Don't slide the wheels- sliding friction is less than rolling friction
>For a given shoe pressure braking force is inversely proportional to wheel speed

Yes.

>This has been worked around by the Composite Brake shoe to replace cast iron
>but it was/is a key to high speed braking

Even with composition shoes there is a speed/friction curve, although it's a much flatter one than for cast iron shoes.

>You are correct that air from a broken pipe must exit at the break- however, the wave
>propagation from the pressure change is what sets the other brakes in the train.
>Otherwise the action would be incredibly slow in a long train- like that of straight air,
>and the shocks at the rear end would be lethal

This is the reason why Westinghouse's triple valve designs developed between 1873 and 1886 all failed at the Burlington Trials of 1886. Considerations of air flow rate figured into the 1887 Westinghouse Freight Train Tests' establishing 1 1/4" as the minimum diameter for the brake pipe.

>You are incorrect in saying emergency action in the QA exhausted to the air.

I mistyped: it's QS air pressure which is exhausted to one of three places (BC, ATM, or small reservoir), depending on the type of triple/control valve.

On the other hand, QA is handled quite differently with freight valves beginning with AB and passenger with UC. Some of these use three reservoirs, others four, to accomplish quick action, and none of the airflow involved with operating the quick action feature enters the BC.

There were some 14 prominent air brake trials between the 1878 Newark Tests and the 1912 Absecon Tests (the "second" Absecon tests).

>Also, air acts just like water when you close the angle cock.

Correct, and this is why Westinghouse consistently referred to his air brake apparatus as part of a "fluid power braking system" in his patent applications.

>When you close that angle cock, the air flowing thru the pipe stops and, like water, bounces back the other way. That is how you get a release and the cars roll away. The first car senses an increase and goes into release. That sends a little air into the brake pipe and the next car starts to release and so it goes until the whole train is released.

This is an effect of the way AB control valves are designed to allow pressure from the emergency reservoir to aid in recharging the brake pipe during releases and from both the BC and ER during releases after emergency applications. ABD, etc. doesn't use BC air pressure for this. It's possible for this pressure wave to causes releases with H and K triples, but it's nowhere near as dramatic.