This is by no means "the last word" on this subject.
But generally, much of the smaller power did not have a triple valve on the locomotive.
Tender yes, engine no. Only straight air on the engine and carried thru to the tender brakes. The tender air brakes worked with both independent (straight) and automatic via use of a double check valve.
As for the RGS, don't' know when they applied triples to the small power (RGS 20 for example).
If I were to venture a guess, during the '40s when more of the excess air brake equipment became avaiable due to old power being scrapped on the standard gauge. Again, this is only a guess on my part.
I would be surprised if any of the RGS C-16's ever had engine mounted triples.
Whe that air brake equipment was added, they used a plain triple (G-24 or F-1) mounted to an auxilary reservoir (10" x 33") by a heavy pipe nipple and 'crow foot' support, under the right side cab floor. Do not mistake the smaller air reservoir that is always present in the same location. That would be the equilizing reservoir used with the G-6 automatic brake valve.
Since there apparently are few mechanical files from eith the Grande or the Southern extant, it is hard to say how many, if any engines had the additional air brake 'betterment' added.
Obvious, RGS 20 & DRGW 318, (that same equipment was added to the 346 during the early '60s).
Does anyone know if the 268, 278, 223 or 315 have the added plain triples & reservoirs?
As for the independent brake valves, The S-3 was standard with the G-6, which was all pasrt of the A-1 brake schedule that was added when the conversion from old 3-way straight air was made. As far as I know, the older power went right to the A-1 equipment when the conversion to automatic air was made.
Also, the larger K engines, including the (I belive) the 36's & 28's when they came from the builders had A-1 equipment. But I have not been able to determine if the engines were equipped with a triple & reservoir on the engine.
As for the K engines, the upgrade to 6-ET took place during the 40's when, as mentioned before, because the older, small main line power was coming out of service to be scrapped.
If it were not for a few interested men, those conversions might never have been made. And since the K engines were the "main power" that got the betterments first, as the C engines were on their way out, few of them got the upgrades.
Some of the older pictures (Otto Perry) of the smaller power should confirm this.
Research anyone?
Lotsa words, and to think you only needed a short answer.
Chris
