Air Brake Condensate Correction
NW Mailing List
nw-mailing-list at nwhs.org
Tue Dec 29 09:31:31 EST 2020
Asked if I could fix a typo, but it had already gone to the list.
But in the 5th paragraph, he meant to type “26” instead of "24”
So, let the record be corrected.
> On Dec 29, 2020, at 5:37 AM, NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> Herr Holben asks about how the railroads handled condensate in train brake pipes.
> If you read old Time Table Special Instructions (and I hope you do,) you will read the requirement to blow out the brake pipe when re-coupling an engine to its train in cold weather.
> Steam engines, Dismal-engines and ground air plants all had/have a pipework radiator for passing hot air off the compressor through pipe cooled by ambient air temperatures. Condensate drains to the lowest point and is frequently drained away by a blow-down valve, either manually or automatically operated. If you listen to these modern Dismal engines, you will bear the main reservoirs blowing down periodically in short spurts.
> Up into the 1960s, alcohol was added to brake pipes in freezing weather, almost always at the coupling between the engine and first car. We could usually smell it back at the caboose, even on a very long train, if the bleed rod were pulled or the angle cock or conductor’s valve were opened. Every car inspector's shanty had alcohol available, and at every interlocking with air switches, the signal maintainer kept a supply of alcohol (... er, the not-for-drinking type.)
> Things changed after Neoprene diaphragms came into use with the style ABDW triple valve on cars in the 1960s, and in the 24 brake valve on engines. Alcohol was determined to cause failure of the Neoprene diaphragms, which often developed pinholes, causing leaky pressure maintaining features on locomotive brake equipment. At that point, Westinghouse Air Brake came out with some kind of brake pipe anti-freeze liquid which was touted as being non-deleterious to the equipment. You will have to ask someone else about the action of this compound, as I never researched the chemistry. (BTW, the letter W, added to the name of the ABD brake valve when the change was made, stood for Wilson; its inventor was Richard Wilson of Westinghouse Air Brake.)
> Just for fun, attached is a photograph of one of the small copper cans which used to be carried by Car Inspectors back in the day when they added alcohol to brake pipes.
> This one came from the Car Foreman’s Office at Shaffers Crossing. Senator Hamilton of the Mechanical Department saith this is the Ye Perfect Hip Flask and asks if we can ship a dozen immediately...
> -- abram burnett
> Has-Been Brakezmun, Now Medicine-Man of the Turnip Patch
> <Car Inspectors Trainline Alcohol Can_West Roanoke_ca 1968.jpg>________________________________________
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