Yard Air Supply Tanks

Discussion in 'Right of Way' started by mark, Mar 31, 2021.

  1. mark

    mark Member

    Our friend John Peluso in the St. Louis area is looking for detailed drawings, diagrams or plans for yard air supply tank installations on the Frisco.
    This inquiry was prompted by a post on the Frisco Archive. Please see the following: http://frisco.org/mainline/2021/02/17/4-8-2-1522-20/#comment-4321.

    I have searched for plans but have not been able to locate any to date. I am not sure that any formal plans exist but want to use all of our resources to try and answer John’s inquiry.

    The Frisco took great pride in its creative and skilled workers. They often innovated, used resources at hand and developed unique solutions to problems. The yard air supply tank installations I remember in larger terminals in Memphis, Springfield and Tulsa appeared to have been constructed from former steam locomotive, and possibly retired shop, air reservoir tanks mounted in angle iron frames. Most had an arched or shallow pitched roof type cover. They sat just off the ground on small concrete foundations.

    The recycled air reservoirs ran the gamut including tanks with nearly flat, convex or concave ends, some inset, in both riveted and welded configurations. Tanks generally were set in a horizontal configuration along their length. There were installations with single, double, quad and six primary air tanks. The clusters with a larger number of tanks were typically installed with 2 x 2 and 2 x 3 tanks stacked vertically. The multiple tank configurations were plumbed together for a continuous air flow from one to another. Smaller inline moisture tramps were often included.

    Compressed air was supplied from compressor pumps in diesel shops, large repair in place (RIP) tracks, central power houses (Springfield) or individual compressor buildings. Air was plumbed in pipes both underground and by overhead lines. Overhead lines were often hung from “T” shaped scrap rail towers. The equipment was typically painted silver. For improved visibility overhead support towers were often painted a contrasting safety yellow on the lower portion between 6’ and 10’ high.

    Typical plumping included an inlet and outlet shutoff valve on the supply lines before the first and after the last tank. Plumbing ran in one tank end, out the other end to the next tank, in a continuous flow line. Most individual tanks featured a small manually operated moisture drain valve near the tank bottom. Pressure relief valves were typically located on the tank top. Installations were stenciled in black to include periodic testing updates stating “Tested xx/xx/xx” or similar date wording.

    Below are links to additional photographs that show several yard air supply tank installations.

    Example of six tank (2 x 3) installation with arched or curved roof (left of locomotive): http://frisco.org/mainline/?s=wichita#jp-carousel-38002

    Example of a six tank (2 x 3), plus additional tank(s) installation with no roof (left of the locomotives): http://frisco.org/mainline/wp-conte...phis-Tennessee-in-December-1980-Lon-Coone.jpg

    Example of a six tank (2 x 3) installation with peaked roof and side “X” shaped cross bracing (right of locomotive): http://frisco.org/mainline/wp-conte...-Oklahoma-on-August-19-1973-Phillip-Faudi.jpg

    Example of a single tank installation with no roof with several moisture traps (in the foreground): http://frisco.org/mainline/wp-conte...-Tennessee-on-September-1-1980-P.B.-Wendt.jpg

    Example of a six tank (2 x 3) installation with peaked roof and side “X” shaped cross bracing (right of the locomotive): http://frisco.org/mainline/wp-content/uploads/2017/02/GP35-731-at-Memphis-Tennessee-

    Example of a riveted, inset end, single tank with no roof (near the locomotive pilot): http://frisco.org/mainline/wp-conte...-Louis-Missouri-on-July-21-1962-Al-Chione.jpg

    Example of large vertical riveted tank and compressor building: http://www.frisco.org/shipit/index....g-and-air-receiver-at-the-yard-in-mobile.269/

    It was common to locate the tank installations near the ends of the yard receiving and departure (R&D) tracks. Plumbing ran underground to the distribution outlets beside each R&D track, typically in a ground level box. Connected to the distribution outlet was a length of flexible hose that terminated in a valve with glad hand connection. These could in turn be connected to the train line of a cut of cars to supply air to pump up the train’s consist brake system in advance of adding the locomotives.

    An advantage of pre-charging the train line and individual car’s brake systems was to pretest the system for air leaks. If needed repairs could be made. Once the locomotives were added an expedited brake set and release test could be performed before the train’s departure. This reduced the terminal delay associated with charging the train line directly from the locomotives alone, and then if needed making any repairs.

    Ultimately, this helped to expedite movements, while maximizing resource usage, primarily track availability and train crew on duty time. This in turn improved train performance, while at the same time reduced possible delays and associated expenses.

    My suspicion is that these installations were fabricated in house with minimal, if any, formal plans. Shop crews often fabricated relatively simple stuff from rough ideas, or paper sketches at best. However, additional knowledge and other resources may be available.

    To this end, hopefully other Frisco folks will have additional information, photographs, plans or sketches to contribute.

    Hope this helps.


    klrwhizkid and Ozarktraveler like this.
  2. mark

    mark Member

    klrwhizkid and Ozarktraveler like this.
  3. geep07

    geep07 Member

    What can I say!
    This is fabulous investigative research to a very small function that most of us model railroaders knew/know little about.
    Going to my scrap box and compile parts to build one.
    Again, Thank You for your effort!

    Ozarktraveler likes this.
  4. I can remember a dinner table discussion with my dad - he was complaining about the "air-up" time necessary to get big drags out of Springfield. His complaint was mostly based on the relatively small compressor capacity of a set of locomotives - and the demand of filling a long train. At the time I was vacationing from my job which at the time was building big blasthole drills for mining operations. To provide huge CFM output we were using 400 Hp, 480V screw compressors. The photos above don't really show enough receiver capacity to deal with the demand. I suggested that he look into rigging up a big booster compressor that could make a lot of volume in a big hurry. Are there installations like that around the Frisco yards? We discussed using big propane tanks as a source of multiple pressure vessels.

    Are the smaller air stations providing air to start "dead air tank" locomotives? At mines where I've worked, a 240 ton haul truck with an empty air receiver would have to be jumped from another truck - or in the Arctic, with a regulated nitrogen bottle.
    Last edited: Apr 3, 2021
    Ozarktraveler likes this.

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