That's so the loco can use a Tyco uncoupling track;)
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I love this type of shot. . . .So many questions I can ask correctly? Here goes, The line connections on either side of the coupler, what are they? 1. M.R. 2. ACT. 3. A&R . Thank you for the feedback I know will be provided. I can count on you guys!
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Ahhh one of those "once in a lifetime" is enough, moments. I don't want to know more!
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MR is the Main Reservoir, it connects the main reservoirs between all units (130-140 psi) so that all units in the consist have their compressors contributing to the air supply, or conversely if there's a dead unit in the consist the others are supplying air to its main reservoir for braking.
ACT is the actuating (bail off) hose. When the automatic brake is set it applies the independent brakes on the locomotives, depressing the independent brake handle (actuating or "bailing off") keeps the independent brake from applying, which you normally don't want during a normal automatic brake application. Actuating sends signal air through this hose to the other units in the consist to bail off their independent brakes as well. 0 psi when not actuating, and if I remember it's straight main res pressure when actuating.
A&R is application and release. This controls that application and release of the independent brakes on all the units in the consist. As the independent in the lead unit is applied or released signal air is sent through this hose to apply or release brakes on the other units. 0-45 psi, 0 when released, 45 when the independent is fully applied.
It is possible to cross the A&R and ACT hoses if you're sloppy which creates some problems. If you connect the ACT from the leader to the A&R on the trailer, for instance, when you're bailing off the leader it's actually causing the independent brakes on the trailing unit to apply, and actually apply even harder than what they're set for on that unit.
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Main Reservoir ,actuating, application and release.
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Main Reservoir ,actuating, application and release.
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Yet there's still a couple of regular replacement knuckles there too. Hmm. Maybe useful for yard shoves?
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MR - Main Reservoir Hose
Actuating - Bail off Independent Brake
Application and Release - Apply / Release Independent Brake
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That's very similar to the front coupler on the helper engine of a buddies layout. This way the helper can back off without the train having to stop at the top of the helix.
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Jeff, I think you are on to something. Looking at the Google map, it seems that it was in a yard and maybe intended to shove a cut up and over the hump for classification.
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You would need a knuckle in there even if it was for shoving onver a hump (there is not one in Council Bluffs) there would be no way to control your train without it. I have seen many things, but this perplexes me.
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The only guess I could think of is that the enginehouse crews swap the knuckle out for this when moving something with their "shop goat" tractor, which I don't believe has a coupler...but I wouldn't think the tractor could handle a locomotive. The local T&E guys I've heard back from didn't know anything about it, so I think it's safe to say that it's got to be shop-related.
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Very informative. Thank you all for helping me to understand this operation.
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| Posted by Mark on June 4, 2013 | |
Here is an explanation I received from an Iowa Interstate employee:
That coupler is used at our Council Bluffs shop for moving freight car trucks around the shop area. The long piece welded on the knuckle keeps the truck being moved from rolling under the coupler. An innovative idea. People would laugh at you if you tried to model this.
An innovative idea indeed. Shop workers with good tools can solve any problem.
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