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New Member
I noticed on the front platforms of the ES44DC's BNSF assigns as the Marias Pass helpers there is a gray box mounted to the handrails, with the trainline air hose of the locomotive hooked into it.

I can't see close enough to tell what else is connected to it.

Here's a link to a photo: (not my photo, hope it's OK to link to it)

So, what is it?

We're heading up to Marias Pass this summer, but I just can't wait until then to find out.


"Loco" motive engineer
It's Helperlink. It allows the helpers to cut off in motion when the train gets to the top of the hill. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to - An online railroad bookstore featuring a curated selection of new and used railroad books. Railroad pictorials, railroad history, steam locomotives, passenger trains, modern railroading. Hundreds of titles available, most at discount prices! We also have a video and children's book section. - An online model railroad bookstore featuring a curated selection of new and used books. Layout design, track plans, scenery and structure building, wiring, DCC, Tinplate, Toy Trains, Price Guides and more.

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