Steam & Excursion > Steam / Diesel MU Question

With all the discussions about diesel helpers with the larger mainline steam trips, I had a question come up. I am 100% positive many on here will know this answer but not me (yet).

When diesels are MU'ed they are connected electrically through an MU cable plus in addition to the brake pipe there are air connections for main reservoir, application and release, and actuating. So, when a diesel helper is "MU'ed" to a steam locomotive such as 4449, 844, 4014, etc., I know there is an MU cable plus obviously the trainline brake pipe. My question is do they also have the three additional hoses for main reservoir, application and release, and actuating, or is there just the MU cable? If these extra hoses were not there the engineer on the steam locomotive would have limited control of the engine brakes on the diesel helper unit(s). Just curious.



Edited 1 time(s). Last edit at 10/23/19 20:13 by Railbaron.

Yes, many, and maybe most, of the steamers capable of controlling diesels are equipped with the MU main reservoir, application and release, and actuating air lines.

I thought I had pictures of the MU hoses on the rear of the SP&S 700's tender but I couldn't find them on my hard drive.  However, I did find pictures that I took of the connections on the front and the rear of our auxiliary tender after I had finished piping them but before they got painted.

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When I was on the steam crew we had all the "mu" connections including the air lines on the tenders of 844 and 3985.
We did not have these conections on the front of the locomotives so when double heading the second steam locomotive would control the diesel if one was in consist.

Bob Krieger
Cheyenne, WY



Edited 1 time(s). Last edit at 10/24/19 06:31 by Bob3985.

As information, UP 4014 does not yet have the diesel MU Box Control installed. However, since the tender is from 3985, all the necessary electrical and air connections are available, as well as on both auxiliary water tenders.

Thank you for your answers; I have no idea why but that question just popped into my head.

Here's a picture from Nomosantafe from a past discussion.

Sorry, I know how to post pictures but never figured out how to posts links to threads. Search for running a diesel helper with steam or something like that.

Doug Wetherhold
Macungie, PA



Edited 1 time(s). Last edit at 10/25/19 02:47 by ALCO630.

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On the Internet I found this picture of the 700 and 4449 tenders sitting side by side showing the MU air hoses on each one.  The 700's main reservior MU hose appears to be folded back over the trainline air pipe.

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