Attached is a letter from the Archives mentioning a boiler failure on #4004 circa January, 1952,.

I'd say it's not an Alaska Railroad unit. I'd also say it's a USATC locomotive on Ft. Richardson or Elmendorf. They had several of these and one USATC small drivered Consolidation that they traded to the Alaska RR for one of the 0-6-0s. These weren't on the ARR roster. The railroad apparently did the heavy maintenance on the Army locomotives. I can't find it today, but one of the letters mentions having work (tubes) done in the ARR shops.

One of the letters from the Archives mentions a January,1952 boiler explosion on #4015, another of the USATC 0-6-0s. Two boiler failures within a month? If there isn't a typo in the numbers, bet someone got fired.

Neat photo. It's the first I've seen of one of the locomotives Army owned and operating on the bases.

I've always suspected the little building on Elmendorf AFB just below and left of the stick pin on this map was a small engine house. It's small, but fairly tall and just looks the part. The spur to some warehouses used to run diagonally from the intersection in the upper right of the map  and passed just above the "engine house."  You can see a trace of its path in the open area. The orientation would be just right for a siding to come off of the warehouse spur. The tracks to the warehouses were there when I arrived in 1981 and  were removed in the mid- or late-1980s. There was not track to the "engine house" at that time. By the time I had arrived, the larger building, a satellite communications terminal, had been built and any tracks were probably removed when that building was built. That's the ARR main that crosses Pease.

From Patrick Durand on 2/4/17: I concur with Dick on probable disposition is Fort Richardson.  It could also be Fort Wainwright or Ladd field in Fairbanks.  The engineer is wearing a GI issue winter hat. The army did have their own locomotives just as Eielson AFB does today to handle coal deliveries to their power plant.

From Dick Morris on 2/4/17: Pat is right, it could have also been up north. I don't think the letter arranging for a replacement says where 4004 was located and my impression is that the northern bases were subordinate to Ft. Richardson which may have made arrangements for them.

From Don Marenzi on 2/7/17: I'm away from my files at the moment.  Shooting from memory, including discussions with John Henderson and Bob Barrett about it:

USA 4004 was never transferred to or owned by the ARR.  It was the Army's Fort Richardson switcher.  If I recall correctly there are some photos of it operating on the ARR in Anchorage near/at the depot at the Anchorage Historical & Fine Arts Museum. Maybe it was a troop transfer run to/from  Fort Richardson ?   

The photo you sent appears to be a troop movement too.  I don't know the location but I'd guess it's at  Fort Richardson. The sign on the structure says Q.M. Warehouse (Quartermaster).

I'd assume that any shop repairs would have been done at the Anchorage ARR shop too.  Retired when the Army got the Alco diesel switchers at Fort Richardson.  I'm not sure of the dates it arrived  or was retired.  I'll look for that info.  I seem to recall it was shipped to Seattle along with a batch of  ARR steamers to be scrapped.