So there is a debate on another forum about what the tank sitting atop the pilot is for. Maybe Don or someone can shed light on it a bit. Some say extra air reservoir, I dont know about that. I see an air tank under the walkway.
I think it was indeed an extra air reservoir. Thinking at that time for longer trains and/or steep/long grades was the bigger the air reservoir, the better. I suspect there's some truth in that, too. However, one could exceed the ability of the compressor(s) to recharge such voluminous reservoirs under service applications. (Hence the double air compressors.) Andre
In addition to the large tank, the front piston appears to be larger than the trailing piston. I also observed the headlight appears to be missing. Could be ready for the torch cutters.
Collias' Frisco Power has a different photo of 2001 with the aforementioned air reservoir: this one has it stored outside the Birmingham roundhouse in 1935, and he only adds this: "Obvious visible changes made to the mallets were...the addition of a huge 42-inch air reservoir on the pilot deck - a feature more generally associated with the Pennsylvania Railroad's ponderous N-1 class 2-10-2s. All of these changes were accomplished as the engines were pulled from freight service in Missouri and Kansas and placed in mine work in the Alabama coal fields between Birmingham and Sipsey in the mid 1920s." It still doesn't answer the why, but it does address the when, i.e. when the Mallets were moved to Alabama to finish out their remaining days. As a side note, I was going back through some of the past Mallet posts on the site here, and saw at least one mention by Karl of the Mallet's Street Locomotive Stoker system. Seeing pictures of it in Frisco Power remind me of what a cumbersome, unaccountable freak it was.
Thanks for all the replies so far. Looks it was an extra reservoir. It looked kinda cool to me. That dinky little tender was kinda odd for such a large engine.
I still think it was a cool looking locomotive, and innovative, lets us remember it was well over 100 years ago. As Don might tell us, a later designed steam loco might have close to the same tractive effort. Think the 2-10-0 had a similar sized tender. Did any brass builder build a similar locomotive?
Nothing I've seen would work out of the box. There are quite a few USRA 2-8-8-2's that could be modified, but the tender, pilot mounted air reservoir, domes, etc. are all pretty unique on the Frisco 2-8-8-2. There might be a model of an eastern road that I'm not familiar with, but nothing comes to mind.
To be sure, I am a devoted apologist for the 2001-class locomotives. Designed for the 2.3% grades of Dixon Hill, these locomotives suffered train handling issues with the longer trains on the steep grades; the Frisco very quickly moved them to SE Kansas, where they ably handled coal trains and to Sapulpa, where they ably handled oil tank trains. They also found work on the Frisco's Ozark Division between Springfield and Thayer. Later they found work on the Southern Division between Armory and East Thomas Yard. The FEM’s report that while in the Birmingham area, these locomotives were handling trains from the “coal branches” of 60-70 cars at 70 tons per car. These branches, the Empire Branch (Dora (Bergens)- Sipsey), the Kershaw Branch (Samoset to Kershaw), Branch A, and Branch B from Samoset to mines, required empties in and heavy loads out. It was this work with 60 or 70 car trains that required the "extra air" to keep things from running away. The Frisco didn't acquire the Brilliant Branch until 1955. The Frisco gave the Mallet’s a Cooper’s rating of E-50, which was the same as 1040-class Pacifics, the 1281-1305 class Consolidations, and the 1306-1345 class Consolidations, which were in mainline use at the time. Thus, the Mallets were capable of working on all of the Frisco main routes and several branch lines. Indeed, it was their relatively light axle loading that permitted these engines to work the Birmingham-area coal branches. The locomotives finished their careers in the Birmingham, AL area, and the Frisco retired them all by 1939. As might be expected, the locomotives that were equipped with the LP piston valves were the last to go. 2001: April 1939, Birmingham 2002: July 1935, Birmingham 2003: July1935, Birmingham 2004: April 1939, Birmingham 2005: December 1929, Springfield; another source notes early 1928 2006: July 1935, Birmingham 2007: April 1936, Birmingham The attached spread sheet comes from steamlocomotives.com; I have amended it from Frisco diagrams (1918) and from Railway and Locomotive Engineering Magazine. The spreadsheet is an attempt to compare the Frisco Mallets with their contemporaries.
Thanks for adding that bit, Karl - feel like that's a big missing piece for me, vis-a-vis the ginormous air reservoir. The spreadsheet is something like; it's interesting to compare the Frisco's Mallets to others.
