Union Railroad 0-10-2 Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class U-108b (Locobase 5976)

Data from Ransome-Wallis (1959) and http://www.greenville-pa.com/Web_Pages/Train/G-PI-T-604.htm (4 April 2004) and the DM&IR photo site http://members.lsol.net/mollyandmick/D607.htm (4 April 2004_) and the DM&IR 1960 Locomotive Diagrams book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers 61907-61911 in June 1936 and 62059-62062 in 1937.(Thanks to Chris Hohl for noting the tender booster.)

Locobase doesn't usually include US yard switchers, but makes an exception for this Union class for two reasons: 1) sheer brute size, and 2) its use in transfer service. Well, really it's the size. This was an enormous design, quite suitable for the US Steel railroad on which it operated.

Its unusual arrangement stemmed from the short Union turntables, need for high adhesive weight and power, and relatively short runs. The large firebox -- fitted with three thermic syphons (90 sq ft/8.35 sq m) and a combustion chamber (72 sq ft/6.7 sq m) -- needed a trailing axle and the short turntables and low operating speeds permitted dispensing with a lead truck. Even with the low speeds and relatively tall drivers, each driver set needed substantial counterbalancing. About the only undersized parts were the two 12" (305 mm) piston valves.

The Greenville site says the tender's capacity was about right for a full day's work. To start especially heavy loads, these engines were fitted with powerful tender boosters. These were Franklin Reversible Boosters that operated at 50% cut-off and still delivered over 17,000 lb of tractive effort.

After World War II, the Union bought diesels and sold the Unions to the Duluth, Missabe and Iron Range. "Hot Metal" wrote to the Railway Preservation News forum on 14 March 2013 to report that the booster was removed when they were sold. The DM&IR compensated for the removed booster by adding weight to the locomotive frame.

Most of these operated well into the 1950s. 607, shown on the DM&IR site, was scrapped in 1958, but 604 was returned to the URR for display in 1961.

Specifications by Steve Llanso of Sweat House Media
ClassU-108b
Locobase ID5976
RailroadUnion Railroad
CountryUSA
Whyte0-10-2
Number in Class9
Road Numbers301-309 / 601-609
GaugeStd
Number Built9
BuilderBaldwin
Year1936
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft)22
Engine Wheelbase (ft)32
Ratio of driving wheelbase to overall engine wheebase 0.69
Overall Wheelbase (engine & tender) (ft)67.23
Axle Loading (Maximum Weight per Axle) (lbs)70,000
Weight on Drivers (lbs)364,600
Engine Weight (lbs)422,000
Tender Loaded Weight (lbs)240,000
Total Engine and Tender Weight (lbs)662,000
Tender Water Capacity (gals)12,000
Tender Fuel Capacity (oil/coal) (gals/tons)14
Minimum weight of rail (calculated) (lb/yd)122
Geometry Relating to Tractive Effort
Driver Diameter (in)61
Boiler Pressure (psi)260
High Pressure Cylinders (dia x stroke) (in)28" x 32"
Tractive Effort (lbs)90,893
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.01
Heating Ability
Firebox Area (sq ft)414
Grate Area (sq ft)85.25
Evaporative Heating Surface (sq ft)4808
Superheating Surface (sq ft)1389
Combined Heating Surface (sq ft)6197
Evaporative Heating Surface/Cylinder Volume210.83
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation22,165
Same as above plus superheater percentage27,041
Same as above but substitute firebox area for grate area131,321
Power L122,462
Power MT679.10