The C&EI took up with the Twelve-wheeler concept beginning with this class from Pittsburgh. Drury (1993) explains that the front truck (or bogie) offered more stability for road-freight service. All drivers were equalized together, says LE, and the rear equalizer engaged with a double elliptic spring. Moreover, the type often had bigger boilers. LE reported that the goal was to be able to move the same number of cars in winter as in summer. The Consolidations then in use were rated at 47 loads in the summer, but only 35 in the winter. Naturally, the new engines' performance was described as "more than equal to expectations."
Soon, however, the 2-8-0 grew into the tractive effort and steam-making size of the 4-8-0 and the somewhat ungainly wheel arrangement faded out of favor. All of this class were renumbered in 1911.
They were converted to 0-6-0 switchers beginning in 1916. This meant the deletion of half the axles under the boiler and Locobase is still searching for an illustration of the result. At the time, the engines renumbered together with the slightly later 141s in a jumbled order.
All were discarded and scrapped in July 1934.
Pittsburgh's second batch of Twelve-wheelers for the C & EI had eight fewer boiler tubes for some reason (possibly more strength at the tube sheets?). Otherwise they were identical to the 12 that were delivered two years earlier (Locobase 7130) and were also converted to 0-6-0 switchers in 1916 (1718), 1923 (1720), and 1924 (1719, 1721).
This was the last in a series of five Twelve-wheelers (Locobases 2028-2031) and was obviously an trial horse for compounding. Other than the unusual (for a US engine) two-cylinder layout, this was a conventional locomotive and gave no hint of the camelback of the same arrangement and from the same builder that followed just a year later (see Locobase 3932).
RG gives a confusing summary of heating surfaces in which they add 192 sq ft of firebox to 2,216.7 sq ft of tube heating surface and come up with 2,216.7 sq ft. Given that the later camelback had more and longer tubes, it seems likely that the stated tube heating surface is actually the total including firebox. Indeed, as the diagrams make clear, that was the case. The specifications show the slightly varied heating surface areas.
The original tender
Clearly the Chicago & Eastern Illinois was searching for a heavy power formula. The preceding year had seen a two-cylinder compound on the same 4-8-0 arrangement -- see Locobase 3933.
RG discussed these large twelve-wheeler camelbacks, noting that unlike the eastern railroad engines with wide Wootten fireboxes suitable for burning anthracite culm, these locomotives burned bituminous run of mine coal. Compared to the earlier compound, they had a larger boilers with more and longer tubes. The C&EI calculated the tractive effort as 34,240 lb (15,531 kg).
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Railroad||Chicago & Eastern Illinois (C&EI)||Chicago & Eastern Illinois (C&EI)||Chicago & Eastern Illinois (C&EI)||Chicago & Eastern Illinois (C&EI)|
|Number in Class||12||4||1||7|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||15.50 / 4.72||15.50 / 4.72||15.50 / 4.72||15.50 / 4.72|
|Engine Wheelbase (ft / m)||25.33 / 7.72||25.33 / 7.72||26.17 / 7.98||26.33 / 8.03|
|Ratio of driving wheelbase to overall engine wheebase||0.61||0.61||0.59||0.59|
|Overall Wheelbase (engine & tender) (ft / m)||53.58 / 16.33||53.58 / 16.33||54.50 / 16.61||51.17 / 15.60|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)|
|Weight on Drivers (lbs / kg)||142,000 / 64,410||142,000 / 64,410||146,960 / 66,660||150,000 / 68,039|
|Engine Weight (lbs / kg)||172,000 / 78,018||172,000 / 78,018||185,948 / 84,345||189,700 / 86,047|
|Tender Loaded Weight (lbs / kg)||100,000 / 45,359||100,000 / 45,359||116,800 / 52,980||98,000 / 44,452|
|Total Engine and Tender Weight (lbs / kg)||272,000 / 123,377||272,000 / 123,377||302,748 / 137,325||287,700 / 130,499|
|Tender Water Capacity (gals / ML)||4500 / 17.05||4500 / 17.05||5800 / 21.97||4500 / 17.05|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||10 / 0.20||10 / 0.20||13 / 11.80||10 / 9.10|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||59 / 29.50||59 / 29.50||61 / 30.50||63 / 31.50|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||54 / 1372||54 / 1372||54 / 1372||54 / 1372|
|Boiler Pressure (psi / kPa)||200 / 13.80||200 / 13.80||200 / 13.80||200 / 13.80|
|High Pressure Cylinders (dia x stroke) (in / mm)||21" x 26" / 533x660||21" x 26" / 533x660||21.5" x 30" / 546x762 (1)||21.5" x 30" / 546x838 (1)|
|Low Pressure Cylinders (dia x stroke) (in / mm)||33" x 30" / 838x762 (1)||33" x 30" / 0x0 (1)|
|Tractive Effort (lbs / kg)||36,097 / 16373.34||36,097 / 16373.34||30,648 / 13901.72||30,648 / 13901.72|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||3.93||3.93||4.80||4.89|
|Firebox Area (sq ft / m2)||197 / 18.31||197 / 18.31||197 / 18.31||181.40 / 16.86|
|Grate Area (sq ft / m2)||35.80 / 3.33||35.80 / 3.33||35.80 / 3.33||72 / 6.69|
|Evaporative Heating Surface (sq ft / m2)||2299 / 213.66||2242 / 208.36||2241 / 208.27||2447 / 227.42|
|Superheating Surface (sq ft / m2)|
|Combined Heating Surface (sq ft / m2)||2299 / 213.66||2242 / 208.36||2241 / 208.27||2447 / 227.42|
|Evaporative Heating Surface/Cylinder Volume||220.57||215.10||355.55||388.23|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||7160||7160||7160||14,400|
|Same as above plus superheater percentage||7160||7160||7160||14,400|
|Same as above but substitute firebox area for grate area||39,400||39,400||39,400||36,280|