Chicago & Eastern Illinois 4-8-0 "Mastodon" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 129 (Locobase 7130)

Data from the C&EI 6 - 1904 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also "Twelve-Wheel Locomotive--Chicago & Eastern Illinois Railroad," Locomotive Engineering, Volume 11, No 3 (March 1898), pp. 127-128. Works numbers were 1741-1742 in October 1897, 1743-1745 in November, 1849-1851 in August 1898, and 1852-1855 in September.

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.

Class 141 (Locobase 7131)

Data from the C&EI 6 - 1904 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 2028-2031 in December 1899.

Pittsburgh's second batch of Twelve-wheelers for the C & EI had 8 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).

Class 145 (Locobase 3933)

Railroad Gazette (February 1900 -- Vol XXXII, No 8, p 117) described this two-cylinder compound twelve-wheeler design. Builder information from B Rumary list supplied by Allen Stanley in March 2004. Works number was 2032 in December 1899.

This was the last in a series of five Twelve-wheelers (2028-2031) and was obviously an trial horse for compounding. Other than the unusual (for a US engine) 2-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 record #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.


Class 170 (Locobase 3932)

Data from Railroad Gazette (16 November 1900) and C&EI 6 -1904 Locomotive Diagrams supplied in March 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 2157-2160 in October 1900. Builder information from B Rumary list supplied by Allen Stanley in March 2004.

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 fireboxes, 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).

Specifications by Steve Llanso of Sweat House Media
Locobase ID7130 7131 3933 3932
RailroadChicago & Eastern Illinois (C&EI)Chicago & Eastern Illinois (C&EI)Chicago & Eastern Illinois (C&EI)Chicago & Eastern Illinois (C&EI)
Number in Class12417
Road Numbers129-140/1706-1716141-144/1718-1721145/1705170-174/1700-1704
Number Built12417
Valve GearStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft)15.5015.5015.5015.50
Engine Wheelbase (ft)25.3325.3326.1726.33
Ratio of driving wheelbase to overall engine wheebase 0.61 0.61 0.59 0.59
Overall Wheelbase (engine & tender) (ft)53.5853.5854.5051.17
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)142,000142,000146,960150,000
Engine Weight (lbs)172,000172,000185,948189,700
Tender Loaded Weight (lbs)100,000100,000116,80098,000
Total Engine and Tender Weight (lbs)272,000272,000302,748287,700
Tender Water Capacity (gals)4500450058004500
Tender Fuel Capacity (oil/coal) (gals/tons)60601310
Minimum weight of rail (calculated) (lb/yd)59596163
Geometry Relating to Tractive Effort
Driver Diameter (in)54545454
Boiler Pressure (psi)200200200200
High Pressure Cylinders (dia x stroke) (in)21" x 26"21" x 26"21.5" x 30" (1)21.5" x 30" (1)
Low Pressure Cylinders (dia x stroke) (in)33" x 30" (1)33" x 30" (1)
Tractive Effort (lbs)36,09736,09730,64830,648
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.93 3.93 4.80 4.89
Heating Ability
Firebox Area (sq ft)197197197181.40
Grate Area (sq ft)35.8035.8035.8072
Evaporative Heating Surface (sq ft)2299224222412447
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)2299224222412447
Evaporative Heating Surface/Cylinder Volume220.57215.10355.55388.23
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation71607160716014,400
Same as above plus superheater percentage71607160716014,400
Same as above but substitute firebox area for grate area39,40039,40039,40036,280
Power L15671557339114066
Power MT352.18346.09234.68239.04


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