Baltimore & Ohio 2-8-8-0 "Consolidation Mallet" Type Locomotives

Class Details by Steve Llanso

Class EL-1/EL-2/EL-3/EL-5 (Locobase 439)

Alvin F Staufer & Lawrence W Sagle, B & O Power (1964). Data from Record of Recent Construction #91 (Baldwin Locomotive Works, 1918), p.32-33; see also DeGolyer, Vol 55, pp. 389+.

Baldwin works numbers were:

EL-3

1916

January 42832; February 42854-42855; March 43047-43049, 43071-43073; April 43140, 43148-43150, 43275; May 43289

1917

July 45989; August 46112, 46164; September 46267, 46406; October 46677, 46713; December 47282, 47391, 47489

1918

January 47650; February 47746, 47852, 47950; March 48026, 48067, 48130, 48194; April

48277-48279; May 48577, 48682; June 48901, 48902, 48940, 49086-49087; July 49308, 49400; August 49545

EL-5

1919

September 52371, 52425; November 52464-52468, 52518-52520, 52552-2555, 52598-52605; December 52642-52645

Baldwin reported that these huge locomotives were intended for the 2.4% grades in the Cumberland Division, over which they would haul long, loaded trains of coal cars.

The cylinders used a combination of 14" (356 mm) piston valves for the HP cylinders actuated by Baker gear and Allen balanced slide valves for the LP cylinders operated by Walschaert's gear. When the LP cylinders were rebuilt with piston valves, they were opened by Baker gear. (Thanks to Chris Hohl for providing an example of the weird-looking result.)

Four arch tubes contributed 35 sq ft (3.25 sq m) to the firebox heating surface area.

Definitely intended for main-line service, these big articulateds were able to negotiate curves as sharp as 22 deg. Total weight distribution varied by only 1,100 lb between the front and rear engine units.

Several classes beginning with 15 EL-1 (1916) and followed by 15 EL-2 (7200-7214 in 1916), 30 EL-3 (7115-7144 in 1917) and 26 EL-5 (7145-7170 in 1919-1920) -- all by Baldwin.

All surviving locomotives were converted from 1927 on after the prototype demonstrated a considerable improvement in pulling power; see Locobase 305.

The last of these left service in 1954.

Class EL-3a/EL-5a (Locobase 305)

Data from tables in 1930 Locomotive Cyclopedia.

These were B&O rebuilds of B&O compound Mallets (Locobase 439) to four-cylinder simple-expansion machines beginning in 1927. 64 engines were converted altogether, all to the same powerful standard.

Compared to the EL-6a conversion (Locobase 3556), these locomotives didn't work quite so hard, but steamed as easily. All four cylinders used 14" (356 mm) piston valves.

Smaller drivers undoubtedly confined them to hill work, where they served until the early 1950s.

Class EL-6a (Locobase 3556)

Data from Wiener (1930) supplemented by B&O to 1954 Assorted Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. (Thanks to Chris Hohl for correcting the valve gear ID.)

These were simpled conversions of SAL 2-8-8-2s (Locobase 15148) that had come onto the B&O in 1922. They had a relatively high driver diameter and a hard-worked, but relatively free-steaming boiler. The last of these left service in 1954.


Specifications by Steve Llanso
ClassEL-1/EL-2/EL-3/EL-5EL-3a/EL-5aEL-6a
Locobase ID439 305 3556
RailroadBaltimore & Ohio (B&O)Baltimore & Ohio (B&O)Baltimore & Ohio (B&O)
CountryUSAUSAUSA
Whyte2-8-8-02-8-8-02-8-8-0
Road Numbers7100-71707100-71707300-7315
GaugeStdStdStd
BuilderBaldwinB & OB & O
Year191619271922
Valve GearBaker or WalschaertBaker or WalschaertSouthern
Locomotive Length and Weight
Driver Wheelbase15.50'15.50'15.46'
Engine Wheelbase50.33'50.33'53.33'
Ratio of driving wheelbase to overall engine wheebase 0.31 0.31 0.29
Overall Wheelbase (engine & tender)82.61'82.61'98.27'
Axle Loading (Maximum Weight per Axle)58000 lbs61300 lbs
Weight on Drivers462500 lbs459400 lbs456700 lbs
Engine Weight485600 lbs484400 lbs492000 lbs
Tender Light Weight206400 lbs262000 lbs219000 lbs
Total Engine and Tender Weight692000 lbs746400 lbs711000 lbs
Tender Water Capacity12000 gals18000 gals12000 gals
Tender Fuel Capacity (oil/coal)20 tons18 tons20 tons
Minimum weight of rail (calculated) on which locomotive could run96 lb/yard96 lb/yard95 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter58"58"63"
Boiler Pressure210 psi210 psi225 psi
High Pressure Cylinders (dia x stroke)26" x 31" (2)24" x 32" (4)25" x 32" (4)
Low Pressure Cylinders (dia x stroke)41" x 31" (2)
Tractive Effort91993 lbs113452 lbs121429 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.03 4.05 3.76
Heating Ability
Firebox Area393 sq. ft341 sq. ft398 sq. ft
Grate Area88.17 sq. ft88.17 sq. ft88 sq. ft
Evaporative Heating Surface5836 sq. ft5784 sq. ft5922 sq. ft
Superheating Surface1415 sq. ft1415 sq. ft1380 sq. ft
Combined Heating Surface7251 sq. ft7199 sq. ft7302 sq. ft
Evaporative Heating Surface/Cylinder Volume306.36172.60162.87
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation185161851619800
Same as above plus superheater percentage222192221923562
Same as above but substitute firebox area for grate area9903685932106565
Power L188001225113210
Power MT335.58470.33510.15

Photos

Reference

Credits

Introduction and roster provided by Richard Duley. Class details and specifications provided by Steve Llanso of Sweat House Media.