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

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.

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 design used a combination of 14" piston valves for the HP cylinders and Allen balanced slide valves for the LP cylinders. 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.

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

Class EL-6a (Locobase 3556)

These were simpled conversions of SAL 2-8-8-2s 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.

Wiener (1930) for data.

Specifications
Class	EL-1/EL-2/EL-3/EL-5	EL-3a/EL-5a	EL-6a
Locobase ID	439	305	3556
Railroad	Baltimore & Ohio (B&O)	Baltimore & Ohio (B&O)	Baltimore & Ohio (B&O)
Whyte	2-8-8-0	2-8-8-0	2-8-8-0
Road Numbers	7100-7170	7100-7170	7300-7315
Gauge	Std	Std	Std
Builder	Baldwin	B & O	B & O
Year	1916	1927	1920
Valve Gear	Walschaert		Walschaert
	Locomotive Length and Weight
Driver Wheelbase	15.50'	15.50'	15.46'
Engine Wheelbase	50.33'	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 lbs
Weight on Drivers	462500 lbs	459400 lbs	456700 lbs
Engine Weight	485600 lbs	484400 lbs	492000 lbs
Tender Light Weight	206400 lbs	262000 lbs	219000 lbs
Total Engine and Tender Weight	692000 lbs	746400 lbs	711000 lbs
Tender Water Capacity	12000 gals	18000 gals	12000 gals
Tender Fuel Capacity (oil/coal)	20 tons	18 tons	20 tons
Minimum weight per yard of rail on which locomotive could run	96 lb rail	96 lb rail	95.15 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	58"	58"	63"
Boiler Pressure	210 psi	210 psi	225 psi
Cylinders (dia x stroke)	26" x 31"	24" x 32" (4)	25" x 32" (4)
Tractive Effort	91993 lbs	113452 lbs	121429 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	5.03	4.05	3.76
	Heating Ability
Firebox Area	393 sq. ft	341 sq. ft	398 sq. ft
Grate Area	88.17 sq. ft	88.17 sq. ft	88 sq. ft
Evaporative Heating Surface	5836	5784	5922
Superheating Surface	1415	1415	1380
Combined Heating Surface	7251	7199	7302
Evaporative Heating Surface/Cylinder Volume	306.36	172.60	162.87
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	18516	18516	19800
Same as above plus superheater percentage	22219	22219	23541.99
Same as above but substitute firebox area for grate area	99036	85932	106473.99
Power L1	8800	12251	13210.39
Power MT	335.58	470.33	510.16