Baltimore & Ohio Duplex Drive Locomotives

Class George H. Emerson (Locobase 351)

This unusual "4-8-4" was actually a duplex drive on a rigid wheelbase (unlike articulated or Mallet-type locomotives). The result was a 4-4-4-4; the front set were arranged conventionally, the rear set were reversed. Note the small piston diameter, the oddball stroke, and the high boiler pressure generated by the Emerson water-tube boiler. This was the only B&O engine with duplex drive; see Pennsy Q1, Q2, S1, and T1 classes for other examples.

Specifications

Class George H. Emerson

Locobase ID 351

Railroad Baltimore & Ohio (B&O)

Whyte 4-4-4-4

Road Numbers 5600

Gauge Std

Builder B & O

Year 1938

Valve Gear Walschaert

Locomotive Length and Weight

Driver Wheelbase 19.75'

Engine Wheelbase 48.54'

Ratio of driving wheelbase to overall engine wheebase 0.41

Overall Wheelbase (engine & tender) 89'

Axle Loading (Maximum Weight per Axle)

Weight on Drivers 240300 lbs

Engine Weight 391550 lbs

Tender Light Weight 350000 lbs

Total Engine and Tender Weight 741550 lbs

Tender Water Capacity 22000 gals

Tender Fuel Capacity (oil/coal) 23 tons

Minimum weight per yard of rail on which locomotive could run 100.12 lb rail

Geometry Relating to Tractive Effort

Driver Diameter 76"

Boiler Pressure 350 psi

Cylinders (dia x stroke) 18" x 26.5" (4)

Tractive Effort 67219 lbs

Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.57

Heating Ability

Firebox Area 677 sq. ft

Grate Area 80 sq. ft

Evaporative Heating Surface 4897

Superheating Surface 1312

Combined Heating Surface 6209

Evaporative Heating Surface/Cylinder Volume 313.71

Computations Relating to Power Output (More Information)

Robert LeMassena's Power Computation 28000

Same as above plus superheater percentage 33916.57

Same as above but substitute firebox area for grate area 287019.00

Power L1 57057.57

Power MT 2093.89

Specifications
Class	George H. Emerson
Locobase ID	351
Railroad	Baltimore & Ohio (B&O)
Whyte	4-4-4-4
Road Numbers	5600
Gauge	Std
Builder	B & O
Year	1938
Valve Gear	Walschaert
	Locomotive Length and Weight
Driver Wheelbase	19.75'
Engine Wheelbase	48.54'
Ratio of driving wheelbase to overall engine wheebase	0.41
Overall Wheelbase (engine & tender)	89'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers	240300 lbs
Engine Weight	391550 lbs
Tender Light Weight	350000 lbs
Total Engine and Tender Weight	741550 lbs
Tender Water Capacity	22000 gals
Tender Fuel Capacity (oil/coal)	23 tons
Minimum weight per yard of rail on which locomotive could run	100.12 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	76"
Boiler Pressure	350 psi
Cylinders (dia x stroke)	18" x 26.5" (4)
Tractive Effort	67219 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	3.57
	Heating Ability
Firebox Area	677 sq. ft
Grate Area	80 sq. ft
Evaporative Heating Surface	4897
Superheating Surface	1312
Combined Heating Surface	6209
Evaporative Heating Surface/Cylinder Volume	313.71
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	28000
Same as above plus superheater percentage	33916.57
Same as above but substitute firebox area for grate area	287019.00
Power L1	57057.57
Power MT	2093.89

Credits

Introduction and specifications provided by Steve Llanso of Sweat House Media.