Nickel Plate 4-6-4 "Hudson" Type Locomotives

Class L-1a/L-1b (Locobase 188)

Firebox had syphons. Drury's (1993) comment on these engines: They "...looked bigger than they were after the smoke lifters were added. In actuality, they were little more than a USRA light Pacific with a four-wheel trailing truck." A thicker tire (74") more than offset an increase in boiler pressure to 225 psi, so the tractive effort dropped slightly.

Specifications

Class L-1a/L-1b

Locobase ID 188

Railroad Nickel Plate

Whyte 4-6-4

Road Numbers 170-177

Gauge Std

Builder Alco

Year 1927

Valve Gear Baker

Locomotive Length and Weight

Driver Wheelbase 13'

Engine Wheelbase 37.75'

Ratio of driving wheelbase to overall engine wheebase 0.34

Overall Wheelbase (engine & tender) 73.65'

Axle Loading (Maximum Weight per Axle)

Weight on Drivers 175475 lbs

Engine Weight 316500 lbs

Tender Light Weight 206200 lbs

Total Engine and Tender Weight 522700 lbs

Tender Water Capacity 11000 gals

Tender Fuel Capacity (oil/coal) 16 tons

Minimum weight per yard of rail on which locomotive could run 97.49 lb rail

Geometry Relating to Tractive Effort

Driver Diameter 73"

Boiler Pressure 215 psi

Cylinders (dia x stroke) 25" x 26"

Tractive Effort 40681 lbs

Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.31

Heating Ability

Firebox Area 302 sq. ft

Grate Area 66.80 sq. ft

Evaporative Heating Surface 4219

Superheating Surface 1103

Combined Heating Surface 5322

Evaporative Heating Surface/Cylinder Volume 285.61

Computations Relating to Power Output (More Information)

Robert LeMassena's Power Computation 14362

Same as above plus superheater percentage 17338.57

Same as above but substitute firebox area for grate area 78386.93

Power L1 27724.35

Power MT 1044.96

Specifications
Class	L-1a/L-1b
Locobase ID	188
Railroad	Nickel Plate
Whyte	4-6-4
Road Numbers	170-177
Gauge	Std
Builder	Alco
Year	1927
Valve Gear	Baker
	Locomotive Length and Weight
Driver Wheelbase	13'
Engine Wheelbase	37.75'
Ratio of driving wheelbase to overall engine wheebase	0.34
Overall Wheelbase (engine & tender)	73.65'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers	175475 lbs
Engine Weight	316500 lbs
Tender Light Weight	206200 lbs
Total Engine and Tender Weight	522700 lbs
Tender Water Capacity	11000 gals
Tender Fuel Capacity (oil/coal)	16 tons
Minimum weight per yard of rail on which locomotive could run	97.49 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	73"
Boiler Pressure	215 psi
Cylinders (dia x stroke)	25" x 26"
Tractive Effort	40681 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	4.31
	Heating Ability
Firebox Area	302 sq. ft
Grate Area	66.80 sq. ft
Evaporative Heating Surface	4219
Superheating Surface	1103
Combined Heating Surface	5322
Evaporative Heating Surface/Cylinder Volume	285.61
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	14362
Same as above plus superheater percentage	17338.57
Same as above but substitute firebox area for grate area	78386.93
Power L1	27724.35
Power MT	1044.96

Reference

Historic Northern Pacific Steam Photos (Photos courtesy Yesteryear Depot)

Credits

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