New Haven 4-4-2 "Atlantic" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class F-1 / H-1 (Locobase 8115)

Data from NH 1962 Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Delivered as saturated-boiler locomotives in 1907, these Atlantics soon underwent an overhaul in 1912-1922 that added a superheater to the essential 4-4-2. Comparing the F-1 to the A-3 illustrates the signficant gains made by adopting that trailing axle. The grate area almost doubled and heating surface area jumped, which allowed fast running for longer stretches or with heavier trains.

Yet on the New Haven, as on almost all Atlantic operators, the appeal of a still larger boiler and more adhesion led to the class's eclipse in favor of the 4-6-2. New Haven's calculation of boiler underscored the difference. Total evaporation capability came to 35,495 lb/hour of which 11,715 lb/hour was generated by the direct heating surfaces; the latter included 28 sq ft in 4 arch tubes.. Maximum steam consumption reached 34,420 lb/hour, which yielded a boiler factor of 102%.

The F-1 was redesignated H-1 in 1928 to avoid confusion with an inherited CNE 2-8-0 class (Locobase objects: why didn't the foreign-road locomotives recede?) Drury (1993) notes that a couple were kept on the ready after 1935 to substitute for the diesel-powered Comet that ran between Boston and Providence. The last of the class was retired in 1947.

Principal Dimensions by Steve Llanso of Sweat House Media
ClassF-1 / H-1
Locobase ID8115
RailroadNew Haven (NYNH&H)
Number in Class12
Road Numbers1100-1111
Number Built12
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 7.25 / 2.21
Engine Wheelbase (ft / m)28.17 / 8.59
Ratio of driving wheelbase to overall engine wheebase 0.26
Overall Wheelbase (engine & tender) (ft / m)56.08 / 17.09
Axle Loading (Maximum Weight per Axle) (lbs / kg)53,570 / 24,299
Weight on Drivers (lbs / kg)106,720 / 48,407
Engine Weight (lbs / kg)206,200 / 93,531
Tender Loaded Weight (lbs / kg)130,000 / 58,967
Total Engine and Tender Weight (lbs / kg)336,200 / 152,498
Tender Water Capacity (gals / ML)6000 / 22.73
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)14 / 12.70
Minimum weight of rail (calculated) (lb/yd / kg/m)89 / 44.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)79 / 2007
Boiler Pressure (psi / kPa)190 / 13.10
High Pressure Cylinders (dia x stroke) (in / mm)22" x 26" / 559x660
Tractive Effort (lbs / kg)25,726 / 11669.13
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.15
Heating Ability
Firebox Area (sq ft / m2)213 / 19.80
Grate Area (sq ft / m2)53.50 / 4.97
Evaporative Heating Surface (sq ft / m2)2686 / 249.63
Superheating Surface (sq ft / m2)538 / 50
Combined Heating Surface (sq ft / m2)3224 / 299.63
Evaporative Heating Surface/Cylinder Volume234.81
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,165
Same as above plus superheater percentage11,893
Same as above but substitute firebox area for grate area47,350
Power L118,792
Power MT776.41

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Wes Barris