Delaware & Hudson 4-6-2 "Pacific" Type Locomotives

Class P (Locobase 3076)

Firebox heating surface includes 40 sq ft of arch tubes.

Because these engines used the big anthracite-burning grate, one can draw a misleading conclusion about this design's ability to steam, particularly in reviewing the A/S ratio of tube/flue cross-section to grate area. Coincidentally, the Railway Age article (14 December 1914) describing these engines makes the point a different way: "According to the method of boiler proportioning used [by Alco], these ...engines have 111 percent boilers." RA explains that 100 percent means ample steam-making capacity, but passenger engines should have some in reserve.

Given the D&H's limited passenger demands these engines were quite worthy and ran until 1952-1953.

http://gelwood.railfan.net/other/dh/dh-stm-bk-html published locomotive diagrams that showed the superheat at 840 sq ft, an increase over the original size.

Class P-1 (Locobase 143)

Although laid out according to orthodox American

design, these three engines had a British look in their clean boilers, thick and wide face shield below the smokebox, and plain smokebox face with headlight centered. Two had poppet valves and one piston valves -- all were experimental and did not lead to large classes.

Data from 1933 D & H Description of Locomotives books supplied in May 2005 by Allen Stanley from his extensive collection.

Specifications
ClassPP-1
Locobase ID3076143
RailroadDelaware & HudsonDelaware & Hudson
Whyte4-6-24-6-2
Road Numbers600-609651-653
GaugeStdStd
BuilderAlco-SchenectadyD & H
Year19141929
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase13'13.50'
Engine Wheelbase34.83'35.30'
Ratio of driving wheelbase to overall engine wheebase 0.37 0.38
Overall Wheelbase (engine & tender)70.35'86.56'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers191000 lbs191000 lbs
Engine Weight293500 lbs300000 lbs
Tender Light Weight135000 lbs160500 lbs
Total Engine and Tender Weight428500 lbs460500 lbs
Tender Water Capacity8000 gals11000 gals
Tender Fuel Capacity (oil/coal)14 tons14 tons
Minimum weight per yard of rail on which locomotive could run106.11 lb rail106.11 lb rail
Geometry Relating to Tractive Effort
Driver Diameter69"73"
Boiler Pressure205 psi260 psi
Cylinders (dia x stroke)24" x 28"22" x 28"
Tractive Effort40729 lbs41027 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.69 4.66
Heating Ability
Firebox Area317 sq. ft320 sq. ft
Grate Area99.32 sq. ft86.94 sq. ft
Evaporative Heating Surface38963208
Superheating Surface8401495
Combined Heating Surface47364703
Evaporative Heating Surface/Cylinder Volume265.74260.41
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation20360.6022604.40
Same as above plus superheater percentage23971.8629789.94
Same as above but substitute firebox area for grate area76511.06109647.80
Power L120970.3646896.19
Power MT726.151623.90

Reference

Credits

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