Chesapeake & Ohio 2-6-6-2 Type Locomotives

Class H-1, H-2 (Locobase 440)

First class of the C&O's 2-6-6-2 compound Mallets. The first (H-3) -- 1300, built at Brooks -- was lighter on the drivers (285,000 lb) than her successors and had a smaller boiler. The 1301 was built at Schenectady in 1910 with considerably more heating surface (6,013 sq ft). The design stabilized in the 23 engines were built at Richmond. These had 23 sq ft of arch tube area.

Although the design represented a significant increase in power, their low drivers and small size doomed them to a relatively short life. They were all scrapped by 1935.

Wiener (1930) for data.

Class H-3/H-4/H-6 (Locobase 441)

Data from C&O 9 -1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Firebox heating surface included 25 sq ft of arch tubes. All 175 had 12"-diameter piston valves for the rear, HP cylinders and slide valves for the LP cylinders driving the forward engine set.

150 H-4s were built at Schenectady and Richmond between 1912 and 1918. They diiffered from 24 H-2s of 1911 (Brooks) by 35,000 lb of engine weight each. Individual H-4 batches had adhesion weights ranging from 358,000 to 364,900 lb.

55 H-6s, 45 built by Alco in 1920-1923 and 10 by Baldwin in 1949, rounded out this numerous class. The 25 H-3s were built for the Hocking Valley in 1917-1918 to the same design, but the boilers were pressed to 220 psi, which yielded a slightly higher tractive effort.

(20 H-5s built by Baldwin and Alco were USRA light Mallets.).

The H-2s retired in 1935, the H-4s 1930-1955, and the H-6s from 1952 to 1957.

Class H-5 (Locobase 299)

Data from tables in 1930 Locomotive Cyclopedia and from C & O 9 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Firebox had combustion chamber and 34 sq ft of arch tubes contributed to firebox heating surface. This design was one of two articulated types that formed part of the roster of standardized designs developed for general production in WW I.

These light USRA Mallets weren't very well received. Only 30 were built, 10 by Baldwin, 20 by Alco Schenectady. The Baldwins served the Wheeling & Lake Erie for decades, while the 20 Alcos saw service on the C&O, where they "steamed well and performed satisfactorily." Yet the Chessie didn't like the engines much and picked at the design (poor ashpans, need to reduce steam pressure from 225 to 210 psi, poor cab layout). Eugene Huddleston (Trains, March 1991) contends that the C&O's requirements had outstripped the 2-6-6-2 arrangement and that contributed to the road's disaffection.

Specifications
Class	H-1, H-2	H-3/H-4/H-6	H-5
Locobase ID	440	441	299
Railroad	Chesapeake & Ohio (C & O)	Chesapeake & Ohio (C & O)	Chesapeake & Ohio (C & O)
Whyte	2-6-6-2	2-6-6-2	2-6-6-2
Road Numbers	1301, 1302-1324	1275-1299, 1325-1474	1520-1539
Gauge	Std	Std	Std
Builder	Alco	Alco	Alco-Schenectady
Year	1911	1912	1919
Valve Gear	Walschaert	Walschaert	Baker
	Locomotive Length and Weight
Driver Wheelbase	13'	10'	10.50'
Engine Wheelbase	48.83'	48.83'	45.75'
Ratio of driving wheelbase to overall engine wheebase	0.27	0.20	0.23
Overall Wheelbase (engine & tender)	87.48'	80.50'	89.42'
Axle Loading (Maximum Weight per Axle)		62300 lbs	60100 lbs
Weight on Drivers	337500 lbs	364900 lbs	358000 lbs
Engine Weight	400000 lbs	434400 lbs	448000 lbs
Tender Light Weight		168500 lbs	206500 lbs
Total Engine and Tender Weight	400000 lbs	602900 lbs	654500 lbs
Tender Water Capacity	9000 gals	9000 gals	12000 gals
Tender Fuel Capacity (oil/coal)	15 tons	15 tons	16 tons
Minimum weight per yard of rail on which locomotive could run	93.75 lb rail	101.36 lb rail	99.44 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	56"	56"	57"
Boiler Pressure	200 psi	210 psi	225 psi
Cylinders (dia x stroke)	22" x 32"	22" x 32"	23" x 32"
Low Pressure Cylinders (dia x stroke)	35" x 32"	35" x 32"	35" x 32"
Tractive Effort	67403 lbs	70773 lbs	79336 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	5.01	5.16	4.51
	Heating Ability
Firebox Area	344 sq. ft	370 sq. ft	416 sq. ft
Grate Area	72.20 sq. ft	72.50 sq. ft	76.30 sq. ft
Evaporative Heating Surface	5042	4902	5443
Superheating Surface	911	975	1292
Combined Heating Surface	5953	5877	6735
Evaporative Heating Surface/Cylinder Volume	358.12	348.18	353.72
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	14440	15225	17167.50
Same as above plus superheater percentage	16649.78	17750.84	20460.81
Same as above but substitute firebox area for grate area	79328.61	90590.51	111555.63
Power L1	7837.28	8540.46	11487.76
Power MT	307.17	309.59	424.46