
Built in two batches: 1600-1644 in 1940-1944, 1645-1659 in 1948. Firebox had 3 syphons and arch tubes combining for 162 sq ft of heating surface as well as a huge combustion chamber. Eight similar engines with smaller boilers and superheaters went to the Virginian. Could operate 11,500-ton coal trains at speeds up to 45 mph. Probably the heaviest 12-axle locomotives ever built, with certainly the highest axle load ever put on rails. Average axle load was 84,650 lb and the first driving axle bore 86,700 lb.
Puzzle: C&O Power gives higher weight on drivers (507,900 lb for the first batch, 504,010 lb for the 1948 engines), and heavier engine weights (771,300 lb and 751,830 lb, respectively. Possible answer: Cyclopedia weights were as designed, C&O Power weights may have come from C&O drawings.
Bob Quehl (EMail:rquehl@adelphia.net) from Pittsburgh, PA offered considerable detail on the difference as well as other information ( http://www.worldrailfans.org/Forum/1998/Jan/2281650.shtmlon Feb 4 2000, 4:06) " In the December 1998 issue of Trains Magazine there is a very interesting article that suggests the first 10 H-8s delivered in December 1941 to January 1942 weighed actually weighed in the area of 775,330 lbs in "working order". This was just the engine weight including water in the boiler, 12,000 lbs of sand in the domes an a two man engine crew. This is interesting because the specifications for the order between the C&O and LIMA called for a weight of 726,000 lbs.
"Apparently it became known by some senior managers at the C&O that the engines were considerably overweight. They did not start to raise questions as there was a cover-up attempt by C&O and Lima, until the neighboring Virginian Rail Road ordered their own Alleghenies. The president of the Virginian, one Frank Beale, was a former high level person in the C&O and knew what the H-8 was supposed to weigh. When he got the specifications from Lima for the Virginian's engines, he could not understand why they weighed considerably more and one thing led to another. The Virginian had a lot of trouble getting their 8 Alleghenies delivered as the surrounding rail roads did not want that much weight on their rails ...One engineer at Lima gave the H-8's weight as high as 778,200 lbs. For the engine and tender combined weight I have seen several references in other sources around 1,200,000 lbs.
As for power, in 1943 a C&O dynamometer test reportedly gave the highest drawbar horsepower (where it really counts) of any locomotive made. They had the highest weight on drivers of any steam locomotive, and must have really pounded the rails. With 67 or 69 inch drivers (I can't remember which off hand) they would easily have been capable of 60 mile an hour or faster speeds and I have seen some photos of them hauling express box cars trains. I have also read that some of them were used during WW II to haul fast troop trains for the military."
| Specifications | |
|---|---|
| Class | H-8 |
| Locobase ID | 304 |
| Railroad | Chesapeake & Ohio (C & O) |
| Whyte | 2-6-6-6 |
| Road Numbers | 1600-1659 |
| Gauge | Std |
| Builder | Lima |
| Year | 1940 |
| Valve Gear | Baker |
| Locomotive Length and Weight | |
| Driver Wheelbase | 11.83' |
| Engine Wheelbase | 62.50' |
| Ratio of driving wheelbase to overall engine wheebase | 0.19 |
| Overall Wheelbase (engine & tender) | 112.92' |
| Axle Loading (Maximum Weight per Axle) | 86700 lbs |
| Weight on Drivers | 471000 lbs |
| Engine Weight | 724500 lbs |
| Tender Light Weight | 341600 lbs |
| Total Engine and Tender Weight | 1066100 lbs |
| Tender Water Capacity | 25000 gals |
| Tender Fuel Capacity (oil/coal) | 25 tons |
| Minimum weight per yard of rail on which locomotive could run | 130.83 lb rail |
| Geometry Relating to Tractive Effort | |
| Driver Diameter | 67" |
| Boiler Pressure | 260 psi |
| Cylinders (dia x stroke) | 22.5" x 33" (4) |
| Tractive Effort | 110211 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.27 |
| Heating Ability | |
| Firebox Area | 762 sq. ft |
| Grate Area | 135.20 sq. ft |
| Evaporative Heating Surface | 7240 |
| Superheating Surface | 3186 |
| Combined Heating Surface | 10426 |
| Evaporative Heating Surface/Cylinder Volume | 238.37 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 35152 |
| Same as above plus superheater percentage | 45893.83 |
| Same as above but substitute firebox area for grate area | 258661.95 |
| Power L1 | 37972.11 |
| Power MT | 1066.42 |
The Virginian 2-6-6-6s came it at about 754,000 lbs, still overweight, but less so than the C&O engines. The final 15 C&O engines came in at 757,830 lbs. Lima ended up paying the C&O a penalty, perhaps as much as $3,000,000 because of this overweight problem.
No matter the actual locomotive weight, this weight makes the Allegheny the
heaviest of any reciprocating steam locomotive built in North America, even
heavier than the Big Boy.
Photos
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