Chesapeake & Ohio 2-6-6-6 "Allegheny" Locomotives in the USA (2024)

In the 1930s, the C&O improved its railroad by boring new tunnels andenlarging others. The Class T-1 "Texas" type 2-10-4s also arrived in theearly 1930s and seemed to be the choice for hauling its coal trains overthe 80 miles of track from Hinton, WV east to Clifton Forge, VA. This runincluded a 13 mile .577% grade to the 2,072 foot summit of an Alleghenymountain and then a descent down a 1.14% grade to Clifton Forge. Its2-6-6-2s were getting old and the 2-8-8-2s, delivered in the 1920s, (whichused simple expansion because of tight tunnel clearances) were not up tothe task. On the brink of ordering more 2-10-4s the C&O was approached bythe Lima Locomotive Company with a new and more powerful locomotive design.

This design was a six-coupled, single-expansion articulated with 67" diameterdrivers for speed, a 9' x 15' firebox with a very large boiler for steamingand 778,000 pounds of locomotive weight to assure tractive effort. The largefire box was placed behind the drivers and required a six-wheel trailingtruck to support it. This gave the design a wheel arrangement of 2-6-6-6.With four 22.5" diameter x 33" stroke cylinders, a 260 psi boiler pressureand the 67" diameter drivers it could exert 110,200 pounds of tractiveeffort.

The C&O agreed and placed an order for ten of these 2-6-6-6 locomotives andLima delivered them in December, 1941. They were designated Class H-8 andassigned road numbers 1600 through 1609. With a new wheel arrangement camea new name. The C&O selected the name "Allegheny" for the mountain rangethat this new locomotive would do its work. An article by King in "Trains"in the early 2000s stated that the C&O Alleghenies cost around $230,000each.

The tenders for these new locomotives were of the largest type used on theC&O, with a 25,000 gallon water tank and a 25 ton coal bunker. In order tokeep the overall length of the locomotive and tender within the limit thatexisting turntables could handle it was necessary to make the rear section ofthe tender higher, thus causing more weight to be at the rear than the front.The tender had a six-wheel leading truck, but an eight-wheel trailing truckwas needed to carry the weight in the rear.

In operation, one "Allegheny" leading and one pushing could move a 140 carloaded coal train up the mountain from the Hinton terminal. At the top thepusher would be taken off, turned around and sent back to the Hintonterminal. The single leading "Allegheny" could handle the decent down themountain to Clifton Forge where it would be turned around for a return tripwith a train of empty coal cars.

The C&O had 23 of its "Alleghenies" equipped with steam heat and signallines for passenger service, but they were used sparingly, pullingan occasional heavy mail train or a troop train during World War II.The "Allegheny" may have been the ultimate freight locomotive. They wereable to achieve a very impressive record even though they were used in amanner that didn't fit perfectly with their design. The Allegheny boilerswere capable of delivering up to 8000 HP! This was far greater than anyother reciprocating steam locomotive could develop. However, the C&Oused the H-8s in "coal drag" service where they were unable to realizetheir full potential as high speed locomotives. The C&O Alleghenieswere designed to haul 5,000 tons at 45mph, but unfortunately were usedto haul trains of 10,000 or more tons at 15mph. C&O's 2-6-6-6s werevery impressive locomotives. However, they were never used to their fullpotential. The "Allegheny" was truly magnificent in its role, but asgood as it was it could not win the battle with the diesel. The C&O's"Alleghenies" were taken out of service beginning in 1952 with the lastfire dropped in 1956.

It should also be noted that the Alleghenies were some of the most powerfulsteam locomotives ever built. At 40 MPH they could generate 7,500 HP.This power was only exceeded by the PRR Q-2 Class (7,987HP). By contrastthe UP Big Boy could generate a maximum of 6,200 drawbar HP.

Fortunately, two of the C&O "Allegheny" type locomotives survive today,number 1601 at the Henry Ford Museum in Dearborn, MI and number 1604 at theB&O Railroad Museum in Baltimore, MD.

Numbers 1600, 1602, 1603 and 1605-1659 were scrapped between 1952 and 1956.

The Controversy Around the Weight of These Locomotives

There has been substantial controversy about discrepancies on the actualweight of the Alleghenies. Various sources will list different engineweights and weight on drivers for the H-8s. The discrepancies were in partdue to the design weight as specified by the C&O and then subsequent designchanges submitted by the C&O. For example, while the locomotives were beingbuilt, the C&O suggested four different design changes of the connectingrods. Each of the changes resulted in increased locomotive weight.

I've tried to make sense of the various weights that have been reported forthese locomotives (the first batch). I don't know if we'll ever know thetrue weight. What I can say is that it was roughly equal to that of theUP Big Boys. See the table below that shows where some of the reportedweights and their source.

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