C&O’s M-1 Steam Turbine Locomotives: Specs, Roster, History

Last revised: October 5, 2026

The Chesapeake & Ohio’s Class M-1 was three steam-turbine-electric locomotives, 500–502, built by the Baldwin Locomotive Works with Westinghouse electrical equipment in 1947 and 1948. They were ordered for The Chessie, a daylight streamliner between Washington and Cincinnati that never entered revenue service. A coal-fired firetube boiler supplied a Westinghouse turbine rated at 6,000 horsepower. The turbine turned four generators, and the generators fed eight traction motors. The axle arrangement is 2-C1+2-C1-B.

Number 500 was the 1947 engine. Numbers 501 and 502 followed early in 1948. The class was out of service in 1949 and scrapped in 1950. None was saved. The company is the Chesapeake & Ohio, and the steam roster is the C&O steam locomotives page. The train they were built for is The Chessie. The other American steam-turbine experiments are the Union Pacific–General Electric pair of 1938, the Pennsylvania Railroad’s S2 on the Pennsylvania steam roster, and the Norfolk & Western’s Jawn Henry.

Chesapeake and Ohio Class M-1 steam turbine 500, yellow nose and gray flanks, in May 1948

Chesapeake & Ohio M-1 No. 500 in May 1948. The nose and the belt are yellow, the flanks gray, and a blue stripe runs along the bottom. The Chessie cat is on the nose, the road name is in script on the belt, and 500 is in the number boards. A blue-striped car is coupled behind. Baldwin–Westinghouse, 1947. Photographer unknown.

On this page: At a glance · An order placed in 1944 · The machine · Coal in the nose · Forty-six Budd cars · On the road · Roster

At a glance

Item	Detail
Railroad	Chesapeake & Ohio. Letter classes. This one is M-1
Type	Coal-fired steam-turbine-electric. Firetube boiler, Westinghouse turbine, four generators, eight traction motors
Quantity	Three. Numbers 500, 501, and 502
Builder	Baldwin, Eddystone, mechanical. Westinghouse, electrical. Works 73079–73081
Built	500 in 1947. 501 and 502 early in 1948
Arrangement	2-C1+2-C1-B. Eight motored axles. Baldwin’s construction list entered the same engines as 4-8-0-4-8-4 TE
Drivers	40 in
Boiler	Firetube, 310 psi, superheated. Exhaust to atmosphere
Power	Turbine 6,000 hp. Generators 4,960 hp combined. Design speed 100 mph
Weight and length	Engine 856,000 lb (428 tons), 106 ft. Water tender 48 ft, 25,000 gallons. Over the couplers, 154 ft ¾ in
Coal	29.25 tons, in a bunker ahead of the cab
Retired	Out of service in 1949. Scrapped in 1950. All three

Engine length, tender length, the 428-ton engine weight, and the 6,000-horsepower turbine are Geoffrey H. George’s account in Trains for July 1968. Driver diameter, boiler pressure, coal, water, the 154-foot coupler length, and the 4,960-horsepower generator figure are the published class specification, including Arthur R. Railton’s Popular Mechanics article of March 1948 and J. Parker Lamb’s class table. Information compiled October 5, 2026.

An order placed in 1944

Robert R. Young took the chair of the Chesapeake & Ohio in 1942, and he wanted a new daylight train from Washington to Cincinnati as soon as the war was over. The railroad’s freight business was coal. Its mechanical men were also on record, in the March 1948 Popular Mechanics account, that the oil supply they could see might be gone in 25 or 30 years. A coal-burning passenger locomotive was the brief they gave the builders.

In 1944 a group of coal producers and railroads had started a longer research program on a coal-fired turbine. Alongside that program, the railroad’s own research office, under the aeronautical engineer K. A. Browne, went to Baldwin and Westinghouse for a locomotive that could be built from parts already in production: a firetube boiler, a steam turbine, and an electric transmission. Three were ordered late in 1944. Baldwin’s construction numbers for the three are 73079–73081. The list called the wheel arrangement 4-8-0-4-8-4 TE. The axles, counted the way the motors were applied, are the 2-C1+2-C1-B below.

The price of the three locomotives was $1.6 million, research and development aside. Number 500 was finished in 1947. On Saturday, December 13, 1947, it stood for a day in the Columbus freight yards at Dennison and Dublin Avenues, and the Columbus Dispatch of the next morning said 501 and 502 were still on the floor at Baldwin. They came early in 1948. The railroad called the class the largest single-unit passenger locomotives in the world.

The machine

The turbine was a Westinghouse machine rated at 6,000 horsepower. It drove four direct-current generators, mounted in pairs, each of 1,000 kilowatts. Together the generators were rated at 4,960 horsepower, and they fed eight axle-hung traction motors. Uberto Bajocchi’s 1949 technical account of the same locomotive puts the turbine’s top speed at 6,000 revolutions per minute, with a 6-to-1 reduction gear between the turbine and the generators, and treats 2,400 revolutions as the floor for ordinary running. Exhaust steam went to the atmosphere. The boiler was a conventional firetube boiler pressed to 310 pounds, and the steam was superheated.

The throttle had eleven positions. Railton rode a trial and wrote that 70 miles an hour was notch 7. The engineer, held to a local limit of 75, told him he would like to pull the handle back to eleven. The design speed was 100 miles an hour. Railton’s figures for the train the engines were meant to run are 666 miles, Washington to Cincinnati, in 11 hours 45 minutes, and the designers’ prediction was a round trip over that route with no servicing stop.

Specification	Class M-1, 500–502
Type	Steam-turbine-electric. Coal fired. Non-condensing
Builder	Baldwin Locomotive Works, works 73079–73081. Westinghouse electrical equipment
Arrangement	2-C1+2-C1-B. Eight motored axles, six idle axles on the locomotive, six axles under the water tender
Driver diameter	40 in
Boiler	Firetube, 310 psi, superheated
Turbine	Westinghouse, 6,000 hp
Generators	Four, 1,000 kW each, 4,960 hp combined
Traction motors	Eight
Design speed	100 mph. Railton’s cruise notch, 70 mph
Engine length	106 ft
Engine weight	856,000 lb (428 tons)
Coal	29.25 tons, in the nose bunker
Water tender	48 ft. 25,000 gallons. Two six-wheel trucks
Length over couplers	154 ft ¾ in

The forward frame carries a four-wheel idle truck, three motored axles, and one idle axle. The frame behind it carries a four-wheel idle truck, three motored axles, one idle axle, and a four-wheel truck with both axles motored. That is the B at the end of 2-C1+2-C1-B. Fourteen axles under the locomotive and six under the tender are twenty pairs of wheels, which is the count the Dispatch printed while 500 was in Columbus.

Coal in the nose

The crew sat ahead of the boiler. The coal bunker was in the nose, in front of the cab. The firebox was immediately behind the cab, and a stoker carried coal from the bunker through the cab to the fire. The boiler barrel ran rearward from that firebox. The turbine and the generators sat at the rear of the locomotive body, and the water tender coupled on behind them. The tender held 25,000 gallons and was styled to run with passenger cars. From the outside the shrouding covered the joints, which is why a side view reads as one long carbody with a yellow nose.

On 500, as photographed in May 1948, that nose and the belt are yellow, the flanks are gray, and a blue stripe runs along the bottom. The Chessie cat is on the nose. The Dispatch, looking at the same engine in December 1947, called the jacket orange, the apron aluminum, and the striping blue. The yellow in the photograph is the color that newspaper was describing.

Forty-six Budd cars

The cars were a Budd order, placed in 1944: 46 stainless-steel cars, baggage, coaches, domes, lounges, and diners, lettered for The Chessie. They arrived in August 1948. George’s figure for the bill is $6.1 million. The train they were meant to make up was an all-coach daylight run, Washington to Cincinnati, with the M-1 as its road power. The conventional engines rebuilt for the same service were five Class L-1 Hudsons, 490–494, rebuilt from F-19 Pacifics in 1947. Number 490 is the one that survives, at the B&O Railroad Museum.

The railroad ran a test train. The fall 1948 folder still showed the George Washington, the Sportsman, and the F.F.V. The 1948 annual report passed over the new equipment. By October 1948 the consists had been broken up. Most of the cars went to the Pere Marquette streamliners between Chicago and Grand Rapids. The train itself is The Chessie page. Passenger traffic was already falling, and the Chesapeake & Ohio Historical Society’s account of the cancellation adds a coal strike against the railroad’s revenue that year.

What the three turbines then did is on the steam roster as a closed experiment. The later coal-fired turbine, a different machine with a Babcock & Wilcox water-tube boiler, was the Norfolk & Western’s 2300 of 1954. The direct-drive turbine, with no electric transmission, was the Pennsylvania’s S2, engine 6200, a Baldwin 6-8-6 of 1944. Both of those stories sit with the steam-turbine locomotives overview.

Chesapeake and Ohio steam turbine electric M-1 500 during trials in 1947

Chesapeake & Ohio steam-turbine #500 (Class M-1) during trials near Covington, Virginia in late 1947. Three of these Baldwin–Westinghouse machines, 500–502, were meant to power the streamliner The Chessie, which was never launched. They were scrapped in 1950.

On the road

While the cars were still expected, the railroad showed the locomotives off. Number 500 and one of the new Chessie diners went to the Chicago Railroad Fair in 1948 and again in 1949. In service the assignments were ordinary passenger trains, and they were short. William J. Sparkmon’s account gives one of them in detail. Train 47, the Norfolk section of the Sportsman, carried a turbine from Clifton Forge to Hinton, West Virginia, and the engine came off at Hinton because the westbound track there had no coaling station. Another trip, a photo train from Clifton Forge to Charlottesville over the Mountain Subdivision, came home with cracked wheels. That engine was in the shop for two weeks.

The same territory, Clifton Forge to Charlottesville, is where James E. Casto places the class once The Chessie was gone. The mechanical record is the one Thomas W. Dixon, Jr. and the later technical summaries agree on. Coal dust worked into the forward traction motors. Water leaks from the boiler and the piping shorted motors farther back. The turbine, built up from stationary and marine practice, shook hard enough to be felt in the train. The railroad never got 500, 501, or 502 through from Washington to Cincinnati. The cost of keeping them running sat above the cost of a modern reciprocating engine, and above a diesel.

All three were out of use in 1949. All three were scrapped in 1950.

Roster

No.	Builder	Built	Disposition	Notes
500	Baldwin–Westinghouse	1947	Scrapped 1950	First of the class. On display at Columbus, December 13, 1947. Chicago Railroad Fair, 1948 and 1949. The engine in the photograph
501	Baldwin–Westinghouse	Early 1948	Scrapped 1950	Still under construction when 500 was shown at Columbus
502	Baldwin–Westinghouse	Early 1948	Scrapped 1950	Still under construction in December 1947

Baldwin’s three construction numbers are 73079–73081. The class is the whole of the C&O steam-turbine roster. Nothing of the three survives.

Where they were seen

When	What the record shows
Late 1944	Three locomotives ordered from Baldwin and Westinghouse
1947	No. 500 delivered. Trials based at Clifton Forge
December 13, 1947	No. 500 on display at Columbus. Nos. 501 and 502 still at Baldwin
Early 1948	Nos. 501 and 502 delivered
1948 and 1949	No. 500 and a Chessie diner at the Chicago Railroad Fair
August 1948	Forty-six Budd cars for The Chessie on the property
October 1948	Chessie consists broken up. Cars reassigned, most of them to the Pere Marquette trains
In service, 1948–49	Train 47, Clifton Forge to Hinton, cut off for lack of a westbound coaling station. A Mountain Subdivision photo train, Clifton Forge to Charlottesville, returned with cracked wheels
1949	All three out of use
1950	All three scrapped

Sources

George, Geoffrey H. “This Was The Train That Was (But Never Was).” Trains, Vol. 28, No. 9 (July 1968). The order of late 1944, K. A. Browne’s office with Baldwin and Westinghouse, the firetube boiler and electric drive, the 106-foot engine and 48-foot water tender, the 428-ton engine weight, the 6,000-horsepower turbine, eight motors on a 2-C1+2-C1-B, coal in the nose and the turbine at the rear, $1.6 million for the three locomotives excluding research, and $6.1 million for the 46 Budd cars that arrived in August 1948. The 1948 annual report’s silence, and the fall 1948 timetable with no Chessie.
Railton, Arthur R. “Chessie Has That New Look.” Popular Mechanics (March 1948), pp. 107–111 and 252. The oil-supply concern, the eleven-notch throttle, 70 miles an hour on notch 7, the 75-mile trial, the designers’ 666-mile Washington–Cincinnati schedule in 11 hours 45 minutes, and the prediction of a round trip with no servicing stop. Baldwin’s construction entry of the class as 4-8-0-4-8-4 TE, works 73079–73081.
Lamb, J. Parker. Perfecting the American Steam Locomotive. Bloomington: Indiana University Press, 2003. P. 161. Locomotive weight, and the class specification that carries 40-inch drivers, 310 psi, 29.25 tons of coal, 25,000 gallons, a 154-foot ¾-inch length over couplers, and eight traction motors. The generator rating of 4,960 horsepower is the figure paired with that specification and with Railton, p. 109.
Columbus Dispatch, December 14, 1947. No. 500 on display the previous day at Dennison and Dublin Avenues. Boiler behind the cab, coal bunker in front of the cab, 25,000-gallon water tender, 20 pairs of wheels, geared for 100 miles an hour. Nos. 501 and 502 still under construction. The jacket described as orange, with an aluminum apron and blue striping.
Bajocchi, Uberto. Technical account of the M-1, 1949, as reported in the later engineering summary of the class. Turbine speed of 6,000 revolutions per minute, a 6-to-1 reduction, and 2,400 revolutions as the floor in ordinary service. A stoker from the nose bunker through the cab to a firebox behind the crew.
Sparkmon, William J. “Previewing a Future That Never Was.” Classic Trains (March 16, 2012). No. 500 and a Chessie diner at the Chicago Railroad Fair in 1948 and 1949. Train 47, the Norfolk section of the Sportsman, Clifton Forge to Hinton, cut off where the westbound track had no coaling station. The Mountain Subdivision photo train and the cracked wheels. The decision that the turbines cost more to run than a modern steam locomotive, and more than a diesel, and the scrapping.
Dixon, Thomas W., Jr. Chesapeake & Ohio Railway: A Concise History and Fact Book. Clifton Forge, Va.: Chesapeake & Ohio Historical Society, 2012. The class as a coal-fired boiler driving traction motors, the Clifton Forge trials, and the service failures: coal dust in the motors, water on the electrical equipment, and vibration. The same failure modes, and the unbroken Washington–Cincinnati trip, are Douglas Self’s summary of the class.
Casto, James E. The Chesapeake and Ohio Railway. Charleston, S.C.: Arcadia, 2006. P. 62. The M-1s in service between Clifton Forge and Charlottesville, and the scrapping in 1950.
Wayner, Robert J., ed. Car Names, Numbers and Consists. New York: Wayner Publications, 1972. The 46-car Budd order. The Chesapeake & Ohio Historical Society’s account of the train adds the coal strike and the drop in passengers to the cancellation, and records that the cars were used on other trains. Reassignment of the consists by October 1948, most of them to the Pere Marquette Chicago–Grand Rapids streamliners, is the Chessie article on this site and the standard equipment account.
Solomon, Brian. American Steam Locomotive. Osceola, Wis.: Motorbooks International, 1998. P. 141. The 6,000-horsepower turbine rating and the end of the class in scrap. The Pennsylvania S2 and the Norfolk & Western 2300 are named here only as the other two machines. Their specifications stay on the Pennsylvania steam roster and on the Jawn Henry page.

Facebook X Pinterest Tumblr Reddit WhatsApp Messenger