Lake Shore & Michigan Southern / Toledo & Ohio Central 2-6-2 "Prairie" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class J-40D (Locobase 5213)

Virtually identical to the J-40g that preceded them by a year, these 5 were also superheated, but fitted with Baker rather than Walschaerts gear. Like the J-40gs, these had 11"-diameter piston valves with a relatively short 5 1/2" travel and the firebox heating surface included 24.56 sq ft of arch tubes. The 1917 diagrams clearly show an increase in superheater area even though both classes had the same number and diameter of superheater flues.

Data from (visited December 2002).

Class J-40G (Locobase 5212)

A large, high-speed Prairie that certainly entered service with a saturated-steam boiler; a twin to the Lake Shore & Michigan Southern's J-40 of a year earlier. The firebox heating surface included 24.56 sq ft of arch tubes.

The T&OC's quartet were superheated before 1917 when the New York Central's reference diagram was prepared.

By that time, the locomotive had sizable 11"-diameter piston valves with a relatively short 5 1/2" travel.

Data from (visited December 2002).

Class J/J-40a, b (Locobase 816)

Data from "New Passenger Locomotives for the Lake Shore & Michigan Southern", Railroad Gazette, Volume 33, No 13 (29 March 1901), pp. 220-221 Works numbers were 3733-3734 in January 1901 and 3866-3874 in June.

Lake Shore & Michigan Southern was a New York Central subsidiary.

Steam admission through 11" (279 mm) piston valves.

Drury (1993) notes that this class carried too much weight on their drivers. Railroad Gazette commented that compared to the ten-wheelers delivered in 1899, these engines showed more heating surface, but added that "the increase results from the use of 19-ft tubes, forming heating surface of doubtful value." RG also observed the smaller firebox heating surface, implicitly criticizing the design by adding that 1 sq ft of firebox heating surface is worth 10 in the tubes. In this case, the writer added, that may be too small a ratio. The wide grates made for easier firing, however, and a review later in the year said they had shown "economy in fuel and remarkable ability to haul heavy trains at high speed."

Perhaps stung by the adverse comments, F J Cole, Alco's well-known and respected Assistant Mechanical Engineer, presented the class as part of his parade of recent locomotives in a paper delivered to the New York Railroad Club on 21 November 1901. Noting the ample 11", central-admission piston valves that fed the cylinders, he also took on both the weight and tube-length issues. "These engines have been very carefully designed to secure a maximum boiler capacity with ample strength of running gear. Cast steel and pressed steel have been largely used and great care taken to eliminate unnecessary weight."

One can read the laurel offered to W H Marshall, LS & MS's Superintendent of Motive Power, a couple of ways. He was "...much to be commended in having the courage of his convictions regarding this design." In other words, he's the one who asked for long tubes. "The successful performance of these engines proves that no special difficulty has thus far been encountered in their use."

Staufer (1967), p 216, notes that their success wasn't particularly due to the Prairie wheel arrangement, but instead to the large boiler. On the other hand, he says, the design's tendency to "nose" at high speed was due to how the drivers and pony trucks were equalized and the weight distribution (alluded to in the above-quoted RG article) and a short main rod. When later modified with Walschaerts gear, they acquired the nickname "Grasshoppers".

Some transferred to the Toledo & Ohio Central; most retired early.

Class J/J-40c, d (Locobase 16148)

Data from "New Passenger Locomotives for the Lake Shore & Michigan Southern", Railroad Gazette, Volume 33, No 13 (29 March 1901), pp. 220-221 Works numbers were 26435-26446 in November 1902; 28803-28857-28872-28876, 29272-29276 in September 1903; 29419 in March 1904

Locobase supposes that the LS&MS did in fact find its 1901 Prairies (Locobase 816) lacking in heat production, as the Railroad Gazette had suggested at the time. But rather than shortening each 2 1/4" tube by some amount, as the RG might have recommended, the railroad and Brooks instead decreased tube diameters to 2" and inserted 59 more in the same boiler. Tube heating surface area increased by 237 sq ft (22.02 sq m) or 7 1/2%. Firebox heating surface increased by 16 sq ft (1.49 sq m) with the addition of firebrick tubes. Driver diameter grew by an inch.

Otherwise, the design remained unchanged. Piston valves still measured 11" (279 mm) in diameter.

Class K/J-41 (Locobase 5348)

Data from "Powerful Prairie Type Passenger Locomotive," American Engineer and Railroad Journal, Volume 78, No 11 (November 1904), pp. 412-413; No 12 (December 1904), p. 479 ; and Volume 79, No 1 (January 1905), pp.21-22. See also "New Prairie Type Locomotive Lake Shore & Michigan Southern Railway," Railway Master Mechanic, Vol XXX, No 6 (June 1906), pp. 193-194.

Lake Shore & Michigan Southern was a New York Central subsidiary. The RMM editor offered this detail about these large express engines: "Two special points are noted, which are different from their previous engines of this class, namely : The Walschaert valve gear and the trailing truck with outside bearings."

An article earlier in the RRM issue noted that one big advantage of Walschaert gear is that its linkages overcame the problem of the engineer having to move increasing weight when he shifted the reverse lever. The LS & MS was reported to have had great success with the mechanism.

The AERJ said that this "magnificent passenger locomotive ...[was] built to do work which now requires the Class J engines [Locobases 816 and 16147] to 'double head'". The journal spotlighted the Buffalo-Cleveland Lake Shore Express, a 13-car train with a trailing load of 743 tons that took 4 hours and 10 minutes to cover the 183 miles, thus averaging 44 mph.

To achieve this performance, the builder increased cylinder diameter by an inch, reduced driving diameter by two inches, increased piston valve diameter by an inch to 12" (305 mm), reverted to the 2 1/4" tube diameter of the first J class, but increased the count by 37 tubes, enlarged the grate area by 7 1/2 sq ft (0.7 sq m) even as it reduced the firebox's width by a foot. This last change pleased the firemen on the locomotives, AERJ claimed. They preferred a firebox 6 ft wide and 9 ft long to 7 ft wide and 7 ft long.

Drury (1993) says that in contrast to the earlier J-40s, these Prairies were successful enough to be rebuilt as K-41 Pacifics in 1924-1925. Staufer (1967) says the improvement came in part from lengthening the engine by 5 feet.

Specifications by Steve Llanso of Sweat House Media
ClassJ-40DJ-40GJ/J-40a, bJ/J-40c, dK/J-41
Locobase ID5213 5212 816 16148 5348
RailroadToledo & Ohio Central (NYC)Toledo & Ohio Central (NYC)Lake Shore & Michigan Southern (NYC)Lake Shore & Michigan Southern (NYC)Lake Shore & Michigan Southern (NYC)
Number in Class54133335
Road Numbers9572-95769568-9571650-662/4650-4662663-695/4663-46953700-3714/4700-4734
Number Built54133335
Valve GearBakerWalschaertStephensonStephensonWalschaert
Locomotive Length and Weight
Driver Wheelbase14'14'14'14'14'
Engine Wheelbase31.83'31.83'31.83'31.83'34.25'
Ratio of driving wheelbase to overall engine wheebase 0.44 0.44 0.44 0.44 0.41
Overall Wheelbase (engine & tender)60.21'60.21'57.33'57.33'62.28'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers134000 lbs134000 lbs130000 lbs124000 lbs165200 lbs
Engine Weight186000 lbs186000 lbs174500 lbs186000 lbs233000 lbs
Tender Light Weight138500 lbs138500 lbs148500 lbs126600 lbs159900 lbs
Total Engine and Tender Weight324500 lbs324500 lbs323000 lbs312600 lbs392900 lbs
Tender Water Capacity7000 gals7000 gals7000 gals7000 gals8000 gals
Tender Fuel Capacity (oil/coal)13 tons13 tons13 tons13 tons15 tons
Minimum weight of rail (calculated)74 lb/yard74 lb/yard72 lb/yard69 lb/yard92 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter81"81"80"81"79"
Boiler Pressure180 psi180 psi200 psi200 psi200 psi
Cylinders (dia x stroke)20.5" x 28"20.5" x 28"20.5" x 28"20.5" x 28"21.5" x 28"
Tractive Effort22227 lbs22227 lbs25005 lbs24696 lbs27852 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 6.03 6.03 5.20 5.02 5.93
Heating Ability
Firebox Area190 sq. ft190 sq. ft174 sq. ft190 sq. ft227 sq. ft
Grate Area48.60 sq. ft48.60 sq. ft48.50 sq. ft48.50 sq. ft55 sq. ft
Evaporative Heating Surface2821 sq. ft2822 sq. ft3343 sq. ft3596 sq. ft3905 sq. ft
Superheating Surface855 sq. ft570 sq. ft
Combined Heating Surface3676 sq. ft3392 sq. ft3343 sq. ft3596 sq. ft3905 sq. ft
Evaporative Heating Surface/Cylinder Volume263.73263.82312.53336.18331.90
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation874887489700970011000
Same as above plus superheater percentage10760102359700970011000
Same as above but substitute firebox area for grate area4206640014348003800045400
Power L12604820223105031147511280
Power MT1285.66998.15534.35612.05451.60


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