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


Class Details by Steve Llanso of Sweat House Media

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" (279 mm)-diameter piston valves with a relatively short 5 1/2" travel.

Data from [] (visited December 2002).


Class J-40h (Locobase 5213)

Data from [] (visited December 2002) and T&OC-Z&W - 6 1920 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection.

Virtually identical to the J-40g that preceded them by a year, these five were also superheated, but fitted with Baker rather than Walschaerts gear. Like the J-40gs, these had 11" (279 mm)-diameter piston valves with a relatively short 5 1/2" (140 mm) travel and the firebox heating surface included 24.56 sq ft (2.28 sq m) 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.


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 See also NYC&HR 8-1917 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection; Alvin Staufer, New York Central's Early Power. Volume II 1831 - 1916 (Alvin F. Staufer, 1967), p 216; and George Drury, Guide to North American Steam Locomotives (Waukegan, WI: Kalmbach Publshing, 1993--rev ed 2015), p. 236. (Thanks to Chris Hohl for his 9 February 2023 email noting the original tender capacities.) Works numbers were 3733-3734 in January 1901 and 3866-3874 in June.

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

Chris Hohl reported that the original specs for the tender included 6,000 US gallons (22,710 lites) of water and 11 tons (10 metric tons) of coal; loaded, it weighed 118,000 lb (53,524 kg). By 1917, larger tenders carried the amounts shown in Locobase's specs.

Drury (1993) wrote 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" (279 mm), 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." No one seems to have noticed that the tubes' length-to-diameter ratio was a nearly ideal (at least theoretically) 101:1.

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. By the time five of the class had been sold to the Toledo & Ohio Central, they had been superheated; see Locobase 5213.


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; see Locobases 5579-5580. Staufer (1967) says the improvement came in part from lengthening the engine by 5 feet.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassJ-40gJ-40hJ/J-40a, bJ/J-40c, dK/J-41
Locobase ID5212 5213 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)
CountryUSAUSAUSAUSAUSA
Whyte2-6-22-6-22-6-22-6-22-6-2
Number in Class45133335
Road Numbers9568-95719572-9576/9584-9588650-662/4650-4662663-695/3663-3695/4663-46953700-3714, 4715-4734
GaugeStdStdStdStdStd
Number Built133335
BuilderLS&MSLS&MSBrooksAlco-BrooksAlco-Brooks
Year19091917190119021904
Valve GearWalschaertBakerStephensonStephensonWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)14 / 4.2714 / 4.2714 / 4.2714 / 4.2714 / 4.27
Engine Wheelbase (ft / m)31.83 / 9.7031.83 / 9.7031.83 / 9.7031.83 / 9.7034.25 / 10.44
Ratio of driving wheelbase to overall engine wheelbase 0.44 0.44 0.44 0.44 0.41
Overall Wheelbase (engine & tender) (ft / m)60.21 / 18.3560.21 / 18.3557.33 / 17.4757.33 / 17.4762.28 / 18.98
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)134,000 / 60,781134,000 / 60,781130,000 / 58,967124,000 / 56,246165,200 / 74,934
Engine Weight (lbs / kg)186,000 / 84,368186,000 / 84,368174,500 / 79,152186,000 / 84,368233,000 / 105,687
Tender Loaded Weight (lbs / kg)138,500 / 62,823138,500 / 62,823148,500 / 67,359126,600 / 57,425159,900 / 72,530
Total Engine and Tender Weight (lbs / kg)324,500 / 147,191324,500 / 147,191323,000 / 146,511312,600 / 141,793392,900 / 178,217
Tender Water Capacity (gals / ML)7000 / 26.527000 / 26.527000 / 26.527000 / 26.528000 / 30.30
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)13 / 1213 / 1213 / 1213 / 1215 / 14
Minimum weight of rail (calculated) (lb/yd / kg/m)74 / 3774 / 3772 / 3669 / 34.5092 / 46
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)81 / 205781 / 205780 / 203281 / 205779 / 2007
Boiler Pressure (psi / kPa)180 / 12.40180 / 12.40200 / 13.80200 / 13.80200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)20.5" x 28" / 521x71120.5" x 28" / 521x71120.5" x 28" / 521x71120.5" x 28" / 521x71121.5" x 28" / 559x711
Tractive Effort (lbs / kg)22,227 / 10082.0122,227 / 10082.0125,005 / 11342.0924,696 / 11201.9327,852 / 12633.47
Factor of Adhesion (Weight on Drivers/Tractive Effort) 6.03 6.03 5.20 5.02 5.93
Heating Ability
Tubes (number - dia) (in / mm)196 - 2" / 51196 - 2" / 51285 - 2.25" / 57344 - 2" / 51322 - 2.25" / 57
Flues (number - dia) (in / mm)26 - 5.375" / 13726 - 5.375" / 137
Flue/Tube length (ft / m)19 / 5.7919 / 5.7919 / 5.7919 / 5.7919.50 / 5.94
Firebox Area (sq ft / m2)190 / 17.66190 / 17.66174 / 16.16190 / 17.65227 / 20.63
Grate Area (sq ft / m2)48.60 / 4.5248.60 / 4.5248.50 / 4.5148.50 / 4.5155 / 5.11
Evaporative Heating Surface (sq ft / m2)2822 / 262.272821 / 262.173343 / 310.573596 / 334.083905 / 362.55
Superheating Surface (sq ft / m2)570 / 52.97855 / 79.46
Combined Heating Surface (sq ft / m2)3392 / 315.243676 / 341.633343 / 310.573596 / 334.083905 / 362.55
Evaporative Heating Surface/Cylinder Volume263.74263.64312.43336.07331.78
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation874887489700970011,000
Same as above plus superheater percentage10,23510,7609700970011,000
Same as above but substitute firebox area for grate area40,01442,06634,80038,00045,400
Power L120,21726,04010,50011,47111,276
Power MT997.851285.26534.20611.84451.44

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