Maine Central / Somerset / Washington County 4-6-0 "Ten-Wheeler" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 20 / G (Locobase 12815)

Data from DeGolyer, Volume 28, p 78. See also Walter Marshall MacDougall, The old Somerset railroad: a lifeline for northern Mainers (Camden, ME: Down East Books, 2000) and an extended description of the route at Locobase 11434. Works numbers were 26269-26270 in August 1905.

MacDougall places this pair of Ten-wheelers at the top of the scale for size and weight. They were bought, he says, to handle the grades above Bingham. Welcome as they were, the engines "...were ten feet longer than the biggest engines on the road. New additions had to be tacked onto the engine houses, and the turntables were extended." Pointing out that that was "no small job" and probably included constructing new pits of poured concrete. (p. 174).

But the two were quite a bit smaller than other standard-gauge Ten-wheelers, but served the Somerset for decades. After the Maine Central took over in 1911 (with 982 new rules for SRR hands to follow), the 20 and 21 were placed in class G and renumbered 106-107.

106 was scrapped in June 1930. MacDougall writes that Somerset Branch remained healthy into the 1930s, but MEC management were not inclined to maintain service. Thus passenger service north of Bingham ceased in 1932 past Bingham Heights and on 22 July 1933, the last train to Oakland ran. The 107 was scrapped by the MEC in May 1935.


Class 22/G (Locobase 11433)

Data from "Locomotive Building," The Railroad Gazette, Vol XLI, No 9 (31 August 1906), p. 56. See also DeGolyer, Vol 27, p. 78. Works numbers were 41436-41437.

See the description of the railway in Locobase 11434.


Class 4/G (Locobase 2983)

Data from 1899 Brooks catalogue. (Thanks to Bill Blakey for his 19 April 2017 email demonstrating that the locomotives mentioned here and those in Locobase 7308 (since deleted) were the same five engines.)

Builder info from B.Rumary, 25 Kingscombe, Gurney Slade, Radstock, BA3 4TH, ENGLAND and Jeremy Lambert as supplied by Allen Stanley in March 2004. Works #2943-2947, produced in April 1898.

See Locobase 2151 for a short history of this Maine shortline.

In the same month as the first three 4-4-0s (Locobase 2151) were produced for the WCRR, this quintet of Ten-wheelers also came to life. They apparently shared the same firebox and had the same number of fire tubes as the Americans, which they immediately preceded on Brooks' Dunkirk factory floor,. But each tube was 11" longer , the Ten-wheelers rolled on smaller drivers, and adhesion weight increased by more than 12 tons in each locomotive.

Unlike the 4-4-0s, however, three of these freight locomotives served Maine for almost 40 years and one fell just short of 50 years.

Road # Year Changed to new # MEC Scrapped

4 31 in Aug 1906 110 Nov 1918

5 32 in April 1906 112 Mar 1935

6 33 in Mar 1906 113 Feb 1935

7 34 in April 1905 114 June 1947

8 35 in April 1907 115 Aug 1935

In the 1920s, Baldwin and Alco's Schenectady Works each manufactured two new boilers. Baldwin order numbers 7480-1 and -2 were produced for 113-114 in 1921; Schenectady order numbers 89755-1 and -2 went into 112 and 115 in 1923

When Locobase first encountered this class in 2005-2006, he did not know the class's original owner (i.e., the WC), so he repeated the data.


Class N-275 (Locobase 7056)

Data from MEC 2 - 1923 and MEC & PTC 7- 1947 Maine Central locomotive diagrams supplied by Allen Stanley in May 2005 from his extensive Rail Data Exchange.

MEC passenger power expanded with the acquisition of these Ten-wheelers at the turn of the century. Schenectady delivered them in small batches in a sequence that coincided with the merger of several builders into the American Locomotive Company. The first 4 were Schenectady builder's numbers 4965-4966 & 5359-5360, the next 3 -- 1901 -- had numbers 6066-6068. Two years later, the last two were amalgamated builder's numbers 27660-27661.

All but 282 were superheated, according to the 1923 book, but none of the engines are credited with superheater in the 1947 edition. Possibly the superheaters had been removed.


Class N-283 (Locobase 7055)

Data from 1923 and 1924 Maine Central locomotive diagrams supplied by Allen Stanley in May 2005 from his extensive Rail Data Exchange.

These were the later of the Alco Ten-wheelers used in the MEC's passenger service. In addition to adding 2" of stroke to the earlier cylinder outfit, the class also had taller drivers. 288-289 had 19 1/2"-diameter cylinders, which increase tractive effort to 23,000 lb. They were delivered in pairs as indicated by their builder's numbers: 29723-29724, 30450-30451, 40081-40082.

Of the six in the class the first to retire was the 286, which was scrapped in April 1937. 285 and 288 were withdrawn in September 1938. The other three served throughout World War II.


Class O - 351 (Locobase 7057)

Data from MEC 2 - 1923 and MEC & PTC 7- 1947 Maine Central locomotive diagrams supplied by Allen Stanley in May 2005 from his extensive Rail Data Exchange. Works numbers were 27657-27659 and 29029-29030 in 1903) and 30323-30326, 38170-38173 in 1905.

Mixed-traffic engines like these Ten-wheelers were often the backbone of a small system's locomotive stud. Compared to other turn-of-the-century 4-6-0s, these locomotives had big boilers and grates, but a relatively low amount of direct heating surface.

This entry refers to the first thirteen, which had Stephenson valve gear. Schenectady supplied its production in small batches.

See Locobase 7058 for the Walschaert engines, which were built by Rhode Island.

All of this class were superheated beginning in 1916; see Locobase 15894.


Class O-1 (Locobase 7058)

Data from MEC 2 - 1923 and MEC & PTC 7- 1947 Maine Central locomotive diagrams supplied by Allen Stanley in May 2005 from his extensive Rail Data Exchange. Works numbers were 40576-40579 and 41235-41239.

Mixed-traffic engines like these Ten-wheelers were often the backbone of a small system's locomotive stud. This entry refers to the Walschaert engines delivered by the Ocean State's own Rhode Island Locomotive Works. 7057 shows the Schenectadies delivered with Stephenson link motion.

These may have been the engines that were originally intended for the Pittsburg, Binghamton & Eastern, a Bradford, Pa county railroad that encountered too many vicissitudes to ever actually begin serving any customers. (See Eleanor Parsons Keagle, "The PB & E-The Railroad That Never Ran", Elmira (NY) Telegram , 8 August 1955, hosted on Joyce M Tice's Tri-Counties Genealogy & History website ([], last accessed 10 July 2010).

All of this class were superheated beginning in 1916; see Locobase 15894.

The lower-numbered Stephenson-gear engines are shown in Locobase 7058.


Class O-1, O-2 superheated (Locobase 15894)

Data from MEC 2 - 1923 and MEC & PTC 7- 1947 Maine Central locomotive diagrams supplied by Allen Stanley in May 2005 and Dole's Maine Central Roster summary supplied in August 2013 from his extensive Rail Data Exchange.

Locobases 7057-7059 show the large stud of saturated-boiler Ten-wheelers as they were delivered in 1903 and 1907. Beginning in 1916, but applied to most locomotives in the mid-1920s, the MEC superheated the entire class to the same standard. The initial makeover was confined to the usual subtraction of small tubes to make way for superheater flues. Later, the railroad removed all of the arch tubes and installed two thermic syphons in the firebox. This added 51 sq ft (4.75 sq m) to the firebox heating surface area and raised it to 228 sq ft (21.2 sq m).

375 and 377 were scrapped in February 1939 while the others carried on through World War II. 381-382 went next in April 1947, 374 was scrapped in October, 376 followed almost 3 years later in June 1950. More than three years after that 380 (October) and 373, 379 (November) were sent to the boneyard.


Class O-2 (Locobase 7059)

Data from MEC 2 - 1923 and MEC & PTC 7- 1947 Maine Central locomotive diagrams supplied by Allen Stanley in May 2005 from his extensive Rail Data Exchange. Works numbers were 32267-32268, 32304 in November 1907; 32344, 32395, 32428 in December; 32566, 32575, 32644 in January 1908; and 32675 in February.

As the MEC added mixed-traffic Ten-wheelers, they went to several builders. Alco's Schenectady Works locomotives are shown in Locobase 7057. Those of the Rhode Island Works (also part of Alco by this time) appear in Locobase 7058.

In 1907, Baldwin added ten to the stud that had more but shorter boiler tubes. As a result, heating surface amounted to a little less than the Alcos.

All were superheated by the Maine Central beginning in 1916; see Locobase 15894.


Class O-3 (Locobase 7060)

Data from MEC 2 - 1923 and MEC & PTC 7- 1947 Maine Central locomotive diagrams supplied by Allen Stanley in May 2005 from his extensive Rail Data Exchange. Works numbers were 59050-59057 in 1917 and 62051-62054 in 1920.

A full decade after the last of the previous orders for Ten-wheelers had been delivered to the MEC (Locobase 7059), the railroad ordered eight more in 1917and followed these with four more in 1920 . The first eight may be credited to the exigencies of wartime, but the last quartet probably reflect more the relatively modest size of the MEC's mixed-traffic trains.

In addition to more adhesion weight (and engine weight, too), the new purchases featured larger cylinders, lower boiler pressure, an installed superheater, and taller drivers. Note as well the use of a third valve-gear design, the Baker gear on this group joining the earlier Stephenson link and Walschaert radial valve gears. Arch tubes contributed 26 sq ft (2.4 sq m) to the firebox heating surface.


Class O-4 (Locobase 15895)

Data from Dole's Maine Central roster supplied by Allen Stanley in August 2013 from his extensive Rail Data Exchange. Works numbers were 6482-6489 in May 1923.

From the relatively large Ten-wheelers Baldwin produced for the MEC in 1917, the railroad turned to Lima for lighter, somewhat less powerful 4-6-0s after World War One. They operated on the more lightly built sections east of Bangor, although even these engines had average axle loadings over 45,000 lb (20,412 kg).

All remained in service on the MEC throughout World War Two. Retirements and scrapping began in June 1949 and ended in December 1952.

Principal Dimensions by Steve Llanso of Sweat House Media
Class20 / G22/G4/GN-275N-283
Locobase ID12,815 11,433 2983 7056 7055
RailroadSomerset (MEC)Somerset (MEC)Washington County (MEC)Maine Central (MEC)Maine Central (MEC)
CountryUSAUSAUSAUSAUSA
Whyte4-6-04-6-04-6-04-6-04-6-0
Number in Class22594
Road Numbers20-2122-23/108-1094-8/31-35/110, 112-15275-283284-287, 288-289
GaugeStdStdStdStdStd
Number Built22594
BuilderBurnham, Williams & CoAlco-ManchesterBrooksAlco-SchenectadyAlco-Schenectady
Year19051907189818991904
Valve GearStephensonStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)10.08 / 3.0713.50 / 4.1114 / 4.2713 / 3.96
Engine Wheelbase (ft / m)20 / 6.1023.33 / 7.1124.17 / 7.3733.67 / 10.26
Ratio of driving wheelbase to overall engine wheebase 0.50 0.58 0.58 0.39
Overall Wheelbase (engine & tender) (ft / m)50.09 / 15.2751.50 / 15.7067 / 20.42
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)78,000 / 35,38087,500 / 39,68994,400 / 42,819107,000 / 48,534116,650 / 52,912
Engine Weight (lbs / kg)104,000 / 47,174113,000 / 51,256118,800 / 53,887140,600 / 63,775156,000 / 70,760
Tender Loaded Weight (lbs / kg)76,000 / 34,47378,00084,000 / 38,102108,700 / 49,306132,000 / 59,874
Total Engine and Tender Weight (lbs / kg)180,000 / 81,647191,000202,800 / 91,989249,300 / 113,081288,000 / 130,634
Tender Water Capacity (gals / ML)3600 / 13.643800 / 14.394000 / 15.155000 / 18.946000 / 22.73
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)6 / 5.50 8.50 / 7.709 / 8.2011 / 10
Minimum weight of rail (calculated) (lb/yd / kg/m)43 / 21.5049 / 24.5052 / 2659 / 29.5065 / 32.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 137255 / 139756 / 142269 / 175373 / 1854
Boiler Pressure (psi / kPa)180 / 12.40180 / 12.40180 / 12.40200 / 13.80200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)18" x 24" / 457x61018" x 24" / 457x61018" x 24" / 457x61019" x 24" / 483x61019" x 26" / 483x660
Tractive Effort (lbs / kg)22,032 / 9993.5621,631 / 9811.6721,245 / 9636.5821,346 / 9682.3921,858 / 9914.63
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.54 4.05 4.44 5.01 5.34
Heating Ability
Firebox Area (sq ft / m2)105.80 / 9.83134 / 12.45139.40 / 12.96115.70 / 10.75
Grate Area (sq ft / m2)24.10 / 2.2423.70 / 2.2021.80 / 2.0327.30 / 2.5440.50 / 3.76
Evaporative Heating Surface (sq ft / m2)1416 / 131.601620 / 150.561608 / 149.442089 / 194.142170 / 201.67
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1416 / 131.601620 / 150.561608 / 149.442089 / 194.142170 / 201.67
Evaporative Heating Surface/Cylinder Volume200.32229.18227.49265.24254.33
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation43384266392454608100
Same as above plus superheater percentage43384266392454608100
Same as above but substitute firebox area for grate area19,04424,12027,88023,140
Power L14458541481367839
Power MT378.01379.32502.90444.46

Principal Dimensions by Steve Llanso of Sweat House Media
ClassO - 351O-1O-1, O-2 superheatedO-2O-3
Locobase ID7057 7058 15,894 7059 7060
RailroadMaine Central (MEC)Maine Central (MEC)Maine Central (MEC)Maine Central (MEC)Maine Central (MEC)
CountryUSAUSAUSAUSAUSA
Whyte4-6-04-6-04-6-04-6-04-6-0
Number in Class139331012
Road Numbers351-363364-372350-382373-382401-412
GaugeStdStdStdStdStd
Number Built13131012
BuilderAlco-SchenectadyAlco-Rhode IslandMECBurnham, Williams & CoAlco-Schenectady
Year19031906191619071918
Valve GearStephensonWalschaertWalschaertWalschaertBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)14.83 / 4.5214.83 / 4.5214.83 / 4.5214.83 / 4.5214.83 / 4.52
Engine Wheelbase (ft / m)25.83 / 7.8725.83 / 7.8725.83 / 7.8725.83 / 7.8725.83 / 7.87
Ratio of driving wheelbase to overall engine wheebase 0.57 0.57 0.57 0.57 0.57
Overall Wheelbase (engine & tender) (ft / m)54.58 / 16.6454.58 / 16.6454.58 / 16.6455 / 16.7662 / 18.90
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)130,100 / 59,012134,500 / 61,008131,600 / 59,693138,300 / 62,732156,000 / 70,760
Engine Weight (lbs / kg)171,300 / 77,700172,000 / 78,018182,800 / 82,917182,800 / 82,917206,500 / 93,667
Tender Loaded Weight (lbs / kg)113,400 / 51,437113,400 / 51,437115,400 / 52,345115,000 / 52,163145,000 / 65,771
Total Engine and Tender Weight (lbs / kg)284,700 / 129,137285,400 / 129,455298,200 / 135,262297,800 / 135,080351,500 / 159,438
Tender Water Capacity (gals / ML)5400 / 20.455400 / 20.456000 / 22.735500 / 20.837500 / 28.41
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)10 / 9.1010 / 9.1010 / 9.1010 / 9.1011 / 10
Minimum weight of rail (calculated) (lb/yd / kg/m)72 / 3675 / 37.5073 / 36.5077 / 38.5087 / 43.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 160063 / 160063 / 160063 / 160067 / 1702
Boiler Pressure (psi / kPa)200 / 13.80200 / 13.80200 / 13.80200 / 13.80190 / 13.10
High Pressure Cylinders (dia x stroke) (in / mm)21" x 26" / 533x66021" x 26" / 533x66021" x 26" / 533x66021" x 26" / 533x66022" x 28" / 559x711
Tractive Effort (lbs / kg)30,940 / 14034.1630,940 / 14034.1630,940 / 14034.1630,940 / 14034.1632,666 / 14817.07
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.20 4.35 4.25 4.47 4.78
Heating Ability
Firebox Area (sq ft / m2)177.20 / 16.47177.20 / 16.47206 / 19.14160 / 14.87189 / 17.57
Grate Area (sq ft / m2)46 / 4.2846 / 4.2845 / 4.1845 / 4.1845 / 4.18
Evaporative Heating Surface (sq ft / m2)3053 / 283.743053 / 283.742284 / 212.192972 / 276.212334 / 216.91
Superheating Surface (sq ft / m2)450 / 41.81529 / 49.16
Combined Heating Surface (sq ft / m2)3053 / 283.743053 / 283.742734 / 2542972 / 276.212863 / 266.07
Evaporative Heating Surface/Cylinder Volume292.91292.91219.13285.14189.46
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation92009200900090008550
Same as above plus superheater percentage9200920010,440900010,089
Same as above but substitute firebox area for grate area35,44035,44047,79232,00042,374
Power L17936793614,837760013,847
Power MT403.44390.24745.67363.45587.06

Principal Dimensions by Steve Llanso of Sweat House Media
ClassO-4
Locobase ID15,895
RailroadMaine Central (MEC)
CountryUSA
Whyte4-6-0
Number in Class8
Road Numbers383-390
GaugeStd
Number Built8
BuilderLima
Year1923
Valve GearBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)14.83 / 4.52
Engine Wheelbase (ft / m)25.83 / 7.87
Ratio of driving wheelbase to overall engine wheebase 0.57
Overall Wheelbase (engine & tender) (ft / m)58.46 / 17.82
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)136,000 / 61,689
Engine Weight (lbs / kg)182,000 / 82,554
Tender Loaded Weight (lbs / kg)137,000 / 62,142
Total Engine and Tender Weight (lbs / kg)319,000 / 144,696
Tender Water Capacity (gals / ML)6500 / 24.62
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)10 / 9.10
Minimum weight of rail (calculated) (lb/yd / kg/m)76 / 38
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 1600
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)20" x 28" / 508x711
Tractive Effort (lbs / kg)30,222 / 13708.48
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.50
Heating Ability
Firebox Area (sq ft / m2)165 / 15.33
Grate Area (sq ft / m2)44.70 / 4.15
Evaporative Heating Surface (sq ft / m2)2005 / 186.27
Superheating Surface (sq ft / m2)440 / 40.88
Combined Heating Surface (sq ft / m2)2445 / 227.15
Evaporative Heating Surface/Cylinder Volume196.93
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation8940
Same as above plus superheater percentage10,549
Same as above but substitute firebox area for grate area38,940
Power L114,005
Power MT681.08

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