Boston & Maine / Fitchburg 2-8-0 "Consolidation" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 26-31 (Locobase 12308)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 20, p. 291. Works numbers were 16296-16301 in November 1898.

In 1898, Baldwin persuaded the Fitchburg to turn in 6 of its older Consoldiations for reconstruction as Vauclain compounds. The specs show these old numbers:

Original # 1898 # Year built Builder Works Specs # 1899 #

192 108 1889 Rhode Island 2275 26 410

111 111 1886 Rhode Island 1645 27 412

114 114 1887 Taunton 941 28 413

187 103 1889 Rhode Island 2270 29 409

110 110 1886 Rhode Island 1644 30 411

117 117 1887 Taunton 944 31 414

Baldwin's workover is well documented in the spec book, which includes showing the dozens of components that were repaired or replaced. The installation resulted in a compound locomotive of typical proportions and 11 1/2" (292 mm) piston valves. Haulage capacity was set at 935 tons.

Accompanying the specs was a long statement of Baldwin's promise: "Guaranteed with equal or greater efficiency to develop an economy of operation of at least 10% over similar single-expansion Engs." Baldwin would supply all the "necessary parts" and would pay all labor costs to convert to simple-expansion if this goal was not met during the first year. The company also guaranteed the tightness of their boilers to 200 psi for 5 years and against staybolt leakage "as long as the original parts are in use."

In the event, the Fitchburg was taken into the Boston & Maine, which rebuilt the entire class in 1902 (3) and 1905 (3) as 20" x 24"simple-expansion locomotives. By then the guarantee had expired, but most US roads had begun to take similar steps by then.

Redesignated K4a (K4c in the case of the 1074/2307), the class operated into the latter half of the 1920s. 2308 was scrapped first in November 1926 and 2304 went last in September 1928.


Class K-5a, 5b (Locobase 4123)

Data from B&M 6 - 1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange; and "Some Schenectady Consolidations", Railroad Gazette. Volume XXXIII [33], No 14 (5 April 1901), p. 233-234. Works numbers were 5748-5754 in January 1901, 5755-5757 in February, 5820-5829 in March. Following the assembly of the American Locomotive Company works, the new sequence continued with 25053-25061 in March 1902, and 25062-25066 in May

Schenectady delivered this batch of simple-expansion consolidations that used a boiler common to many B&M 2-8-0s from the New York builder in the early years of the 20th Century. As of April 1901, ten had been delivered and had gone to work on the Fitchburg Division. Eventually, the class roamed all over the system.

They were retired during the 1926-1936 decade.


Class K-5d, K-7b/c-superheated (Locobase 6627)

Data from 1927 and 1947 Boston & Maine Description of Locomotives books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

When the K-7 engines shown in Locobase 2382 were superheated, this was the result. As usual in such conversions, the shops sacrificed 161 small tubes--about half--to make room for the 24 flues that held the superheater elements. No need to change valve setups as these were delivered with 11" (279 mm) piston valves.

The refit supplied drier steam that more than made up for shorter tubes and the 16% loss in overall heating surface.

Eight of the superheated engines enjoyed second and, in some cases, third careers. In February and October 1930, 2420 and 2401 wound up on the Montpelier & Wells River as their 18-19. In 1945, the 19 went to the Barre & Chelsea.The 18 had already gone to the Saint Johnsbury & Lake Champlain in 1939 as their road #40.

June 1932 saw the sale of four (2421, 2427 2404, and 2425) in 1930 and 1932 to the Saint Johnsbury & Lake Champlain as their 34-37.

Much later, the 2412 was sold to the Barre & Chelsea in August 1946, where it was renumbered 22..Slightly more than a year later, the 22 joined its former stablemates at the Saint Johnsbury & Lake Champlain as road # 43.


Class K-6 (Locobase 3274)

Data from "Practical Reconstruction of Old Locomotives," Railway Age, Volume 70, No. 3 (21 Jan 1921) , pp.237-239. Works numbers were 25052 in November 1901, 25067-25075 in April 1902.

These cross-compound Consoldations ran for the better part of two decades before being rebuilt as simples. The high-pressure cylinder (left side, facing forward) took steam through a piston valve, while the low-pressure one (right side) was supplied through a slide valve.

Reconstruction as simple-expansion engines began in 1920; see Locobase 3275.


Class K-6 simpled, superheated (Locobase 3275)

As "Practical Reconstruction of Old Locomotives," Railway Age, Volume 70, No. 3 (21 January 1921) , pp.237-239. noted in its coverage of rebuilding programs on the Boston & Maine, "It can easily be imagined just how unsatisfactory a saturated steam cross-compound Consolidation type locomotive of these dimensions [Locobase 3274] would prove under modern conditions, both from an operating and maintenance standpoint."

Notice where the changes were made: Cylinder stroke was shortened by two inches (50.8 mm), and both now had piston valves actuated by Walschaerts radial gear. Total heating surface shrank by 370 sq ft (34.37 sq m), but the steam was now superheated when it reached the cylinders. Weight grew only slightly and the grate was untouched.

The rebuild added about 10-15 years to the design's life and the class retired between 1928 and 1935.


Class K-7 (Locobase 2382)

Data from 1927 and 1947 Boston & Maine Description of Locomotives books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.Works numbers were 39642-39651 in October 1906, 44374-44379 in November 1907, 44380-44383 in December, 49000-49008 in January 1910 49009 in February; 47644-47648, 47657-47663 in May, and 47649-47656 in June.

This was the smaller of the two main Consolidation classes operated by the B&M. Like the other B&M 2-8-0s, these were delivered with 11" (279 mm) piston valves.

Those that were not superheated (see Locobase 6627) were scrapped in the 1920s and 1930s.


Class K-8a - saturated boiler (Locobase 3276)

Data from DeGolyer, Volume 38, pp. 178+. Works numbers were 36260-36263, 36296-36299, 36303-36306, 36317-36319 in March 1911; 36382-36393, 36427-36429, 36470-36479 in April.

A notably large class of Consolidations began with these saturated Philadelphians. The design used 12" (305 mm) piston valves, but saturated steam. Firebox heating surface included 25 sq ft (2.3 sq m) of arch tubes.

This class superheated in a 1916 rebuild; see K-8/superheated (Locobase 3277).


Class K-8a-d - superheated (Locobase 3277)

Data from 1927, 1939, and 1947 Boston & Maine Description of Locomotives books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Practical Reconstruction of Old Locomotives," Railway Age, Volume 70, No. 3 (21 January 1921) , pp.237-239; "2-8-0 Type of Locomotive for the Boston & Maine", Railway and Locomotive Engineering, Volume 26, No 6 (June 1913), p. 215; and DeGolyer, Volume 43, pp. 11+. .(Thanks to Chris Hohl for his 6 January 2018 email and spreadsheet spelling out some of the details of these engines.)

Baldwin's works numbers were 39287-39295, 39327-39338; 39355-39365 in February 1913; 39397-39414 in March. Alco's Schenectady works added 20 K-8b class 53251-53270 as road numbers 2690-2709 in March 1913. Alco's Brooks supplied 25 K-8c (works numbers 56541-56465) as road numbers 2710-2734 in 1916.

After delivering the first 40 K-8s in 1911 with saturated boilers (Locobase 3276), Baldwin produced 50 more Consolidations with superheaters. Baldwin's specs as shown in the specification book differed slightly from those shown in the B&M Descriptions.

The Schenectady engines that completed the class and the first Baldwins were superheated in 1916; Chris Hohl notes that the latter were then reclassified as K-8d. Railway Age reveals the subtle differences that went into superheating the rest of this large class of Consolidations along the lines of the Baldwins. Cylinder size grew by two inches (50.8 mm). The boiler was rearranged to accept 30 superheater elements, while working boiler pressure was eased by 20 psi (1.85 bar). The designers obviously felt that the more potent dry steam would allow them to back off on the pressure to improve reliability. Piston valve diameter measured 12" (305 mm).

Locobase 16338 shows the next round of updates that included feed water heaters and thermic syphons.


Class K-8b-d - syphons (Locobase 16338)

Data from 1927, 1939, and 1947 Boston & Maine Description of Locomotives books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection.

The first round of B&M superheated K-8s (Locobase 3277) did little but alter the boiler innards to make room for the 30 flues that held the superheater elements.

In the late 1920s and early 1930s, most of the class received feed water heaters as follows:

Elesco K-24 reciprocating Worthington 3BL

K-8b 24 20

K-8c 6 17

K-8d 3 4

The 1928 book shows eight fewer boiler tubes than the 204 counted in the first update. The discrepancy is explained by noting that by that time, the firebox had been reworked with 62.5 sq ft (5.8 sq m) of thermic syphons and only one arch tube of 12.6 sq ft (1.15 sq m); these areas are included in the firebox heating surface.

The rebuilds ran on for years, with the first retirements beginning in 1937, but not ending until 1954. Bangor & Aroostook bought two in 1946."

Principal Dimensions by Steve Llanso of Sweat House Media

Class26-31K-5a, 5bK-5d, K-7b/c-superheatedK-6K-6 simpled, superheated
Locobase ID12308 4123 6627 3274 3275
RailroadFitchburg (B&M)Boston & Maine (B&M)Boston & Maine (B&M)Boston & Maine (B&M)Boston & Maine (B&M)
CountryUSAUSAUSAUSAUSA
Whyte2-8-02-8-02-8-02-8-02-8-0
Number in Class634661010
Road Numbers23-31 / 409-414 / 1070-1075 /1141-1175/2310-23432360-24291161, 1176-1184/2350-23592350-2359
GaugeStdStdStdStdStd
Number Built6346610
BuilderBurnham, Williams & CoSchenectadyB&MAlco-SchenectadyB & M
Year18981901192019011920
Valve GearStephensonStephensonWalschaertmixedWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.83 / 4.8217 / 5.1817 / 5.1817 / 5.1817 / 5.18
Engine Wheelbase (ft / m)23.67 / 7.2125.50 / 7.7725.50 / 7.7725.50 / 7.7725.50 / 7.77
Ratio of driving wheelbase to overall engine wheelbase 0.67 0.67 0.67 0.67 0.67
Overall Wheelbase (engine & tender) (ft / m)53.8153.86 / 16.42
Axle Loading (Maximum Weight per Axle) (lbs / kg)37,900 / 17,191
Weight on Drivers (lbs / kg)121,000 / 54,885142,000 / 64,410151,600 / 68,765150,000 / 68,039153,000 / 69,400
Engine Weight (lbs / kg)141,000 / 63,957162,000 / 73,482176,600 / 80,105175,000 / 79,379178,000 / 80,740
Tender Loaded Weight (lbs / kg)118,000 / 53,524115,000
Total Engine and Tender Weight (lbs / kg)294,600 / 133,629293,000
Tender Water Capacity (gals / ML)5000 / 18.945000 / 18.945000
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)10 / 914 / 1312
Minimum weight of rail (calculated) (lb/yd / kg/m)50 / 2559 / 29.5063 / 31.5063 / 31.5064 / 32
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56 / 142261 / 154961 / 154961 / 154961 / 1549
Boiler Pressure (psi / kPa)200 / 13.80200 / 13.80200 / 13.80200 / 13.80200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)15" x 24" / 381x61020" x 30" / 508x76220" x 30" / 508x76222" x 32" / 559x813 (1)20" x 30" / 508x762
Low Pressure Cylinders (dia x stroke) (in / mm)25" x 24" / 635x61035" x 32" / 889x813 (1)
Tractive Effort (lbs / kg)24,107 / 10934.7633,443 / 15169.5133,443 / 15169.5130,939 / 14033.7133,443 / 15169.51
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.02 4.25 4.53 4.85 4.57
Heating Ability
Tubes (number - dia) (in / mm)285 - 2" / 51326 - 2" / 51165 - 2" / 51326 - 2" / 51165 - 2" / 51
Flues (number - dia) (in / mm)24 - 5.375" / 13724 - 5.375" / 137
Flue/Tube length (ft / m)11.50 / 3.5116 / 4.8815.79 / 4.8116 / 4.8816 / 4.88
Firebox Area (sq ft / m2)110 / 10.22157 / 14.59158 / 14.68143 / 13.29143 / 13.29
Grate Area (sq ft / m2)29.25 / 2.7246.51 / 4.3246.50 / 4.3246.04 / 4.2846.04 / 4.28
Evaporative Heating Surface (sq ft / m2)1814 / 168.592875 / 267.092046 / 190.082860 / 265.802060 / 191.45
Superheating Surface (sq ft / m2)437 / 40.60431 / 40.06
Combined Heating Surface (sq ft / m2)1814 / 168.592875 / 267.092483 / 230.682860 / 265.802491 / 231.51
Evaporative Heating Surface/Cylinder Volume369.86263.52187.53406.07188.82
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation58509302930092089208
Same as above plus superheater percentage5850930210,974920810,773
Same as above but substitute firebox area for grate area22,00031,40037,28828,60033,462
Power L13236682112,616408012,401
Power MT235.84423.60733.87239.86714.76

Principal Dimensions by Steve Llanso of Sweat House Media

ClassK-7K-8a - saturated boilerK-8a-d - superheatedK-8b-d - syphons
Locobase ID2382 3276 3277 16338
RailroadBoston & Maine (B&M)Boston & Maine (B&M)Boston & Maine (B&M)Boston & Maine (B&M)
CountryUSAUSAUSAUSA
Whyte2-8-02-8-02-8-02-8-0
Number in Class66408484
Road Numbers2360-24292600-26392600-27242600-2724
GaugeStdStdStdStd
Number Built664050
BuilderAlco-SchenectadyBaldwinBaldwinB&M
Year1906191119161924
Valve GearWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)17 / 5.1817 / 5.1817 / 5.1817 / 5.18
Engine Wheelbase (ft / m)25.50 / 7.7726 / 7.9226 / 7.9226 / 7.92
Ratio of driving wheelbase to overall engine wheelbase 0.67 0.65 0.65 0.65
Overall Wheelbase (engine & tender) (ft / m)53.86 / 16.4259 / 17.9858.17 / 17.7058.06 / 17.70
Axle Loading (Maximum Weight per Axle) (lbs / kg)37,900 / 17,19152,500 / 23,81449,806 / 22,592
Weight on Drivers (lbs / kg)148,000 / 67,132182,000 / 82,554186,060 / 84,395190,600 / 86,455
Engine Weight (lbs / kg)170,000 / 77,111205,000 / 92,987211,000 / 95,708216,100 / 98,021
Tender Loaded Weight (lbs / kg)118,000 / 53,524147,000 / 66,678139,000 / 63,049139,000 / 63,049
Total Engine and Tender Weight (lbs / kg)288,000 / 130,635352,000 / 159,665350,000 / 158,757355,100 / 161,070
Tender Water Capacity (gals / ML)5000 / 18.947000 / 26.527300 / 27.657300 / 27.65
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)14 / 1312 / 1112 / 1112 / 11
Minimum weight of rail (calculated) (lb/yd / kg/m)62 / 3176 / 3878 / 3979 / 39.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)61 / 154961 / 154961 / 154961 / 1549
Boiler Pressure (psi / kPa)200 / 13.80220 / 15.20180 / 12.40180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)20" x 30" / 508x76222" x 30" / 559x76224" x 30" / 610x76224" x 30" / 610x762
Tractive Effort (lbs / kg)33,443 / 15169.5144,512 / 20190.3343,342 / 19659.6243,342 / 19659.62
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.43 4.09 4.29 4.40
Heating Ability
Tubes (number - dia) (in / mm)326 - 2" / 51366 - 2" / 51204 - 2" / 51196 - 2" / 51
Flues (number - dia) (in / mm)30 - 5.375" / 13730 - 5.375" / 137
Flue/Tube length (ft / m)16 / 4.8815.67 / 4.7814.75 / 4.5014.75 / 4.50
Firebox Area (sq ft / m2)158 / 14.68204 / 18.95207 / 19.23247.10 / 22.96
Grate Area (sq ft / m2)46.50 / 4.3253.40 / 4.9653.24 / 4.9553.24 / 4.95
Evaporative Heating Surface (sq ft / m2)2860 / 265.803161 / 293.662392 / 222.222392 / 222.22
Superheating Surface (sq ft / m2)522 / 48.49501 / 46.54
Combined Heating Surface (sq ft / m2)2860 / 265.803161 / 293.662914 / 270.712893 / 268.76
Evaporative Heating Surface/Cylinder Volume262.14239.47152.26152.26
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation930011,74895839583
Same as above plus superheater percentage930011,74811,30811,212
Same as above but substitute firebox area for grate area31,60044,88043,96752,039
Power L16803708494659478
Power MT405.35343.24448.60438.52

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