Boston & Maine / Fitchburg 2-8-0 "Consolidation" Locomotives of 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" 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-5 (Locobase 4123)

Data from B&M 6 - 1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

A batch of simple-expansion consolidations that 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 Raildata collection.

When the K-7 engines shown in Locobase 2382 were superheated, this was the result. Drier steam supplied through 11"(279 mm) piston valves more than made up for shorter tubes and the 16% loss in overall heating surface.


Class K-6 (Locobase 3274)

Data from "Practical Reconstruction of Old Locomotives," Railway Age, Volume 70, No. 3 (21 Jan 1921) , pp.237-239.

These cross-compounds 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.


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 Raildata collection.

This was the smaller of the two main Consolidation classes operated by the B&M. 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/b/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 Raildata collection. See also "Practical Reconstruction of Old Locomotives," Railway Age, Volume 70, No. 3 (21 Jan 1921) , pp.237-239.Baldwin's works numbers were 39287-39295, 39327-39338; 39355-39365 in February 1913; 39397-39414 in March.

After delivering the first 40 K-8s in 1911 with saturated boilers (Locobase 3276), Baldwin produced 50 more Consolidations with superheaters.

The Schenectady engines that completed the class and the first Baldwins were superheated in 1916. 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 40 psi (2.75 bar). The designers obviously felt that the more potent dry steam would allow them to back off on the pressure to improve reliability.

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 1939 and 1947 books show eight fewer boiler tubes than the 204 counted in the 1921 article. 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 syphon 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 2 in 1946.

Specifications by Steve Llanso of Sweat House Media
Class26-31K-5K-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 /2310-23432360-24292350-23592350-2359
GaugeStdStdStdStdStd
Number Built6346610
BuilderBurnham, Williams & CoAlco-SchenectadyB&MAlco-SchenectadyB & M
Year1898190119011920
Valve GearStephensonStephensonWalschaertmixedWalschaert
Locomotive Length and Weight
Driver Wheelbase15.83'17'17'17'17'
Engine Wheelbase23.67'25.50'25.50'25.50'25.50'
Ratio of driving wheelbase to overall engine wheebase 0.67 0.67 0.67 0.67 0.67
Overall Wheelbase (engine & tender)53.86'
Axle Loading (Maximum Weight per Axle)37900 lbs
Weight on Drivers121000 lbs142000 lbs151600 lbs150000 lbs153000 lbs
Engine Weight141000 lbs162000 lbs176600 lbs175000 lbs178000 lbs
Tender Light Weight118000 lbs115000 lbs
Total Engine and Tender Weight294600 lbs293000 lbs
Tender Water Capacity5000 gals5000 gals5000 gals
Tender Fuel Capacity (oil/coal)10 tons14 tons tons12 tons
Minimum weight of rail (calculated)50 lb/yard59 lb/yard63 lb/yard63 lb/yard64 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter56"61"61"61"61"
Boiler Pressure200 psi200 psi200 psi200 psi200 psi
High Pressure Cylinders (dia x stroke)15" x 24"20" x 30"20" x 30"22" x 32"20" x 30"
Low Pressure Cylinders (dia x stroke)25" x 24" (2)35" x 32" (1)
Tractive Effort24107 lbs33443 lbs33443 lbs30939 lbs33443 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.02 4.25 4.53 4.85 4.57
Heating Ability
Firebox Area110 sq. ft157 sq. ft158 sq. ft143 sq. ft143 sq. ft
Grate Area29.25 sq. ft46.51 sq. ft46.50 sq. ft46.04 sq. ft46.04 sq. ft
Evaporative Heating Surface1814 sq. ft2875 sq. ft2046 sq. ft2860 sq. ft2060 sq. ft
Superheating Surface437 sq. ft431 sq. ft
Combined Heating Surface1814 sq. ft2875 sq. ft2483 sq. ft2860 sq. ft2491 sq. ft
Evaporative Heating Surface/Cylinder Volume369.55263.56187.56406.28188.85
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation58509302930092089208
Same as above plus superheater percentage5850930210974920810773
Same as above but substitute firebox area for grate area2200031400372882860033462
Power L13236682212618408012403
Power MT235.84423.66733.98239.86714.87

Specifications by Steve Llanso of Sweat House Media
ClassK-7K-8a - saturated boilerK-8a/b/superheated
Locobase ID2382 3276 3277
RailroadBoston & Maine (B&M)Boston & Maine (B&M)Boston & Maine (B&M)
CountryUSAUSAUSA
Whyte2-8-02-8-02-8-0
Number in Class664084
Road Numbers2360-24292600-26392600-2724
GaugeStdStdStd
Number Built664050
BuilderAlco-SchenectadyBaldwinBaldwin
Year190519111916
Valve GearWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase17'17'17'
Engine Wheelbase25.50'26'26'
Ratio of driving wheelbase to overall engine wheebase 0.67 0.65 0.65
Overall Wheelbase (engine & tender)53.86'59'58.06'
Axle Loading (Maximum Weight per Axle)37900 lbs52500 lbs
Weight on Drivers148000 lbs182000 lbs197100 lbs
Engine Weight170000 lbs205000 lbs222500 lbs
Tender Light Weight118000 lbs147000 lbs152900 lbs
Total Engine and Tender Weight288000 lbs352000 lbs375400 lbs
Tender Water Capacity5000 gals7000 gals7300 gals
Tender Fuel Capacity (oil/coal)14 tons12 tons16 tons
Minimum weight of rail (calculated)62 lb/yard76 lb/yard82 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter61"61"61"
Boiler Pressure200 psi220 psi180 psi
Cylinders (dia x stroke)20" x 30"22" x 30"24" x 30"
Tractive Effort33443 lbs44512 lbs43342 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.43 4.09 4.55
Heating Ability
Firebox Area158 sq. ft204 sq. ft247.10 sq. ft
Grate Area46.50 sq. ft53.40 sq. ft53.24 sq. ft
Evaporative Heating Surface2860 sq. ft3161 sq. ft2369 sq. ft
Superheating Surface520 sq. ft
Combined Heating Surface2860 sq. ft3161 sq. ft2889 sq. ft
Evaporative Heating Surface/Cylinder Volume262.19239.49150.82
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation9300117489583
Same as above plus superheater percentage93001174811308
Same as above but substitute firebox area for grate area316004488052484
Power L1680470859652
Power MT405.41343.29431.84

Photos

Reference


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