West Virginia Central & Pittsburgh / Western Maryland 2-8-0 "Consolidation" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 27/H-3 (Locobase 12019)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 17, p. 210. Works number was 12467 in February 1892.

This WVC Consolidation served both the WVC and its successor Western Maryland unremarkably for 25 years.* In June 1916, it was sold to the evocatively named Reliable Junk Company. (Locobase notes the odd juxtaposition of "reliable" and "junk"...)


Class 30 / H-3f (Locobase 8872)

Data from WM 1 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange; see also Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 20, p. 67.. Works numbers were 14390 in August 1895; 14555-5 in November; 15538 in October 1897 and 15872-73 in April 1898.

Locobase 2101 shows a Coal & Coke design from 1904 that sported the same dimensions, weights, and areas as did this sextet. As both classes operated in the West Virginia coal regions, it isn't surprising that the two would be so similar.

Whereas the Coal & Cokes eventually worked for the Baltimore & Ohio, however, all of the locomotives passed into the Western Maryland when that road bought the WVC & P in 1905; they were dubbed H-3f.

All but one of the class was scrapped in 1924-1928. The #30 was sold to the 72-mile-long Huntingdon & Broad Top Mountain in September 1947.


Class 37 / H-3g (Locobase 12385)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 22, p. 209. Works number was 17431 in February 1900.

37 had an ever so slight difference in the length of the tubes in its boiler from the five 1895 Consolidations described in Locobase 8872. Undoubtedly, there were other significant differences, although a review of the specs for the earlier locomotives fails to reveal them. the five-year difference in production date was enough for the Western Maryland, which placed 37, now 357, in its own subclass.

357 was retired in June 1925.


Class 45 / H-3a / H-3b (Locobase 12001)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 17, p. 131. Works number was 12286 in October 1891.

This Vauclain compound featured two 10 1/2" (267 mm) piston valves, each feeding both the HP and LP cylinders on a side. A second engine with 22" LP cylinders had been produced as a demonstrator (works number 12286) in October 1891 and numbered 127. It was sold late in 1891 to Western Maryland as their #49; see DeGolyer, Volume 17, p. 214.

n a later year, the WM converted the 45 into a simple-expansion 19" x 26".


Class 58/H-3b (Locobase 12243)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 21, p. 83. Works numbers 15590-15595 in November 1897 and 16012-16015 in June 1898.

Relatively small Consolidations came on the WM at the end of the 19th Century.

Scrapping began in 1923 with 325 and 321-323 closed out the class in 1926-1927.


Class H-3-c (Locobase 8871)

Data from WM 1 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 12794 and 12803 in July 1892.

This pair of Consolidations was delivered in 1892 as Vauclain compounds (Locobase 16164). They were simpled sometime later.

347 was sold to the Virginia Central in June 1920 as their 347. The VC scrapped the engine in 1938. 348 endured on the WM, only going to the scrapyard in October 1952.


Class H-3-c (Locobase 16164)

Data from WM 1 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 18, p. 17 . Works numbers were 12794 and 12803 in July 1892.

Ordered during the first years of the Vauclain compound's popularity, this pair of Consolidations had relatively short strokes and their 10 1/2" (267 mm) piston valves were small compared to later installations. Discussion of how to confirm their theoretical superiority to simple engines appeared in journals regularly and one commentator said to simply put a few dozen in service. An unrelated letter in the 23 June 1892 Engineering News (p. 633) stated that the highest point on a railroad east of the Mississippi was found crossing Kent Ridge 1 1/2 miles north of Davis City on the WVC, which suggests a suitably challenging environment for these locomotives.

They were later simpled; see Locobase 8871.


Class H-4-b (Locobase 8875)

Data from WM 1 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 23, p. 17 and Volume 25, p. 223. Works 17731-32 in May 1900, 18730-31 in March 1901; 21696, 21738 in March 1903; and 21978, 22009 in April.

All of these Consolidations were delivered with Stephenson valve gear, but at least, engine 455, was later fitted with Baker radial gear. Like the other WVC & P 2-8-0s, these were low-drivered freight haulers. And like the others, they came into the Western Maryland in November 1905.

The class met varied fates. 453 was scrapped in February 1928, 452 was sold to Vang Construction Company in February 1929 and scrapped in 1931.

454-456 were sold in 1930 to the Greenbrier, Cheat & Elk Railroad as their 118-119. 118 relettered in November for its owner, Pardee & Curtin Lumber Company. 119 had power reverse installed in 1933 Both regained their WM affiliation and road numbers in 1936 and served until scrapped in 1947 and December 1946.

457-458 were scrapped in January and December 1947, respectively, and 451 went to the ferro-knacker in May 1950. 455 was rebuilt in 1923 and operated until June 1953.


Class H-4/H-4-a (Locobase 8873)

Data from WM 1 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 23, p. 289 and Volume 25, p. 215. Works numbers were 18879-18881,18912-18918 in April 1901 and 21606, 21639, 21682, 21686, 21698, 21711 in February 1903.

One of a series of 2-8-0 designs built for the Western Maryland, most by Baldwin. Some sources credit this set of 16 originally to the West Virginia Central & Pittsburgh, but the Baldwin specifications show Western Maryland as the original purchaser. The specs noted that the tubes were to be spaced to create a 3/4" (19 mm) circulation space around each tube.

Most of the class was retired between 1927 and 1931. Class leader 401 took on a short new career in 1930 as Chesapeake Beach Railway's #10 before it was scrapped in 1935. 409 also went to the CBR as their #9, but was returned to the Western Maryland. Chesapeake Beach was a resort town about 35 miles (56 km) south east of Washington, DC on the western shore of Chesapeake Bay. While the first impulse to build a railway to the proposed site came in 1871, the railroad that was finally built took shape in the 1890s, finally opening in 1901 when the resort was actually completed. It never made money and was on its way to abandonment when the 9 and the 10 operated briefly on its rails. The last train finished its run on 15 April 1935.

When the WM began work on its Connellsville Extension, it sold 404, 407, 411, and 415 to Vang Construction Company. 407 was soon scrapped in 1930 and 415 followed in 1931.

406 and 416 survived until 1941 and 1946, respectively.


Class H-5 (Locobase 1408)

Data from WM 1 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 28, p. 134. Works numbers were 26617, 26635 in October 1905; 26788, 26834-26835, 26857, 26874, 26897, 26915-26918, 26939-26940 in November; 26956-26958, 26979, 26980 in December.

One of a series of 2-8-0 designs built for the Western Maryland, most by Baldwin. Compared to the H-4 class from 1901 (Locobase 8873), this class had smaller drivers and higher steam pressure, which boosted their starting tractive effort. Perhaps the main reason for smaller drivers and the larger boiler was the 10 mile grade that rose a 156 feet to the mile (2.95%). The greater boiler diameter was dictated not only by the increased number of tubes, but also the desire to preserve a 3/4" (19 mm) circulation space among them.

The eighteen engines in this class were retired over a 17-year period from 1927 to 1944. Several -- 501, 506-507, 509, 513, 518 -- were sold in 1930 to the Greenbrier, Cheat & Elk logging road (then a part of the Western Maryland) as 124, 120-121, 125, 123, and 122, respectively. The WM got them back in 1934 with their original numbers.


Class H-6 (Locobase 1409)

Data from WM 1 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 30, p. 173. Works numbers were 29870-29874 in December 1906; 29936-29939, 29958-29961, 29964, 29973-29975, 30014 in January 1907; 30079, 30120, 33204-33211, 33222-33223 in February.

One of a series of 2-8-0 designs built for the Western Maryland, most by Baldwin. Built over a three-year period, the H-6 improved on the H-5 by enlarging the cylinders and increasing driver diameter. Both the boiler and grate substantially increased in surface area, well beyond a simple scaling up based on a cylinder-volume ratio. Placing the grate above the drivers allowed for a significant increase in the firebox width, which grew from 42"(1,067 mm) to 70" (1,778 mm). Outside radial valve gear replaced the inside Stephenson link motion used in earlier engines as well.

These 30 engines in this class were retired beginning 1927, although most were converted to 0-8-0s in the C-1/C-2 classes. Some survived World War II and the 616 was sold to the Winfield Railroad of West Winfield , Pa as their #4 in January 1947.


Class H-6A (Locobase 8320)

Data from WM Misc Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Locobase 1409 shows the original form of this decade of Consolidations from 1909. Four of the class underwent the upgrade that reduced the tube count by 21 while adding significantly to the firebox heating surface through the introduction of thermic syphons.

Despite the tweaks, the quartet joined most of the other H-6s in surrendering their leading trucks to become 0-8-0 switchers. 625, renumbered 1052, formed part of C-1A class. The other three were dubbed C-2A and took road numbers 1071-1073.


Class H-7 (Locobase 1410)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 41, p. 319. (Thanks to Chris Hohl for his 27 August 2015 email reporting the original tender weights and capacities.) Baldwin's works numbers were 35153-35155 in August 1910; 35211-35213 in September.

One of a series of 2-8-0 designs built for the Western Maryland. Again, the changes included enlarging the cylinders and increasing driver diameter. These engines were also 16 tons heavier than the H-6s (Locobase 1409). In the 1910 specifications, tender loaded weight was 130,000 lb (58,967 kg) when carrying 7,000 US gallons (26,495 litres) of water and 12 short tons (13.2 tonnes) of coal. The tender specs shown in the Locobase table reflect capacity increases typical for a US trunk line.

Alco's version of the H-7 was the H-7a, the superheated upgrade of which is shown in Locobase 1411.

Retirements began in July 1930 when 705 was sold to the Tennessee Railroad. The other five were all scrapped in 1936.


Class H-7a (Locobase 1411)

One of a series of 2-8-0 designs built for the Western Maryland, but the first of two classes built by Alco. These -7bs added an inch to cylinder diameter and were 9,000 lb heavier than the H-7s. They also served as the template for the K-2 Pacifics built by Baldwin in 1912 (Locobase 175), whose parts were expressly required to be interchangeable with these Alcos.

When superheated, they retained the 9" piston valves (with 6" travel) of the original design.

The last in the class to retire went in 1954.


Class H-7a/b - superheated syphons (Locobase 8887)

Data from WM 1 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Locobase 1410 shows the superheated version of the original H-7 Consolidation. This entry describes the effect of fitting syphons to the firebox. The frame was extended by 5" (127 mm). The combined increase in direct heating surface and 14" (356 mm) piston valves probably contributed to a significant improvement in power.


Class H-7b (Locobase 13937)

One of a series of 2-8-0 designs built for the Western Maryland, but the first of two classes built by Alco. Works numbers were 51396-51402, 51404-51406, 51408-51411. These -7bs added an inch to cylinder diameter and were 9,000 lb heavier than the H-7s. Locobase 1411 has the H-7a delivered by Richmond

They also served as the template for the K-2 Pacifics built by Baldwin in 1912 (Locobase 175), whose parts were expressly required to be interchangeable with these Alcos.

When superheated, they retained the 9" piston valves (with 6" travel) of the original design.

The last in the class to retire went in 1954.


Class H-8 (Locobase 1412)

Data from May 1916 RME table, amended and supplemented by WM 1 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Consolidation Locomotives for the Western Maryland Railway," Volume 55, (1 August 1914), pp. 124-126. (Thanks to Chris Hohl for his 3 April 2015 email correcting the valve gear.) Works numbers were 54540-54559 in February 1914.

One of a series of 2-8-0 designs built for the Western Maryland, these reverted to small drivers. The result was low speed, but greater tractive effort in the mountains. 14" (356 mm) piston valves admitted steam to the cylinders and firebox heating surface area included that of the four Security arch tubes.

The H-8s were retired in 1953-1954.


Class H-9a (Locobase 411)

Data from "Consolidation Locomotives for the Western Maryland," Railway Age, Volume 70, No. 19 (13 May 1921), p. 1117-1120; and WM Miscellaneous Steam Locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 58, pp.399+. (Thanks to Chris Hohl for noting the as-built tender capacity.) Works numbers were 54411, 54493-54501 in January 1921; 54609-54613, 54660, 54686-54694 in March; 54714-54717, 54732-54739 in April; 54750-54752 in May; 56027-56028, 56112-56117 in January 1923; 56395-56396 in April.

The class was delivered with 262 sq ft (24.35 sq m) of firebox heating surface. Beginning in the 1930s, the WM added thermic syphons to the firebox, which resulted in the 333 sq ft (30.95 sq m) shown in the specifications. The 14" (356 mm) American semi-plug piston valves had a 7" (178 mm) travel and a 3/16" (4.75 mm) lead. (Note: this design used a snap-ring that expanded to fit the valve chamber when the throttle was closed. When steam was admitted between the seats, a set of wedges locked into a fixed diameter to provide a plug-like seal. One big advantage claimed was much better wear resistance.)

RA reported that the service for which this Consolidation was intended combined relatively light rail (90 lb), tight curves (22 deg maximum), and steep grades of up to 3 1/2%. RA outlines the reasons for going with a 2-8-0 instead of the more fashionable Mikado (2-8-2) then supplanting 2-8-0s on many railroads. In those services that required pulling power and low speed -- heavy drag -- the Consolidation's boiler capacity was adequate. The late cutoff of 88.3% indicates perhaps an unwonted lack of concern about running out of steam.

The first batch was delivered with tenders carrying 16 tons (14,515 kg) of coal in a long, low tank that was designed to keep the center of gravity as low as possible while accommodating a Duplex automatic stoker.. It weighed 270,000 lb (122,470 kg). Beginning with 841, the redesigned tender carried the 20 1/2 tons shown in the specifications.

Later in their careers, the tender carried 23 tons (20.9 tonnes) of coal as shown in the specification above.

Moreover, the lack of a trailing truck meant less maintenance and, "the non-symmetrical wheel-base [wa]s easier on the track." In sum, said RA, "Such a locomotive, with a high percentage of total weight on driving wheels, is well fitted for heavy, slow speed service."

O. S. Nock (RWC IV, plate 169) calls these engines "one of the highest developments of the 2-8-0 type anywhere in the world." He notes that east of Cumberland, Md on the Baltimore-McConnellsville main line, the average revenue tonnage for these engines reached 657 tons (597 metric tons). Maximum train loads reached 7,000 tons.

The Reading's I10 was based on these Western Maryland locomotives; see Locobase 414.

Principal Dimensions by Steve Llanso of Middle Run Media
Class27/H-330 / H-3f37 / H-3g45 / H-3a / H-3b58/H-3b
Locobase ID12019 8872 12385 12001 12243
RailroadWest Virginia Central & Pittsburgh (WM)West Virginia Central & Pittsburgh (WM)West Virginia Central & Pittsburgh (WM)Western Maryland (WM)Western Maryland (WM)
CountryUSAUSAUSAUSAUSA
Whyte2-8-02-8-02-8-02-8-02-8-0
Number in Class161110
Road Numbers27/30130-34 / 351-35637 / 35745/34958-67/317-326
GaugeStdStdStdStdStd
Number Built161110
BuilderBurnham, Williams & CoBurnham, Williams & CoBurnham, Williams & CoBurnham, Williams & CoBurnham, Williams & Co
Year18921895190018911897
Valve GearStephensonStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)14 / 4.2714.25 / 4.3414.2514 / 4.2714 / 4.27
Engine Wheelbase (ft / m)21.50 / 6.5522.33 / 6.8122.3321.75 / 6.6321.50 / 6.55
Ratio of driving wheelbase to overall engine wheelbase 0.65 0.64 0.64 0.64 0.65
Overall Wheelbase (engine & tender) (ft / m)51.68 / 15.75
Axle Loading (Maximum Weight per Axle) (lbs / kg)33,100 / 15,014
Weight on Drivers (lbs / kg)125,000 / 56,699125,000108,000 / 48,988 / 55,338
Engine Weight (lbs / kg)120,000 / 54,431140,000 / 63,503140,000122,000 / 55,338 / 67,495
Tender Loaded Weight (lbs / kg)91,600 / 41,549
Total Engine and Tender Weight (lbs / kg)231,600 / 105,052
Tender Water Capacity (gals / ML)3000 / 11.364000 / 15.1545003300 / 12.503300 / 12.50
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)9 / 8
Minimum weight of rail (calculated) (lb/yd / kg/m)52 / 2652 / 2645 / 22.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)50 / 127050 / 12705051 / 129550 / 1270
Boiler Pressure (psi / kPa)140 / 970175 / 1210170200 / 1380200 / 1380
High Pressure Cylinders (dia x stroke) (in / mm)20" x 24" / 508x61021" x 26" / 533x66021" x 26" / x13" x 26" / 330x66020" x 24" / 508x610
Low Pressure Cylinders (dia x stroke) (in / mm)21" x 26" / 533x660
Tractive Effort (lbs / kg)22,848 / 10363.6934,111 / 15472.5133,137 / 15030.7121,178 / 9606.1932,640 / 14805.27
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.66 3.77 5.10
Heating Ability
Tubes (number - dia) (in / mm)215 - 2.25" / 57236 - 2.25" / 57236 - 2.25" / 261 - 2" / 51192 - 2.25" / 57
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)13.33 / 4.0613.29 / 4.0513.3712.96 / 3.9513.08 / 3.99
Firebox Area (sq ft / m2)144 / 13.38159 / 14.78160139 / 12.92138 / 12.82
Grate Area (sq ft / m2)24 / 2.2333.10 / 3.0833.2029.50 / 2.7429.80 / 2.77
Evaporative Heating Surface (sq ft / m2)1819 / 169.052007 / 186.5220051897 / 176.301608 / 149.39
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1819 / 169.052007 / 186.5220051897 / 176.301608 / 149.39
Evaporative Heating Surface/Cylinder Volume208.36192.61192.42474.59184.19
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation33605793564459005960
Same as above plus superheater percentage33605793564459005960
Same as above but substitute firebox area for grate area20,16027,82527,20027,80027,600
Power L133933922381442284387
Power MT276.69269.07345.23

Principal Dimensions by Steve Llanso of Middle Run Media
ClassH-3-cH-3-cH-4-bH-4/H-4-aH-5
Locobase ID8871 16164 8875 8873 1408
RailroadWest Virginia Central & Pittsburgh (WM)West Virginia Central & Pittsburgh (WM)West Virginia Central & Pittsburgh (WM)Western Maryland (WM)Western Maryland (WM)
CountryUSAUSAUSAUSAUSA
Whyte2-8-02-8-02-8-02-8-02-8-0
Number in Class2281618
Road Numbers347-34828-29/347-34838-41, 44-47/451-458101-116/401-416501-518
GaugeStdStdStdStdStd
Number Built2281618
BuilderWMBurnham, Williams & CoBurnham, Williams & CoBurnham, Williams & CoBurnham, Williams & Co
Year1892190019011905
Valve GearStephensonStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)14 / 4.2714 / 4.2714.25 / 4.3415.33 / 4.6714.25 / 4.34
Engine Wheelbase (ft / m)21.75 / 6.6321.75 / 6.6322.83 / 6.9623.67 / 7.2122.92 / 6.99
Ratio of driving wheelbase to overall engine wheelbase 0.64 0.64 0.62 0.65 0.62
Overall Wheelbase (engine & tender) (ft / m)49.67 / 15.1449.67 / 15.1452.90 / 16.1252.75 / 16.0852.75 / 16.08
Axle Loading (Maximum Weight per Axle) (lbs / kg)30,400 / 13,78945,900 / 20,82035,900 / 16,28442,100 / 19,096
Weight on Drivers (lbs / kg)118,100 / 53,569110,000 / 49,895157,800 / 71,577141,500 / 64,183163,500 / 74,162
Engine Weight (lbs / kg)129,600 / 58,786126,000 / 57,153173,900 / 78,880159,000 / 72,121182,700 / 82,871
Tender Loaded Weight (lbs / kg)88,400 / 40,098120,000 / 54,431114,400 / 51,891115,400 / 52,345
Total Engine and Tender Weight (lbs / kg)218,000 / 98,884293,900 / 133,311273,400 / 124,012298,100 / 135,216
Tender Water Capacity (gals / ML)4200 / 15.913000 / 11.368000 / 30.308000 / 30.306000 / 22.73
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)9 / 89 / 811 / 1012 / 1112 / 11
Minimum weight of rail (calculated) (lb/yd / kg/m)49 / 24.5046 / 2366 / 3359 / 29.5068 / 34
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)50 / 127050 / 127050 / 127056 / 142251 / 1295
Boiler Pressure (psi / kPa)170 / 1170180 / 1240190 / 1310180 / 1240200 / 1380
High Pressure Cylinders (dia x stroke) (in / mm)19" x 26" / 483x66015" x 26" / 381x66022" x 28" / 559x71122" x 28" / 559x71122" x 28" / 559x711
Low Pressure Cylinders (dia x stroke) (in / mm)22" x 26" / 559x660
Tractive Effort (lbs / kg)27,126 / 12304.1624,440 / 11085.8143,773 / 19855.1237,026 / 16794.7345,173 / 20490.15
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.35 4.50 3.60 3.82 3.62
Heating Ability
Tubes (number - dia) (in / mm)261 - 2" / 51261 - 2" / 51300 - 2.25" / 57247 - 2.25" / 57298 - 2.25" / 57
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)12.87 / 3.9212.87 / 3.9213.83 / 4.2214.50 / 4.4213.83 / 4.22
Firebox Area (sq ft / m2)143 / 13.29139 / 12.91200 / 16.17191 / 17.74200 / 18.58
Grate Area (sq ft / m2)29 / 2.6929 / 2.6937.30 / 3.4735.60 / 3.3137.20 / 3.46
Evaporative Heating Surface (sq ft / m2)1902 / 176.701897 / 176.242604 / 242.012285 / 212.282614 / 242.85
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1902 / 176.701897 / 176.242604 / 242.012285 / 212.282614 / 242.85
Evaporative Heating Surface/Cylinder Volume222.98356.52211.36185.47212.18
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation49305220708764087440
Same as above plus superheater percentage49305220708764087440
Same as above but substitute firebox area for grate area24,31025,02038,00034,38040,000
Power L143463399463244184987
Power MT324.51272.49258.85275.34268.98

Principal Dimensions by Steve Llanso of Middle Run Media
ClassH-6H-6AH-7H-7aH-7a/b - superheated syphons
Locobase ID1409 8320 1410 1411 8887
RailroadWestern Maryland (WM)Western Maryland (WM)Western Maryland (WM)Western Maryland (WM)Western Maryland (WM)
CountryUSAUSAUSAUSAUSA
Whyte2-8-02-8-02-8-02-8-02-8-0
Number in Class30463010
Road Numbers601-630621, 625, 627, 630701-706707-736752, 754, 756+
GaugeStdStdStdStdStd
Number Built30630
BuilderBurnham, Williams & CoWMBaldwinAlco-RichmondWM
Year1906192619101911
Valve GearWalschaertWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.33 / 4.6715.33 / 4.6716 / 4.8816.67 / 5.0816.67 / 5.08
Engine Wheelbase (ft / m)24 / 7.3224 / 7.3225 / 7.6225.67 / 7.8226.17 / 7.98
Ratio of driving wheelbase to overall engine wheelbase 0.64 0.64 0.64 0.65 0.64
Overall Wheelbase (engine & tender) (ft / m)58.42 / 17.8158.42 / 17.8166.58 / 20.2968.58 / 20.90
Axle Loading (Maximum Weight per Axle) (lbs / kg)47,250 / 21,43247,250 / 21,43261,000 / 27,66962,200 / 28,213
Weight on Drivers (lbs / kg)182,000 / 82,554182,000 / 82,554202,000 / 91,626215,000 / 97,522216,000 / 97,976
Engine Weight (lbs / kg)200,000 / 90,719200,000 / 90,719222,000 / 100,698241,000 / 109,316243,000 / 110,223
Tender Loaded Weight (lbs / kg)136,600 / 61,961136,600 / 61,961172,500 / 78,245174,200 / 79,016175,200 / 79,469
Total Engine and Tender Weight (lbs / kg)336,600 / 152,680336,600 / 152,680394,500 / 178,943415,200 / 188,332418,200 / 189,692
Tender Water Capacity (gals / ML)7000 / 26.527000 / 26.529500 / 35.989500 / 35.989500 / 35.98
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)12 / 1112 / 1114 / 1314 / 1314 / 13
Minimum weight of rail (calculated) (lb/yd / kg/m)76 / 3876 / 3884 / 4290 / 4590 / 45
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)57 / 144857 / 144860 / 152460 / 152460 / 1524
Boiler Pressure (psi / kPa)200 / 1380200 / 1380200 / 1380200 / 1380200 / 1380
High Pressure Cylinders (dia x stroke) (in / mm)22" x 30" / 559x76222" x 30" / 559x76224" x 30" / 610x76225" x 30" / 635x76224" x 30" / 610x762
Tractive Effort (lbs / kg)43,305 / 19642.8443,305 / 19642.8448,960 / 22207.9153,125 / 24097.1248,960 / 22207.91
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.20 4.20 4.13 4.05 4.41
Heating Ability
Tubes (number - dia) (in / mm)344 - 2.25" / 57323 - 2.25" / 57338 - 2.25" / 57239 - 2.25" / 57239 - 2.25" / 57
Flues (number - dia) (in / mm)36 - 5.5" / 14036 - 5.5" / 140
Flue/Tube length (ft / m)14.75 / 4.5014.92 / 4.5516 / 4.8815.91 / 4.8515.91 / 4.85
Firebox Area (sq ft / m2)174 / 16.16227 / 21.10187 / 17.37221 / 20.54297 / 27.60
Grate Area (sq ft / m2)52.50 / 4.8852.50 / 4.8854 / 5.0261.80 / 5.7461.80 / 5.74
Evaporative Heating Surface (sq ft / m2)3163 / 293.853033 / 281.883466 / 3223290 / 305.763227 / 299.91
Superheating Surface (sq ft / m2)658 / 61.15658 / 61.15
Combined Heating Surface (sq ft / m2)3163 / 293.853033 / 281.883466 / 3223948 / 366.913885 / 361.06
Evaporative Heating Surface/Cylinder Volume239.62229.77220.62193.08205.41
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,50010,50010,80012,36012,360
Same as above plus superheater percentage10,50010,50010,80014,46114,461
Same as above but substitute firebox area for grate area34,80045,40037,40051,71469,498
Power L158055999560312,10913,538
Power MT281.27290.67244.60496.66552.71

Principal Dimensions by Steve Llanso of Middle Run Media
ClassH-7bH-8H-9a
Locobase ID13937 1412 411
RailroadWestern Maryland (WM)Western Maryland (WM)Western Maryland (WM)
CountryUSAUSAUSA
Whyte2-8-02-8-02-8-0
Number in Class152050
Road Numbers750-764770-789801-850
GaugeStdStdStd
Number Built152050
BuilderAlco-RichmondAlco-SchenectadyBaldwin
Year191219141921
Valve GearWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)16.67 / 5.0816.67 / 5.0817.50 / 5.33
Engine Wheelbase (ft / m)25.67 / 7.8226.17 / 7.9827.25 / 8.31
Ratio of driving wheelbase to overall engine wheelbase 0.65 0.64 0.64
Overall Wheelbase (engine & tender) (ft / m)66.58 / 20.2968 / 20.7374.15 / 22.60
Axle Loading (Maximum Weight per Axle) (lbs / kg)58,700 / 26,62657,400 / 26,03673,900 / 33,521
Weight on Drivers (lbs / kg)216,000 / 97,976217,500 / 98,656287,010 / 130,186
Engine Weight (lbs / kg)243,000 / 110,223244,500 / 110,903309,910 / 140,573
Tender Loaded Weight (lbs / kg)174,200 / 79,016175,200 / 79,469285,600 / 129,546
Total Engine and Tender Weight (lbs / kg)417,200 / 189,239419,700 / 190,372595,510 / 270,119
Tender Water Capacity (gals / ML)9500 / 35.989500 / 35.9815,000 / 56.82
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)14 / 1314 / 1323 / 15
Minimum weight of rail (calculated) (lb/yd / kg/m)90 / 4591 / 45.50120 / 60
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)60 / 152451 / 129561 / 1549
Boiler Pressure (psi / kPa)200 / 1380200 / 1380210 / 1450
High Pressure Cylinders (dia x stroke) (in / mm)25" x 30" / 635x76225" x 30" / 635x76227" x 32" / 686x813
Tractive Effort (lbs / kg)53,125 / 24097.1262,500 / 28349.5668,263 / 30963.61
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.07 3.48 4.20
Heating Ability
Tubes (number - dia) (in / mm)225 - 2.25" / 57239 - 2.25" / 57240 - 2.25" / 57
Flues (number - dia) (in / mm)36 - 5.5" / 14036 - 5.5" / 14050 - 5.5" / 140
Flue/Tube length (ft / m)15.91 / 4.8515.25 / 4.6515.25 / 4.65
Firebox Area (sq ft / m2)221 / 20.53250 / 23.23333 / 30.94
Grate Area (sq ft / m2)61.80 / 5.7461.30 / 5.6974.90 / 6.96
Evaporative Heating Surface (sq ft / m2)3097 / 287.723169 / 294.413463 / 321.72
Superheating Surface (sq ft / m2)658 / 61.13625 / 58.06945 / 87.79
Combined Heating Surface (sq ft / m2)3755 / 348.853794 / 352.474408 / 409.51
Evaporative Heating Surface/Cylinder Volume181.75185.97163.27
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation12,36012,26015,729
Same as above plus superheater percentage14,58514,22219,032
Same as above but substitute firebox area for grate area52,15658,00084,615
Power L111,88310,02013,723
Power MT485.14406.26421.64

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