Great Western 4-2-2 Locomotives in Great_Britain


Class Details by Steve Llanso of Sweat House Media

Class 3001 (Locobase 3028)

Data from Ahrons (1927) and C J Bowen Cooke, "British Locomotives", (London: Whitaker & Co, 1894)

One of the last of the "singles" for any railroad, and one of the last convertible locomotives delivered to the GW. The first 8 were convertible, the latter were delivered as standard-gauge engines. After a derailment descending the 1% grade at the Box Tunnel, all thirty engines were rebuilt as 4-2-2s. See Locobase 2244.


Class Alma (Locobase 10223)

Data from "The BG Locomotives of the Great Western Ry", The Locomotive Magazine, Vol VII (May 1902), p. 91.

The Iron Duke/Courier engines (Locobases 2572 and 2924) having proved quite successful as express engines of considerable power and size, the GWR ordered 7 more. Rothwell delivered these seven engines, all named for battles or sites in the Crimean War, over a nine-month span:

Alma November 1854

Balaclava December 1854

Inkerman March 1855

Kertch April 1855

Crimea May 1855

Eupatoria May 1855

Sebastopol July 1855

Like the earlier batches, engines in this class racked up some impressive mileage, 4 of them exceeding 600,000 miles before being replaced and one, Sebastapol, accumulating 707,148 miles before being scrapped in 1880 in favor of a new engine with the same name.


Class Bulkeley (Locobase 8444)

Data from J. Pearson Pattison, British Railways: Their Passenger Services, ... (London: Cassell & Co, 1893), p 96 and from"The BG Locomotives of the Great Western Ry", The Locomotive Magazine, Vol VII (December 1902), p. 194.

This was the second batch of replacement locomotives produced by William Dean to make up the deficit caused by the retirement of many 1st-generation single-drivered engines. These had a slightly bigger boiler than the 1878 batch shown in Locobase 10242.


Class Courier (Locobase 2924)

Heating surface data from Ahrons (1927) and other information from "The BG Locomotives of the Great Western Ry", The Locomotive Magazine, Vol VI (December 1901), p.200-201.

The second class of follow-ons to the Great Western, these engines had shorter tubes than the Iron Dukes and a longer firebox. After 16 were supplied in 1848, Rothwell & Co. added 7 in 1854-1855 (See Locobase 10223).

Some of the 16 in this class ran up amazing amounts of revenue miles. Courier accumulated 746,210 miles before scrapping in 1878. Tartar's first boiler took it 731,817 miles by 1876 and, after refitting with a new boiler, the locomotive continued in service until the Broad Gauge was narrowed in 1892. The champion seems to have been Lord of the Isles, which after a stint on display at the 1851 Exhibition in the Crystal Palace, entered service in July 1852 and traveled 789,300 miles over the next 29 years.


Class Dean Single/Achilles (Locobase 2244)

Data from Ahrons (1927); and "3001 'Dean Single' class introduction", on John Daniel's Great Western Archive website at [], last accessed 15 August 2023. See also Clement Edwin Stretton, The Locomotive Engine and its Development (London: Crosby Lockwood and Son, 1903), pp. 177-178.

These class of William Dean-designed engines included 30 3001-class 2-2-2s (Locobase 9062) that proved prone to derailment, including the Wigmore Castle's accident inside the Box Tunnel. In were rebuilt as bogie singles from March to December 1894. (3021-3028--in service in 1891-- had also been regauged from the 7' broad gauge to standard gauge--the other 22 were delivered as standard-gauge locomotives in 1892.).

3031appeared in 1894 as the lead engine of the Achilles class. The new bogie single layout propelled the next 50 locomotives as built. Because the entire class of 80 engines were built to the same design, they often were called the "Dean Singles". Clement Stretton reported in 1895 that they were "giving very satisfactory results upon the heaviest and fastest main line trains between London, Bristol and Newton Abbot." Coal consumption, he wrote, had been found "to be between 31 and 33 lb per mile [8.73-9.30 kg/km)] with these trains."

But as John Daniel wrote, by the turn of the century, the single-driver engine simply couldn't keep pace with the heavier trains needed to satisfy increased demand. John Daniel noted that George Churchward tinkered with boiler and firebox designs on most Great Western locomotives at the time. Beginning in March 1901, 3027 received a Standard #2 boiler and drumhead smokebox; its 5" (127 mm) increase in boiler diameter raised the centerline as high as Churchward dared..1901 saw the re refitting of the Nelson (3048) with a Belpaire firebox behind a domeless boiler. Kennet underwent a similar change in 1902. Both later used a 180 psi setting These two engines later gave up their boilers.

Instead, in 1909 Churchward installed a round-topped boiler pressed to 180 psi, but he had not given up on the Belpaire firebox (of which he was quite fond). Ultimately 34 had the square-shoulder firebox fitted to the original boiler.

Doomed to obsolescence and not amenable to the kind of alterations conversion to a 4-4-0 might require, Churchward sent the entire class to the scrapper between 1908 and 1915.


Class Great Western (Locobase 10243)

Data from J. Pearson Pattison, British Railways: Their Passenger Services, ... (London: Cassell & Co, 1893), p 96 and from"The BG Locomotives of the Great Western Ry", The Locomotive Magazine, Vol VII (December 1902), p. 194.

The last of the Dean 4-2-2 restocking effort, this trio closed out broad-gauge express-engine production. Indeed the GWR regauging to standard dimensions would occur just four years later. Notice that the boiler had grown still larger than those on the Bulkeleys of 1880 (Locobase 8444).


Class Iron Duke (Locobase 2572)

Data from "Broad Gauge Express Passenger Engine 'Lord of the Isles', Great Western Railway", Railway Engineer, Volume 13, No 1 (January 1892), pp. 29-30. But see below for discussion of sources.

Immediate follow-on to the Great Western, this 4-2-2 replaced the gothic firebox of the former with a raised one that followed the boiler's profile.

Note on heating surface areas: Locobase used the data from the 1892 valedictory article for this long-lived class primarily because table included a direct comparison to the modernized locomotives shown in Locobase 2572.

According to a table reproduced in Gustav Reder (Michael Reynolds, trans), The World of Steam Locomotives (New York: Putnam, 1974), the class had 153 sq ft (14.21 sq m) of heating surface. Ahrons (1927), allowing the same number of 2" tubes, gives these dimensions: 1,647.4 sq ft of tubes, 142.8 in the firebox for 1,790.2 sq ft total. (Glover (1967) says 148 sq ft.) The table shows a distance between tube sheets of 11 ft 3 in, which would produce the heating surface shown in the specifications. On the other hand, the much more contemporaneous Bourne's Catechism of the Locomotive (4th ed published in 1856) gives 153 sq ft, 1,952 total heating surface for 305 tubes; G D Dempsey, CE & D Kinnear Clark, CE, A Rudimentary Treatise on the Locomotive Engine (London: Crosby, Lockwood & Co, 1879), p. 62 agreed. See long article in Locomotive Magazine, Vol VI (November 1901), p. 185-187.

Further information was published in the Scientific American Supplement, No. 458, October 11, 1884, which is reproduced by Project Gutenberg at ftp://sailor.gutenberg.lib.md.us/gutenberg/1/1/6/4/11647/11647-8.txt, accessed 25 January 2007. In addition to reproducing similar data, the account described the locomotives' consumption and performance:

"The average consumption of coal per mile, of thirteen of these engines, with the express trains between London and Bristol, during the half-year averaged 24.67 lb. per mile, the lowest being 23.22 lb., and the highest 26.17 lb., the average load being about eight coaches, or 243 tons ... [t]he fastest journey on record was performed at this time by one of these engines, when on May 14, 1848, the Great Britain took this Bristol express, consisting of four coaches and a van, to Didcot, fifty-three miles, in forty-seven minutes, or at the average speed of sixty-eight miles an hour. The maximum running speed was seventy-five miles an hour, and the indicated horse-power 1,000."

On 20 May 1892, 23 of the Great Western series --out of 30 original built in the 1850s and 15 built in the 1870s to replace 15 of the originals-- remained in revenue service


Class Lightning (Locobase 10242)

Data from J. Pearson Pattison, British Railways: Their Passenger Services, ... (London: Cassell & Co, 1893), p 96 and from"The BG Locomotives of the Great Western Ry", The Locomotive Magazine, Vol VII (December 1902), p. 194.

William Dean responded to the appearance of thinning ranks in GWR's aging express-singles stud by building new engines. His first six came out in 1878 and were quite similar to the earlier classes of 8-ft 4-2-2s, but had a longer wheelbase. The 1880 locomotives were similar, but slightly heavier and had different boilers; see Locobase 8444.


Class Rover (Locobase 2570)

Data from "Broad Gauge Express Passenger Engine 'Lord of the Isles', Great Western Railway", Railway Engineer, Volume 13, No 1 (January 1892), pp. 29-30. See also A H Malan, "New Narrow-Gauge Great Western Engines", English Illustrated Magazine (1893), pp. 199-203.

Later variant of the original 4-2-2. Locobase 2572 showed the original Great Western dimensions as given in the RE report cited above. That earlier entry also contains a summary of several other sources' data for heating surface areas, but explains that the RE entry's information provided a direct comparison between the original and the updated variants.

The first three were rebuilds of earlier Iron Dukes in 1870, followed by a run of new locomotives that were delivered between August of 1871 and July 1888. Each new locomotive adopted the name of an earlier single that had been retired.

These completed the run of 4-2-2s built to a single basic design over a 40-year period.

On 20 May 1892, 23 of the Great Western series --out of 30 original built in the 1850s and 15 built in the 1870s to replace 15 of the originals-- remained in revenue service

Principal Dimensions by Steve Llanso of Sweat House Media

Class3001AlmaBulkeleyCourierDean Single/Achilles
Locobase ID3028 10223 8444 2924 2244
RailroadGreat WesternGreat WesternGreat WesternGreat WesternGreat Western
CountryGreat BritainGreat BritainGreat BritainGreat BritainGreat Britain
Whyte4-2-24-2-24-2-24-2-24-2-2
Number in Class38761680
Road Numbers30013021-3030, 3001-2020, 3031-3080
GaugeStd7'7'StdStd
Number Built38761650
BuilderRothwell, Hick & RothwellGWR - SwindonGWRGWR - Swindon
Year18911854188018481891
Valve GearStephensonGoochGoochGoochStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 7.58 / 2.319 / 2.74
Engine Wheelbase (ft / m)18.50 / 5.6418.87 / 5.7518.7123.50 / 7.16
Ratio of driving wheelbase to overall engine wheelbase 0.40 0.38
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)43,560 / 19,75927,664 / 12,54835,840 / 16,25731,36040,320 / 18,289
Weight on Drivers (lbs / kg)43,560 / 19,75952,192 / 23,67435,840 / 16,25727,552 / 12,49740,320 / 18,289
Engine Weight (lbs / kg)99,008 / 44,90988,032 / 39,93193,408 / 42,36979,520 / 36,070109,760 / 49,786
Tender Loaded Weight (lbs / kg)71,680 / 32,51467,200 / 30,48172,800 / 33,022
Total Engine and Tender Weight (lbs / kg)170,688 / 77,423160,608 / 72,850182,560 / 82,808
Tender Water Capacity (gals / ML)3600 / 13.643600 / 13.644320 / 16.36
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.80 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)73 / 36.5087 / 43.5060 / 3046 / 2367 / 33.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)92.50 / 235084 / 213496 / 243896 / 243892.50 / 2350
Boiler Pressure (psi / kPa)160 / 11120 / 8.30150 / 10.30115 / 7.90160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)20" x 24" / 508x61018" x 24" / 457x61018" x 24" / 457x61018" x 24" / 457x61019" x 24" / 483x610
Tractive Effort (lbs / kg)14,115 / 6402.469442 / 4282.8210,328 / 4684.717918 / 3591.5512,738 / 5777.87
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.09 5.53 3.47 3.48 3.17
Heating Ability
Tubes (number - dia) (in / mm)245 - 1.75" / 44303 - 2" / 51330 - 1.625" / 41303 - 2" / 51266 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)11.7710.81 / 3.2911.3310.15 / 3.0911.75 / 3.58
Firebox Area (sq ft / m2)123.88 / 11.51171.20 / 15.90153 / 14.22162 / 15.06127 / 11.80
Grate Area (sq ft / m2)20.80 / 1.9325.50 / 2.3724 / 2.2325.50 / 2.3720.80 / 1.93
Evaporative Heating Surface (sq ft / m2)1467 / 136.341883 / 174.931751 / 162.731919 / 178.351561 / 145.02
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1467 / 136.341883 / 174.931751 / 162.731919 / 178.351561 / 145.02
Evaporative Heating Surface/Cylinder Volume168.11266.39247.72271.48198.20
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation33283060360029333328
Same as above plus superheater percentage33283060360029333328
Same as above but substitute firebox area for grate area19,82120,54422,95018,63020,320
Power L158976510854371046878
Power MT298.45274.99525.50568.44376.08

Principal Dimensions by Steve Llanso of Sweat House Media

ClassGreat WesternIron DukeLightningRover
Locobase ID10243 2572 10242 2570
RailroadGreat WesternGreat WesternGreat WesternGreat Western
CountryGreat BritainGreat BritainGreat BritainGreat Britain
Whyte4-2-24-2-24-2-24-2-2
Number in Class36623
Road Numbers
Gauge7'7'7'7'
Number Built36620
BuilderGWR - SwindonGWRGWR - SwindonGWR
Year1888184718781871
Valve GearGoochGoochGoochGooch
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)19 / 5.7918.66 / 5.6919 / 5.7918 / 5.49
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)47.50 / 14.48
Axle Loading (Maximum Weight per Axle) (lbs / kg)31,360 / 14,22535,840 / 16,25736,840 / 16,710
Weight on Drivers (lbs / kg)31,360 / 14,22535,840 / 16,25735,840 / 16,257
Engine Weight (lbs / kg)85,568 / 38,81392,376 / 41,90193,408 / 42,369
Tender Loaded Weight (lbs / kg)67,200 / 30,48142,560 / 19,30557,120 / 25,909
Total Engine and Tender Weight (lbs / kg)128,128 / 58,118149,496 / 67,810
Tender Water Capacity (gals / ML)3600 / 13.642160 / 8.183240 / 12.273600 / 13.64
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)52 / 2660 / 3060 / 30
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)96 / 243896 / 243896 / 243896 / 2438
Boiler Pressure (psi / kPa)150 / 10.30120 / 8.30140 / 9.70140 / 9.70
High Pressure Cylinders (dia x stroke) (in / mm)18" x 24" / 457x61018" x 24" / 457x61018" x 24" / 457x61018" x 24" / 457x610
Tractive Effort (lbs / kg)10,328 / 4684.718262 / 3747.589639 / 4372.189639 / 4372.18
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.80 3.72 3.72
Heating Ability
Tubes (number - dia) (in / mm)375 - 1.75" / 44300 - 2" / 51332 - 1.625" / 41375 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)11.3311.08 / 3.3811.3311.35 / 3.46
Firebox Area (sq ft / m2)137 / 12.73156 / 14.49131.80 / 12.25137 / 12.73
Grate Area (sq ft / m2)24 / 2.2325.46 / 2.3724 / 2.23
Evaporative Heating Surface (sq ft / m2)2085 / 193.771767 / 164.161728 / 160.592085 / 193.70
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)2085 / 193.771767 / 164.161728 / 160.592085 / 193.70
Evaporative Heating Surface/Cylinder Volume294.97249.98244.46294.97
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation360030553360
Same as above plus superheater percentage360030553360
Same as above but substitute firebox area for grate area20,55018,72018,45219,180
Power L19405691875648778
Power MT486.34465.28539.96

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