Great Western Railway 2900Saint class
2981Ivanhoe atTilehurst in 1948
Type and origin Power type Steam Designer George Jackson Churchward Builder GWRSwindon Works Build date 1902-1913 Total produced 77
Specifications Configuration: ​  • Whyte 4-6-0 (thirteen examples were built as4-4-2 but rebuilt to 4-6-0 1912/13).  • UIC 2'Ch2 Gauge 4 ft 8+1⁄2 in (1,435 mm)standard gauge Leading dia. 3 ft 2 in (0.965 m) Driver dia. 6 ft8+1⁄2 in (2.045 m) Trailing dia. 4 ft1+1⁄2 in (1.257 m) (4-4-2 only) Wheelbase loco: 27 ft 1 in (8.26 m) – 27 ft 7 in (8.41 m) loco & tender: 53 ft4+3⁄4 in (16.28 m) – 53 ft10+3⁄4 in (16.43 m) Length 63 ft0+1⁄4 in (19.21 m) Width 8 ft 11 in (2.718 m) Height 13 ft3+1⁄2 in (4.051 m) Axle load 18long tons (18 t; 20short tons) Loco weight 68.30 long tons (69.40 t; 76.50 short tons) Tender weight 43.15 long tons (43.84 t; 48.33 short tons) Fuel capacity 5 long tons (5.1 t; 5.6 short tons) Water cap. 3,500 imp gal (16,000 L; 4,200 US gal) – 4,000 imp gal (18,000 L; 4,800 US gal) Firebox: ​  • Grate area 27.22 sq ft (2.529 m2) Boiler GWR Standard No. 1 (with variations) Boiler pressure 225 psi (1.55 MPa) (production series) Heating surface: ​  • Firebox 154.94 sq ft (14.394 m2)  • Tubes and flues 1,485.96 sq ft (138.050 m2) Superheater: ​  • Type "Swindon No. 3"  • Heating area 307.52 sq ft (28.570 m2) Cylinders Two, outside Cylinder size 18 in × 30 in (457 mm × 762 mm) or 18+1⁄2 in × 30 in (470 mm × 762 mm) Valve gear Stephenson Valve type 10 inches (254 mm) piston valves (2935 rebuilt with poppet valves)
Performance figures Tractive effort 20,530 lbf (91.32 kN) – 24,395 lbf (108.51 kN)
Career Operators Great Western Railway British Railways Class 2900 orSaint Power class GWR: C BR: 4P Number in class 76 Numbers 2900–2955, 2971-2990, 2998 Axle load class GWR: Red Retired 1924, 1931–1953 Disposition One rebuilt asHall class (2925/4900Saint Martin), remainderscrapped; One 4900 example has been backdated to 29XX specification

TheGreat Western Railway 2900 Class orSaint Class was built by theGreat Western Railway'sSwindon Works. The class incorporated several series of 2-cylindersteam locomotives designed byGeorge Jackson Churchward and built between 1902 and 1913 with differences in dimensions for comparative purposes. The majority of these were built as4-6-0 locomotives; but thirteen examples were built as4-4-2 locomotives and later converted to 4-6-0 during 1912/13. They proved to be a highly successful class which established the design principles for GWR 2-cylinder classes over the next fifty years, and influenced similar classes on other British railways.

After finally converting the last broad gauge lines in 1892, theGreat Western Railway (GWR) began a period of modernisation as new cut-off lines shortened its routes to west of England, South Wales and Birmingham. During the first decade of the twentieth century theChief Mechanical Engineer,George Jackson Churchward, designed or acquired a number of experimental locomotives with different wheel arrangements and boiler designs to help him plan for the future motive power needs of the railway.^[1] The first of these was a two-cylinder 4-6-0 locomotive, designed in 1901 whilst Churchward was still the Chief Assistant of his predecessorWilliam Dean.

Between 1902 and 1905 Churchward built and tested three prototype locomotives with detail differences, before using the third as the basis for the production series.

The first prototype was completed at theSwindon Works of the GWR (Lot 132) in February 1902.^[2] It was numbered 100 and in June 1902 was namedDean (laterWilliam Dean) to mark the latter's retirement. The new design incorporated all of Churchward's current ideas including a domelessparallel boiler, raisedBelpaire firebox, 19 in (48.3 cm) diameter outside cylinders with 30 in (76.2 cm) piston stroke, and boiler pressure of 200 psi (1.38 MPa).^[3] The piston valves were driven by rocking levers actuated by the expansion link ofStephenson valve gear – this particular design was only used on No. 100.^[4] The parallel boiler was later replaced with ataper boiler, and then the firstsuperheated taper boiler in 1910.

Churchward had studied American boiler design, but he was also later influenced bycontinental practice in efficient motion design. Ade Glehn4-4-2 compound engine was ordered from theSociété Alsacienne de Constructions Mécaniques (SACM) for comparative trials on the GWR.^[5] According to E.C. Poultney, No. 100 was the first 4-6-0 locomotive to have high enough boiler capacity and steam ports large enough to handle the steam flow required by large cylinders: "The engine probably influenced to a large extent the use made of engines of the 4-6-0 type".^[6] No.100 was renumbered 2900 in 1912, and was withdrawn from service in 1932.

A second prototype locomotive, No. 98, was built at Swindon Works in March 1903 (Lot 138) to a similar design but with a taper boiler, re-designed valve gear layout and cylinders and a shorter wheelbase.^[7] Valve diameters were increased from6+1⁄2 inches (170 mm) to 10 inches (250 mm).^[5] According to Poultney, these improvements "may truly be said to be the keystone of the arch upon which all modern locomotives are designed".^[8] In 1906 this locomotive was re-boilered with a 225 psi (1.55 MPa) boiler to correspond with the third prototype. This prototype locomotive was namedVanguard in 1907 (renamedErnest Cunard in the same year). It was renumbered 2998 in 1912, received asuperheated boiler in 1911 and was withdrawn in 1933.

A third prototype, No. 171, was built at Swindon in December 1903 (Lot 145) incorporating the improvements to No. 98 but with a 225 psi (1.55 MPa) boiler and minor amendments to the heating surface and grate area. It was built as a 4-6-0 but in October 1904 it was converted to a 4-4-2 to enable better comparison with the performance of the French built de Glehn 4-4-2 Compound; it was reconverted to 4-6-0 in July 1907.^[7] The conversion was carried out by substituting4 ft1+1⁄2 in (1.257 m) trailing wheels with outside suspension for the final set of driving wheels. It was namedAlbion in 1904, renumbered 2971 in 1912, received asuperheated boiler in 1910 and was withdrawn in 1946. No. 171 formed the basis of the main production series, introduced in 1905, although at this time Churchward was still unsure of the relative merits of the 4-4-2 and 4-6-0 wheel arrangements.

The Saint class appeared in four production series built between 1905 and 1913, each of which differed in dimensions. There were also differences between members of each series in terms of the boilers used, wheel arrangement, and arrangements for superheating. Different series and individual locomotives within series were also fitted with different tenders ranging from 3,500 imp gal (16,000 L; 4,200 US gal) to 4,000 imp gal (18,000 L; 4,800 US gal) capacity.

Whilst 171 was undergoing trials in 1905 nine further locomotives were ordered to be built at Swindon Works to a similar design (Lot 154) followed by a further ten (Lot 158), totalling 19 locomotives in this series. Thirteen of these were built as 4-4-2s and six as 4-6-0s. However, by January 1913, Churchward was persuaded by the superior adhesion provided by a 4-6-0 and they had all been converted to this wheel arrangement.^[9] The new locomotives were numbered 172–190 (renumbered 2972–2990 in 1912). Twelve of the series were named after characters in the novels ofSir Walter Scott. Directors of the GWR accounted for most of the other names. The series was withdrawn between 1931 and 1951.

A second series of ten similar locomotives appeared in May 1906 (Swindon Lot 164), numbered 2901–10 and named after historical, mythological or poetical 'Ladies'. Nos. 2904–6 had short tapered boilers and shortsmokeboxes, whereas Nos. 2902–03 and 2907–10 had longer versions. All except 2901 had 18.125 in × 30 in (460 mm × 762 mm) cylinders, giving a tractive effort of 23,382 lbf (104.01 kN). No. 2901Lady Superior was the first British locomotive to be built with a modernSchmidtsuperheater.^[7] The remainder of the locomotives were fitted with Swindon No.3 superheaters between 1909 and 1911 and were withdrawn between 1933 and 1952.

In May 1906Charles Collett, then assistant manager of Swindon Works, supervised a demonstration run of number 2903Lady of Lyons, newly released from the erecting shop. By mile-post timings observed from the engine and from passing times recorded atLittle Somerford andHullavington signal boxes,4+1⁄2 miles apart and with a descending gradient of 1 in 300 between them, a speed of approximately 120 miles per hour (190 km/h) was recorded, but this is not reliable enough to be considered a record.^{[10][11][12][13]}

A third series of twenty further locomotives appeared during August and September 1907 (Swindon Lot 170), numbered 2911–30 and named after Saints. The framing for these had long curved ends under the cab and over the cylinders, which greatly improved the rather angular appearance of the earlier locomotives. They were fitted with cone boilers and smokeboxes. In October 1908, No. 2922Saint Gabriel was fitted with a Swindon No. 2 superheater. The following year the Swindon No. 3 superheater became standard for the class.^[14] Between 1909 and 1912 the remainder of the locomotives were fitted with the Swindon No. 3 superheater. TheSaints were withdrawn between 1932 and 1951. No. 2925Saint Martin was rebuilt with smaller wheels in December 1924 to become the prototypeCollett 4900 and renumbered 4900 but still carrying the same name.

A fourth series of 25 locomotives appeared during the years 1911 to 1913 (Swindon Lots 185, 189 and 192). These were numbered 2931–55 and named after famous Courts (i.e. mansions). They were all built with superheaters and there were detailed differences between the boilers used on different lots.^[14] They were all withdrawn between 1948 and 1953.

The locomotives performed well as passenger locomotives over all the long-distance routes of the GWR and on all but the fastest express trains until they gradually became displaced to secondary services by theCastle Class in the late 1920s and 1930s.^[16][17] However, the6 ft8+1⁄2 in (2.045 m) driving wheels limited their usefulness on freight trains. Churchward had recognized this limitation by the introduction of hisGWR 4700 Class2-8-0 design with 5 ft 8 in (1.727 m) driving wheels in 1919, intended for express goods trains. However, Churchward's successorCharles Collett felt that a smaller-wheeled version of the 'Saint' class could form the basis of a successfulmixed-traffic class of locomotives. He therefore rebuilt No. 2925Saint Martin with 6 ft (1.829 m) driving wheels to become the prototype of his successfulHall Class locomotives. Thus the 2900 class became a template for later GWR 2-cylinder 4-6-0 classes including theModified Hall,Grange,Manor andCounty classes, all of which were of the same basic design.^[18] Moreover they also influenced similar engines on other railways such as theLMS "Black Fives", theLNER B1s and theBR Standard Class 5s.^[19]

Collett also experimented on several other members of the class. In 1923 No. 2933 was given an alteredblastpipe and in 1927 No. 2947 was fitted with cylinder by-pass valves. In 1931 No. 2935 was rebuilt withLentz-stylerotary cam poppet valve gear,^[20] which remained in use until the engine was scrapped in 1948.^[21]

The class incorporated many revolutionary advances which were influential in British locomotive design for the next fifty years. According to The Great Western Society, 'Saint' class locomotives "represented one of the most important steps forward in railway traction of the 20th century", and they "are now acknowledged to have had a profound influence on almost every aspect of subsequent steam locomotive development".^[22] W.A. Tuplin commented; "No other locomotive design, except perhaps Stephenson's 'Rocket', has represented such a long leap in the right direction as GWR No. 98.".^[19]

• On 6 January 1932, locomotive No. 2949Stanford Court was hauling a milk train that overran signals at Didcot East Junction and collided with a freight train, which was being hauled byGWR 2800 Class2-8-0 No. 2808. The locomotive was derailed and six wagons were slightly damaged.^[23]

The below list shows when all of the original 2900's were withdrawn from service.

None of the original Saints survived into preservation, so theGreat Western Society purchasedGWR 4900 Hall Class 4-6-0 No. 4942Maindy Hall fromBarry Scrapyard in 1974, with the intention to rebuild it as a Saint. This would reverse the procedure whereby a Saint was rebuilt as the Hall prototype. The project finally began in earnest in 1995, by which time engineering capability in the preservation movement had greatly increased. It was decided that the engine would be built in the original straight frame form like the first Saints instead of the later curved frame style as fitted to Maindy Hall.^[28] Following thirty years of storage and fifteen years of rebuilding work,2999Lady of Legend made its first moves in April 2019 and was formally launched at theDidcot Railway Centre in the same month.^[29]

• List of GWR standard classes with two outside cylinders

Wikimedia Commons has media related toGWR 2900 Class.

• Great Western Society "Great Western Archive", details of locomotives:2900 - 2924,  2925 - 2955,  2971 - 2998

• Great Western Railway locomotives
• 4-6-0 locomotives
• Railway locomotives introduced in 1902
• Scrapped locomotives
• Standard-gauge steam locomotives of Great Britain
• 2′C h2 locomotives
• 2′B1 h2 locomotives
• Passenger locomotives in the United Kingdom

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