LSWR T3 class
T3 class 4-4-0 No. 563 on display at the Shildon Locomotion Museum.
Type and origin Power type Steam Designer William Adams Builder LSWR Nine Elms Works Build date 1892–1893 Total produced 20
Specifications Configuration: ​  • Whyte 4-4-0  • UIC 2'Bn Gauge 4 ft 8+1⁄2 in (1,435 mm) Leading dia. 3 ft 7 in (1.092 m) Driver dia. 6 ft 7 in (2.007 m) Length 54 ft 2+3⁄8 in (16.52 m) Height 13 ft 2+3⁄4 in (4.03 m) Axle load 15.725 long tons (16.0 t) Adhesive weight 35.525 long tons (36.1 t) Loco weight 48.55 long tons (49.3 t) Tender weight 36.2 long tons (36.8 t) Fuel type Coal Fuel capacity 3.00 long tons (3.05 t) Water cap. 3,300 imp gal (15,000 L; 4,000 US gal) Boiler pressure 175 psi (1.21 MPa) Cylinders Two, outside Cylinder size 19 in × 26 in (483 mm × 660 mm)
Performance figures Tractive effort 17,673 lbf (78.6 kN)
Career Operators LSWR · SR Class T3 Power class SR: I Withdrawn 1930-1936, 1943–1945 Disposition One preserved, remainder scrapped

The LSWR T3 class is a class of express passenger 4-4-0 steam locomotives designed for the London and South Western Railway by William Adams. Twenty were constructed between 1892 and 1893. One, No. 563, has been preserved and restored to full working order.

The class were numbered 557–576, and had been intended as a variant of the X2 class with slightly smaller driving wheels (6 ft 7 in or 2.007 m versus 7 ft 1 in or 2.159 m). In reality, the coupled wheelbase was lengthened by 6 inches (150 mm) and the locomotive was fitted with a deep firebox 6 feet 10 inches (2.08 m) long – the largest firebox of any of Adams' designs - with a 19¾ square foot grate area.^[1]

All passed to the Southern Railway at the grouping in 1923. Withdrawals started in 1930, and by the end of 1933 only three remained. No. 557 went in 1936, 571 in 1943, and the last, 563 was retired in August 1945 and set aside for preservation, at which point it had run 1.5 million miles.^[2] From May to October 2011 it was in Toronto, Ontario, on loan for use in a theatrical production of The Railway Children at Roundhouse Park, a role it reprised from December 2014 to January 2017 when the production was staged at King's Cross, London.^[3][4]

On 30 March 2017, No. 563 was transferred to the Swanage Railway Trust. The locomotive has now moved permanently to the Swanage Railway with a formal handover ceremony held at Corfe Castle on Saturday 27 May. Following an individual donation, the Swanage Railway declared their intention to explore the possibility of restoring the locomotive to working order, with a public appeal for additional funds being launched in October 2017.^[5] The evaluation was positive and a full restoration programme was begun, with a target of returning to operation in 2023.^[6] 563 returned to full public service on 8 October 2023 after a launch ceremony and supporters' special trains the previous day. ^{[7][8][9][10]}