'Calbourne' was the first engine acquired by the embryonic Steam Railway in 1967 and the last survivor of a class that once numbered sixty strong. Originally constructed in 1891 at the Nine Elms locomotive works of the London and South Western Railway to a design by William Adams, Chief Mechanical Engineer. Her early years were spent based at Fratton and then Exeter, passing into the ownership of the Southern Railway in 1923. On 26 April 1925 she was shipped to the Isle of Wight as part of a major modernisation of the Island's railways. Various modifications were carried out including the fitting of Westinghouse air brake equipment and an extended coal bunker to increase her operational range.
The O2 class proved ideal for the Island's railways and a total of 23 were eventually shipped to the Island. By the end of 1960 they were the only class of steam engine operating on the Island's rail network.
Following the closures of the fifties and sixties the Island's remaining railway from Ryde Pier Head to Shanklin was electrified in early 1967 and 'Calbourne' was retained for engineers works trains before sale to the Wight Locomotive Society, the founding group of the present Isle of Wight Steam Railway. During the 1990s she was restored to early 1930s condition, wearing Southern Railway olive green livery and carrying an unmodified coal bunker.
'Calbourne' was withdrawn from service for overhaul on 9th August 2002. The extensive repairs were supported by a Heritage Lottery Fund grant and included a major boiler and firebox overhaul, a new smokebox, refitting the bunker extension and a repaint in early British Railways lined black livery. The overhaul was completed during the summer of 2010.