The long-term aim of the Great Western Society is to buy the freehold of Didcot Railway Centre, according to new chairman Richard Croucher.

Graham Perry, a founder of the Great Western Society, hands over the chairmanship to Richard Croucher, right, in front of the society's first engineThe railway preservation society now leases nearly 20 acres of sidings and buildings on the northern side of Didcot Parkway Station.

Mr Croucher said: "In order to secure the future of the society and its collection of restored Great Western Railway rolling stock, we need to acquire the freehold - or at least negotiate a 125-year lease. It will be our priority."

Also high on the GWS agenda is the development of centre sidings, leased from Railtrack this year. Plans include a new visitor and education centre, and improved access to the railway centre.

Mr Croucher, 56, has been a member of the society for 38 of its 40 years, including deputy chairman for the past 16 years.

At a 40th anniversary steam day, Mr Croucher posed for photographs - together with retiring chairman Graham Perry - with the first locomotive to be acquired by the society. The branch line engine, No 4866, was bought in 1967 and is typical of the class of engine that would have run on branch lines in Oxfordshire.

Founder member Mr Perry, 57, said No 4866 originally cost the society £700, plus a £50 delivery fee.

The society now owns 23 locomotives and 80 items of rolling stock - the largest collection of preserved steam locomotives from one railway company in the world.

Didcot Railway Centre draws an estimated 100,000 visitors annually, making it the third most popular tourist attraction in the county behind Blenheim Palace and Cotswold Wildlife Park.