An occasional visitor to Glasgow, where she picks up stores, is the National Environmental Research Council's Research Ship DISCOVERY. Built at Aberdeen in 1962 at the long-closed Hall, Russell shipyard, DISCOVERY originally presented a completely different profile, as can be seen here. In 1991 she was given a major refit, which included lengthening to give her an overall length of 90.25 metres, and a corresponding gross tonnage of 3,008 tons. DISCOVERY operates worldwide, acting as a trials platform while undertaking marine biology and oceanographic research projects. Propulsion comes from a single screw driven by a diesel electric installation, and she can carry up to 28 scientists. She is due to be replaced by a new ship in 2011.