In April 1988, London Underground offered a total of 28 carriages in revenue-earning condition to NSE, joined by three further carriages in May 1989. In addition, between May 1988 and October 1990, four scrap vehicles and nine works vehicles, to be used for spare parts, were taken from LU's Ruislip depot. While the project's feasibility study suggested that three-car units would be preferred, it was thought that the alterations required to Ryde depot would be both difficult and expensive. It was instead decided that two-car units would be used, using a maximum of six coaches in any train formation. Of the 31 coaches available, 20 were selected for use on the island. These were extensively refurbished between 1989 and 1992 by Eastleigh Works to ready them for service on the line.