4.2 Traction & rolling stock options

The rolling stock choices identified have enabled a comparison of:

  • 'Heavy rail' vehicles suitable for conventional segregated railway such as the existing Island Line;
  • 'Light rail' vehicles capable of street running; and
  • Diesel vehicles, which could avoid the need for electrification infrastructure.
Provision of ex London Underground tube stock is compared with new build vehicles both electric and diesel, and new light rail vehicles. Traction options for new build examined include 3rd rail electric DC, overhead electric DC, dual pick-up electric, diesel and 3rd rail DC electro/ diesel.

The feasibility, compatibility and life cycle cost issues have been examined. An important factor to note is that new build diesel vehicles would incur approximately double the whole life cost of cascaded ex LUL refurbished 3rd rail electric vehicles. Other key factors include the limited structure gauge through Ryde Tunnel, the implications of joint running over the IoW Steam Railway and of street running.