The Green Party has proposed that the Northern City Line be connected to the Waterloo & City line to create a new cross-London route.[citation*needed] The core section of the route would be from Finsbury Park to Clapham Junction via Moorgate, Bank and Waterloo, with a new connection at Blackfriars. Through services could then run from Welwyn Garden City and Hertford North to destinations like Hounslow, Richmond, Shepperton, Kingston and Weybridge, thus enabling much better use of the capacity offered by this part of the network, particularly outside city commuting hours.[3] However, the Waterloo & City was designed and built as a deep tube line; were this to be connected to the Northern City line this would mean either a reversion to using deep tube stock along the whole length (as when the NCL was part of the Northern line), or converting the Waterloo & City for main line sized rolling stock. The latter would be made more difficult still because of the tight curves, which would not suit conventional carriages. It would therefore probably mean boring completely new tunnels for much of the length.
