Thursday, March 23, 2006
By Tube from Edgware to Shanklin, IoW
The Department of Constitutional Affronts is currently giving serious consideration to an exciting proposal to extend the London Underground network and bring it within reach of a whole new group of potential customers.
The plan calls for a new route southwards from Morden, the Northern line's present southern terminus, with several intermediate stations en route - including access platforms for all four of the Solent's historic defensive sea-forts. Although some commentators have questioned the need for a new route through Hampshire, advocates point out that it will be underground and hence they will never know it's there except when they are in the basement and a train goes past.
The idea of linking the Isle of Wight (IoW)'s Island Line, which uses second-hand Northern Line underground stock for all its services, has been considered in the past. It was rejected on the grounds that fossilised dinosaur remains, which are particularly dense in the chalk marl of the Solent, would blunt the teeth of the Tunnel Boring Machines (TBMs). A new, more rational proposal abandons the central tenet of underground lines - their sub-surface nature - and instead relies on supporting the tube trains on a cusion of air as they cross the water. The trains would dive back under the comforting earth after making landfall to the east of the Portsmouth seafront.
The proposal has gained widespread support from transport advocates, who point out that the frequency of train services between Portsmouth and Ryde has dropped off sharply since the last train ferry left in the 1950s.
Based on their experience with the conventional Ryde-Portsmouth Hovercraft service, engineers are confident that the scheme could get off the ground; their concerns centre around the need to keep the electrified third rail away from shipping, particularly small sailing craft whose crews may not be familiar with the danger posed by a 600V, 500A-carrying bare conductor rail just inches from the surface of the salt water.
The plan calls for a new route southwards from Morden, the Northern line's present southern terminus, with several intermediate stations en route - including access platforms for all four of the Solent's historic defensive sea-forts. Although some commentators have questioned the need for a new route through Hampshire, advocates point out that it will be underground and hence they will never know it's there except when they are in the basement and a train goes past.
The idea of linking the Isle of Wight (IoW)'s Island Line, which uses second-hand Northern Line underground stock for all its services, has been considered in the past. It was rejected on the grounds that fossilised dinosaur remains, which are particularly dense in the chalk marl of the Solent, would blunt the teeth of the Tunnel Boring Machines (TBMs). A new, more rational proposal abandons the central tenet of underground lines - their sub-surface nature - and instead relies on supporting the tube trains on a cusion of air as they cross the water. The trains would dive back under the comforting earth after making landfall to the east of the Portsmouth seafront.
The proposal has gained widespread support from transport advocates, who point out that the frequency of train services between Portsmouth and Ryde has dropped off sharply since the last train ferry left in the 1950s.
Based on their experience with the conventional Ryde-Portsmouth Hovercraft service, engineers are confident that the scheme could get off the ground; their concerns centre around the need to keep the electrified third rail away from shipping, particularly small sailing craft whose crews may not be familiar with the danger posed by a 600V, 500A-carrying bare conductor rail just inches from the surface of the salt water.
