Vic Stevens of Maunsell Rail (NCE last week) clearly has a dilemma in trying to persuade Railtrack to raise tunnel roofs by 300mm to enable 4m high HGVs to be carried piggyback. In Railtrack's position there are great risks involved in enlarging tunnels over 100 years old, when the quality of construction is not clear and the state of the unseen lining materials unknown.
There is a simpler solution to gaining 300mm of height, which does not need any alterations to the tunnel roof or electrical catenery, and can be undertaken incrementally while allowing trains to continue operating. The use of the low profile LR55 track system lowers rail height in existing tunnels, without any structural changes. The finished track is also safer with its continuos check rail and a totally level surface flush with the rail head, making tunnel and track maintenance easier, using road based maintenance easier, using road based mechanical plant.
The use of LR55 would not only mean that HGVs could be carried piggyback, it would also open the possibility of double deck carriages.
Professor Lewis Lesley (M), professor of transport, School of the Built Environment, Liverpool John Moores University, 98 Mount Pleasant, Liverpool