I had decided not write any more “balderdash” on the subject of the BML2 but Brian Hart’s reference to the London Cross Rail project led me to check it.
I discovered that there are two single track tunnels, a further check on the Euro Rail tunnel system reveals three single track tunnels including the service one. As the tunnels with lining need a circular cross section for maximum strength I’m afraid BML2 will need two tunnels, so one “coring” machine or two?
The machines each weigh just over 1,000 tonnes and come with a conveyor belt system to carry the soil back to the tunnel entrance for disposal. A further complication is that conveyors only work in straight lines, therefore no curved tunnels under the Downs as proposed by Mr Hart.
Now for the bridge. On the first page, he shows the rail bridge over the cutting for the A27 a clever piece of engineering, with the note “Similar rail bridge (shown here across A27) to be provided”.
Incorrect, the rail bridge over the A27 west of the Kingston roundabout is altogether different. According to the OS map it is over 300 metres long and curved and will be constructed over the busy A27, some “picnic”. Coupled with all this there isn’t the space for a construction site for the bridge or the tunnel.
There is one more local tunnel not mentioned, the tunnels emerge on the Landport flood plain where the tracks cross to the Lewes–London line which the BML2 will tunnel under! No comment needed.
Director of the Balderdash Campaign