Mammoth "Metal Moles" Tunnel Deep Beneath London 294
Hugh Pickens writes "BBC reports that the first of eight highly specialized Tunnel Boring Machines (TBM), each weighing nearly 1,000 tonnes, is being positioned at Royal Oak in west London where it will begin its slow journey east. It will carve out a new east-west underground link that will eventually run 73 miles from Maidenhead and Heathrow in the west, to Shenfield and Abbey Wood in the east. Described as 'voracious worms nibbling their way under London,' the 150-meter long machines will operate 24 hours a day and move through the earth at a rate of about 100m per week, taking three years to build a network of tunnels beneath the city's streets. Behind a 6.2-meter cutter head is a hydraulic arm. Massive chunks of earth are fed via a narrow-gauge railway along the interior of the machine, which is itself on wheels, as the machines are monitored from a surface control room which tracks their positions using GPS. Hydraulic rams at the front keep them within millimeters of their designated routes. 'It's not so much a machine as a mobile factory,' says Roy Slocombe, adding that the machine is staffed by a 20-strong 'tunnel gang' and comes with its own kitchen and toilet. Meanwhile, critics complain that the project is a peculiarly British example of how not to get big infrastructure schemes off the ground, because almost 30 years will have elapsed from its political conception in 1989 to its current projected completion date of 2018."
Re:comparative position? (Score:4, Interesting)
London's system appears to be conveniently bi-directional. [q-dog.co.uk]
Re:GPS? (Score:5, Interesting)
GPS?? Underground? Cool, so my scuba GPS is just around the corner too then.
Unless your SCUBA activities consist of walking around above the water level, I don't think you're going to find a GPS based solution to help you - water attenuates the signals too much.
However, if you're underground, there are a number of companies that can sell you GPS repeaters that will help you navigate even when you can't receive any satellite signals directly:
http://www.vialite.co.uk/gps_band_overview.php [vialite.co.uk]
http://www.leica-geosystems.us/en/GPS-Machine-Guidance_1939.htm [leica-geosystems.us]
Re:Good on London for supporting public transport (Score:4, Interesting)
About 10 years ago I was commuting via the bus for a while, and was curious about the true efficiency. So I took the total amount of fuel that the bus system was reported to use in a year, and divided by the number of passengers and total miles driven (all part of their annual report). My conclusion was that the bus system got about 12 passenger miles per gallon averaged over all their routes and schedules. Unfortunately for most people the real price of taking the bus, besided the bus fare, was the loss of time. My commute took over an hour each way, and could be driven even in bad traffic in about 25 minutes. At the time I was only making $15/hour, so the opportunity cost to me of taking the bus was very conservatively over an hour per day or $15 per day (not even counting the time to walk out to and wait for the bus, and the restriction on my work schedule - the last bus home went by at about 6:30 PM) - enough to buy a very nice car if I wanted to.