LYCOS RETRIEVER 
Channel Tunnel: St Pancras
built 656 days ago
At the end of the tunnel the visitors found one of the Beaumont compressed air boring machines at work. The length of this machine from the borer to the tail end is about 33 feet. Its work is done by the cutting action of short steel cutters fixed in two revolving arms, seven cutters in each, the upper portion of the frame in which the borer is fixed moving forward 5/16ths of an inch with every complete revolution of the cutters, In this way a thin paring from the whole face of the chalk is cut away with every turn of the borer, A man in front shovels the crumbled debris into small buckets, which, traveling on an endless band, shoot the dirt into a skip tended by another man. The skip when filled is run along a tramway to the mouth of the shaft. At present these trolleys, each holding about one third of a cubic yard, are drawn by men; but before long it is hoped that small compressed air engines will be used for traction. The rate of progress is about one hundred yards per week, but will soon be much accelerated. As worked at present, the number of revolutions it makes is two or three per minute, which amounts to bring nearly an inch a minute while the machine is at work.
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BBC: French customs officers say they have seized 35.65kg (78.6lb) of opium at the entrance to the Channel Tunnel - the largest seizure of the drug in France. The drug, with a street value of 534,750 euros (£360,181; $668,437), was found hidden in the spare tyre and other parts of a car at Coquelles.
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The shape which the completed tunnel will assume will probably be a circle, 14 feet in diameter, but flattened at the bottom to receive the rails. It will be lined with two feet thickness of cement concrete; not that this is necessary to ensure the stability of the work, but to prevent accidental falls of chalk. The concrete will be made of shingle from Dungeness, and of cement formed from the grey chalk excavated from the tunnel itself. In this manner, the tunnel will afford the means of its own lining at a cheap rate. The gradients will be 1 in 80, on each side, until the depth of 150 feet below the bottom of the sea is reached; after which the line may be said to be level, subject only to a very slight inclination from the centre outwards, to prevent the lodgings of water.
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The scheme proposed was a railway tunnel comprising two main running tunnels and a service tunnel. As in the current design vehicles were to be driven on to special wagons at the passenger terminals near the tunnel mouth. Work started with an access tunnel being driven from the top of Shakespeare Cliff to the base of the cliff and a second access tunnel from the lower site down to a level where the tunnelling machine would begin driving the pilot tunnel.
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The adit joins the tunnel after passing below a railway tunnel. At the left of the junction is a timber lined area which is believed to be the stable area for pit ponies and to the right is the bore itself. Here the floor has timber laid on it but it's rotten and tends to give way if stepped on too heavily. The tunnel wasn't lined in any way as it was only a test.
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Prof. R Mortimore undertook SEM analyses on behalf of TML on a limited number of fracture surface samples recovered from the Marine Service Tunnel in the area of the worst tunnelling conditions encountered. The results proved the presence of limited mineralisation of the fracture surfaces which might be attributable to early stages of weathering. Even with this slight mineralisation, the fracture spacing clearly indicated Grade II chalk.
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