... usual for tunnel drives of more than 1 km to be driven by mechanical digger shields or tunnelling machines and, even on shorterdrives, mechanical aids toexcavation are commonplace. While this process brings obvious benefits it is also hastening the demise of the soft ground tunnel miner whose skills...

... there were quite a number,called for critical examination of the previous methods of mechanical handling. 85. London Transport had alreadyordered the digger shields, but the problem of transporting, handling, and disposing of the spoil still remained, as well as the handling of the lining. 86. He considered...

...J V BARTLETT; T M NOSKIEWICZ; J A RAMSAY; F A HAXTON; N D PIRRIE; H J DONOVAN; R G COLE; K WYNNE BROWN; G S DODDS; T M MEGAW; J R J KING; K W TORPEY; A W SHILSTON; R F D RITCHIE © Thomas Telford and ICE 1966 SOFT GROUND TUNNELLING SUBWAYS DIGGERS SHIELDS TUNNELS COSTS HAND...

... CONCRETE EXPERIMENTAL CAST IRON DIGGERS STABILITY ELECTRICAL SCREENING BONDING SEGMENTS KNUCKLES CONTRACTS ORGANISATION EQUIPMENT TRACK CONSTRUCTION VENTILATION SIGNALLING AUTOMATIC TRAINS STATIONS UNDERPINNING VICTORIA LINE LONDON UK For discussion at an Ordinary...

... MOWLEM CENTRILINE TUNNELS WATER MAINS WATER SUPPLY LININGS GAUGES MEASUREMENT THRUST CLAYS LONDON CLAY TUNNELLING WEDGES BLOCKS SHAFTS DONSEGS PRECAST DRIVING DIGGERS MACHINERY CEMENT MORTAR MIX NOISE HAND SHIELDS DRUMS FLOW SEGMENTS COEFFICIENTS PREVENTION THAMES...