Compressed Air Drill

Compressed air drill is a drill that can rip (прорезать) through rock with ease. It was first used in a tunnel
in 1866, in the Hoosac Tunnel, in North Adams, Massachusetts.

Do you know that the compressed air drill made life much easier for workers in the Hoosac Tunnel? The drill was safe and three times more effective than gunpowder. In the choking dust, the drills also had a welcome side effect (побочный эффект). Air blew out of the end of the drills and actually provided some fresh air in the stuffy Hoosac Tunnel. Before the compressed air drill, workers toiled (усиленно трудились) in hot, steamy tunnels without any ventilation!

Tunnel Boring Machine (TBMs)

Tunnel Boring Machine is a 200-ton rock-chewing (пережевывать) machine designed to carve through rock. It was first used in a tunnel in 1957 to carve a sewer tunnel through shale and limestone in Toronto, Canada.

Do you know that TBMs are very picky (разборчивы) about the rocks they chew through? This is why geologists must monitor the rock at the head of every tunnel. On good days, TBMs can bore through rock at a rate of 250 feet a day. But when TBMs bite into rocks they don’t like, they grind to a halt (усердно трудится до остановки) and conk out (ломаться). Many tunnel engineers have been forced to abandon (оставлять) their TBMs because they can't back them out of the tunnel!

Tunnel Shield

Tunnel shield is an internal frame, or shield, used to support loose earth in a tunnel while digging. It was first used in a tunnel in 1825, to excavate the Thames Tunnel, London, England.

Do you know that the idea for the tunnel shield was borrowed by a French engineer named Marc Brunel from nature and a helmet-headed shipworm (корабельный червь) gave that idea? The worm bore through wood, using the hard shell (остов) on its head as a shield. As it tunneled into the wood, the worm excreted a substance that formed a rigid (твердый) lining behind it!

1.16. Are the following statements false or true? Write down your answers.

1. Fire-setting was first used in a tunnel around 1000 B.C., to mine coal from Egyptian mountains.

2. In spite of disadvantages fire-setting remained the standard tunnel digging method for over 5,000 years.

3. Hand tools were first used in a tunnel around 2000 B.C. to mine copper, gold, and salt from mountains in England.

4. Gunpowder was first used in 1679, to build an underground section of the Canal du Midi, and dynamite was first used only in 1867.

5. Compressed air drill was safe and three times more effective than gunpowder.

6. Tunnel Boring Machine was first used in 1957 to excavate the Thames Tunnel, London, England.

7. Tunnel shield is an internal frame, or shield, used to support loose earth in a tunnel while digging.

8. The idea of a tunnel shield was borrowed from nature by Marc Brunel.

Дата добавления: 2015-10-31