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1. The accumulation of dust in railway tunnels can cause the worse conditions for passengers trying to escape in an (аварийная ситуация).
2. Coarse dust, predominantly (песок), accumulates on the track, while fine dust composed of alumina, graphite and silicate sticks to the tunnel walls and (своды) because of a strong electrostatic bond.
3. The leaves that fall during autumn are blown into the railway tunnels by strong winds. They are compressed by passing trains (колеса) into a thin layer on the railhead and some sections of railway are brought to a halt.
4. If there is a heavy (накопление снега и льда), mechanical means should be used to remove as much as possible before a deicing chemical is applied.
5. Testing is being done in the tunnel when it is not in use. When a track (повреждение) is identified, time is of the essence. A track maintenance gang makes decisions and acts fast.
6. During the construction of a tunnel, fire safety, dust separation and cooling are important aspects to meet modern standards for health and (безопасность) at work.
7. (Пыль) is typically deposited by mechanical filters or water sprays where solid particles adhere to water droplets.
8. Fire and (дым) are usually dealt with by a ventilation system. If no escape path is nearby, fire suppression systems and shelter areas are required additionally.
Work in pairs. Make up your own dialogues. Student A will be the engineer, working with a team of specialists, who are responsible for after-inspection repairin the tunnel. Student B will represent the designer who consults the workers. They are discussing the challenges the tunnel faces. Use the following word combinations for your questions and phrases for possible answers.
Could you; I’d like to know; Can you tell me; What about; We need; We really must; We ought to; We can manage it; It isn’t necessary; We don’t have to; We can do without; It was good planning; It was more than just laying the track; We didn’t change the structural look of it, but it looks better because we upgraded all of the lighting systems; The lighting is a big deal; When you’re talking about a three-mile tube underground, lighting becomes very important; There was some water damage that had crept in; This tunnel is the economic engine of the region, and now it’s becoming more accessible to traffic.
Unit 23
COLLAPSE OF RAILWAY AND MOTORWAY ENGINEERING STRUCTURES
