Answer the questions. 1. What are the main factors of air contamination in tunnels?

1. What are the main factors of air contamination in tunnels?

2. Are there any distinct operations in tunnel maintenance? What are they?

3. What problems can the accumulation of dust cause in railway tunnels?

4. What does a maintenance crew examine to prevent derailment?

5. What instruments can test tunnel height and width clearances?

6. Do the gutters appear to be one of the vital elements in tunnel operation?

7. Why are the ventilation facilities so essential for motorway tunnels?

8. What ventilation types are suitable in tunnels?

9. Why do safety measures depend on tunnel lightning?

23.7 Make up your own dialogues. Student A is the engineer, working with a team of specialists, responsible for after-inspection repairin the tunnel. Student B is the expert who consults the workers. They are discussing the tunnel problems. Use the following word combinations

Could you; I’d like to know; Can you tell me; What about; We need; We really must; We can manage it; It isn’t necessary; We don’t have to; We can do without; It was good planning; 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