When disposing of muck in a very long tunnel with a small diameter, which transportation system is usually the most efficient?
- AManual labour with wheelbarrows.
- BLarge heavy-duty dump trucks.
- CNarrow-gauge rail tracks with mine cars.Correct
- DOverhead cranes.
Solution
Concept
Tunnel Muck Transportation Systems
Formula
N/A
Step-by-step solution
1. Evaluate transport options for muck disposal in long, small-diameter tunnels. 2. Identify that narrow-gauge rail tracks with mine cars provide the most efficient haulage in confined spaces over long distances. 3. Select Option C as the correct choice.
Explanation
Narrow-gauge rail tracks with mine cars are the most efficient option because they take up very little space inside small-diameter tunnels while reliably hauling large quantities of heavy excavated material (muck) over long distances.
Shortcut
To remember the best transport system for tunnel muck disposal, use the rule "Long & Narrow = Rail": - Long Distance + Small Diameter (Narrow Space) = Narrow-gauge Rail Tracks with Mine Cars - Rail tracks fit easily into tight spaces and handle long-haul transport efficiently without producing diesel exhaust fumes in confined tunnels.
Common mistake
A common mistake is selecting Option B by assuming heavy-duty dump trucks are always best for large volume haulage, while overlooking the "small diameter" constraint which limits space and ventilation for large road vehicles. Another frequent mistake is selecting Option A, assuming small space requires manual labor, while ignoring the "very long" distance involved.
Correct answer: C) Narrow-gauge rail tracks with mine cars.