1. What are the main differences between wooden and concrete railway sleepers in terms of durability?
Wooden sleepers typically last 15–25 years with proper maintenance, while concrete sleepers have a lifespan of 30–50 years due to their resistance to rot and wear.
2. How do steel-reinforced concrete sleepers differ from plain concrete sleepers in load-bearing capacity?
Steel-reinforced concrete sleepers can withstand higher axle loads (up to 30 tons) due to embedded steel bars that enhance tensile strength, whereas plain concrete sleepers are limited to 20–25 tons.
3. What makes composite sleepers (fiberglass + plastic) suitable for electrified railways?
Composite sleepers are non-conductive, preventing electrical current leakage between rails and the trackbed, which is critical for electrified systems to avoid short circuits.
4. How do narrow-gauge sleepers (1067mm) differ from standard-gauge sleepers (1435mm) in terms of spacing?
Narrow-gauge sleepers are spaced closer together (500–600mm) to improve stability, while standard-gauge sleepers have wider spacing (600–700mm) to balance weight distribution.
5. What material properties make hardwood sleepers better than softwood sleepers for heavy-haul railways?
Hardwood sleepers have higher density and compressive strength, resisting deformation under heavy axle loads (25+ tons) better than softwood, which may compress over time.