1. How do you calculate required spike quantity per km?
Formula:
Spikes/km = (1000/Tie spacing) × Spikes per tie
Example:
600mm tie spacing × 4 spikes = 6,666 spikes/km
Add 5% extra for curves and joints.
2. What are the differences between dog spikes and screw spikes?
| Feature | Dog Spike | Screw Spike |
|---|---|---|
| Installation | Hammer-driven | Torque wrench |
| Holding Power | 3-5kN | 8-12kN |
| Lifespan | 10-15 years | 20-25 years |
| Cost | $0.50/unit |
$1.20/unit |
3. How are spikes protected in electrified corridors?
Special measures include:
Fiberglass-reinforced nylon washers
Double-layer epoxy coating
Zinc-aluminum alloy plating
Prevents stray current corrosion that can degrade spikes 3x faster.
4. What's the procedure for replacing damaged spikes?
Remove ballast around the tie
Extract old spike with puller
Clean/debris the hole
Insert new spike at correct angle
Drive to flush position
Recompact ballast
Takes 3-5 minutes per spike with proper tools.
5. How does spike length vary by tie material?
Wooden ties: 130-150mm
Concrete ties: 100-120mm (shorter due to higher density)
Composite ties: 110-130mm
Longer spikes are used in softwood ties versus hardwood.