Q: How is a rail spike installed?
A: Installation method depends on the spike type:
Cut Spikes: Are driven in with a heavy sledgehammer or, more commonly, a powered spike mauler (a hydraulic or pneumatic hammer mounted on a machine).
Screw Spikes: Require a pre-drilled hole and are installed using a high-torque electric or hydraulic wrench that spins them into the sleeper.
Proper installation is crucial to avoid damaging the sleeper and to achieve the required holding power.
Q: What is "spike kill" and why is it a problem?
A: "Spike kill" refers to the phenomenon where a spike becomes loose and loses its holding power in the wooden sleeper. This is often caused by the sleeper wood shrinking, splitting, or rotting around the spike. A killed spike can no longer restrain the rail effectively, leading to gauge widening and track instability, which poses a safety risk and requires immediate attention.
Q: How do you remove a rail spike?
A: Spikes are removed using specialized tools. A claw bar or spike puller is hooked under the head of the spike. Leverage is then applied to pry the spike out of the sleeper. For large-scale operations, powered spike pullers on maintenance machines quickly and efficiently extract spikes.
Q: What is the typical service life of a galvanized rail spike?
A: The service life varies greatly depending on traffic density, environmental conditions, and sleeper type. On a standard freight line with treated wooden sleepers, a hot-dip galvanized spike can typically last 15 to 30 years before needing replacement due to corrosion or loss of holding power.
Q: Can rail spikes be reused?
A: It is generally not recommended to reuse spikes. The act of driving and pulling them out can bend the shank, deform the head, and damage the protective coating. A reused spike will not provide the same level of holding power or corrosion protection as a new spike, compromising track security.