Types of Railroad Screw Spikes
Railroad screw spikes have been a fundamental component of railroad infrastructure for over a century. These robust metal fasteners secure wooden railroad ties, ensuring track stability and safety for train operations. As railroad technology has evolved, screw spike designs have diversified to accommodate various environmental conditions, track usage patterns, and train types.
Cut Spikes
Manufactured by cutting larger steel pieces into precise spike shapes, cut spikes feature sharp, flat bottoms that dig deeply into wooden ties when hammered. This design prevents movement and loosening over time, making them particularly effective in regions with heavy freight traffic.
Best for: High-traffic freight lines, traditional railroad construction
Chairs and Fastenings
Used primarily where tracks are laid on concrete or steel foundations, chairs and specialized fastenings hold rails in position without traditional ties. These components are critical for maintaining track gauge and stability in high-speed rail corridors.
Best for: Concrete/steel foundations, urban transit systems
High-Speed Rail Fastenings
For high-velocity train operations, specialized elastic fastenings complement standard spikes to reduce vibration and ensure passenger comfort. These sophisticated systems maintain track integrity during extreme speed conditions.
Best for: Passenger comfort, high-speed rail networks
Expert Tip: The coating applied to railroad spikes significantly impacts their lifespan. In harsh environments, zinc galvanization can extend service life by 15-20 years compared to uncoated spikes. This protective layer forms a sacrificial barrier that corrodes before the underlying steel, preserving structural integrity.
| Spike Type | Primary Application | Key Advantages | Environmental Considerations |
|---|---|---|---|
| Cut Spikes | Wooden tie systems | High holding power, traditional installation methods | Requires protective coating in wet environments |
| Chairs and Fastenings | Concrete/Steel foundations | Superior stability, extended service life | Excellent for coastal/high-humidity regions |
| Coated Spikes | All-weather applications | Enhanced corrosion resistance, reduced maintenance | Environmentally friendly zinc/epoxy options available |
| High-Speed Fastenings | Passenger express routes | Vibration reduction, enhanced ride comfort | Special consideration for temperature fluctuations |
| Pre-stressed Systems | Heavy freight corridors | Maximum stability, reduced track deformation | Suitable for extreme load conditions |
Specifications and Maintenance of Railroad Screw Spikes
Understanding the technical specifications of railroad screw spikes is essential for proper selection, installation, and maintenance. These critical components must meet rigorous standards to ensure railroad safety and operational efficiency.
Length
Railroad screw spikes range from 6 to 12 inches in length, with specific applications for each size variant. Longer spikes (10-12 inches) provide optimal stability for straight track sections, while shorter spikes are better suited for curves and softer wood varieties where splitting is a concern.
Diameter
The thickness of railroad spikes typically ranges from 0.25 inches (1/4 inch) to 0.375 inches (3/8 inch). Diameter directly influences holding strength and load capacity, with heavier rail lines requiring thicker spikes to withstand greater forces and vibrations.
Material
Modern railroad spikes are predominantly manufactured from high-carbon steel, though historical iron spikes remain in service in some regions. Steel offers superior tensile strength and durability, crucial for withstanding the dynamic forces exerted by passing trains.
Head Shape
Common head designs include flat, round, and square profiles, each offering specific advantages. Flat heads facilitate efficient driving and extraction, round heads minimize wood damage during removal, and square heads provide maximum gripping surface for installation tools.
| Specification | Standard Range | Performance Impact | Maintenance Considerations |
|---|---|---|---|
| Tensile Strength | 60,000-80,000 PSI | Resistance to pulling forces | Regular inspection for bending/deformation |
| Hardness | Rockwell B80-95 | Wear resistance during installation/removal | Tool compatibility and wear assessment |
| Coating Thickness | 3-5 mils (zinc) | Corrosion protection duration | Visual inspection for coating integrity |
| Load Capacity | 5,000-8,000 lbs | Maximum weight support | Stress testing under simulated conditions |
Key Maintenance Factors for Railroad Screw Spikes
- Corrosion Inspection: Regular visual examination for rust formation, particularly at the wood-metal interface where moisture accumulates.
- Torque Verification: Periodic checking of fastening torque to ensure specifications remain within operational parameters.
- Coating Integrity: Assessment of protective layers for scratches, chips, or wear that could compromise corrosion resistance.
- Vibration Effects: Monitoring for loosening caused by repeated train passages, especially in high-traffic corridors.
- Environmental Adaptation: Adjusting maintenance schedules based on local climate conditions, with more frequent inspections in coastal or high-precipitation areas.
Maintenance Pro Tip: Apply a small amount of anti-seize compound to screw spike threads during installation to facilitate future removal and prevent galvanic corrosion between dissimilar metals. This simple step can reduce maintenance time by up to 40% and extend the service life of both the spike and the wooden tie.
How to Choose Railroad Screw Spikes
Selecting the appropriate railroad screw spikes requires careful consideration of multiple factors including track requirements, environmental conditions, and compatibility with existing infrastructure. The right choice ensures optimal performance, safety, and longevity of the rail system.
Track Requirements Analysis
Evaluate critical parameters including track gauge, rail profile, expected traffic density, and maximum load requirements. For high-traffic mainlines, select spikes with superior holding power and fatigue resistance to withstand frequent train passages.
Key consideration: Match spike specifications to expected load frequency and weight
Environmental Assessment
Analyze local climate conditions to determine appropriate corrosion protection. Coastal areas with high salinity require enhanced corrosion-resistant spikes, while regions with extreme temperature fluctuations benefit from spikes with superior thermal expansion properties.
Key consideration: Prioritize environmental durability for long-term cost efficiency
Important Selection Warning: Never compromise on spike material quality or dimensional specifications to reduce initial costs. Substandard spikes can lead to accelerated track degradation, increased maintenance frequencies, and potentially serious safety risks. Always verify that selected spikes meet or exceed industry standards such as AREMA (American Railway Engineering and Maintenance-of-Way Association) specifications.
| Selection Factor | Evaluation Criteria | Recommended Specifications |
|---|---|---|
| Traffic Volume | Trains per day, average weight | Heavy traffic: 5/8" diameter, high-carbon steel Light traffic: 1/2" diameter standard steel |
| Wood Tie Characteristics | Wood hardness, grain structure, age | Hardwood: Shorter spikes with chisel points Softwood: Longer spikes with sharp points |
| Climate Conditions | Precipitation, temperature range, humidity | Wet climate: Hot-dip galvanized coating Dry climate: Standard coating or uncoated |
| Installation Method | Available equipment, labor expertise | Machine installation: Compatible head design Manual installation: Ergonomic grip features |
Selection Expert Tip: Consider the lifecycle cost rather than just the initial purchase price when selecting railroad spikes. Higher-quality spikes with enhanced corrosion protection may cost 15-20% more initially but can reduce replacement frequency by 50% or more, resulting in significant long-term savings in materials, labor, and track downtime.
How to DIY and Replace Railroad Screw Spikes
While railroad spike replacement is typically performed by professional maintenance crews, it can be approached as a DIY project with proper preparation and safety precautions. This guide outlines the essential tools, materials, and step-by-step process for successfully replacing railroad screw spikes.
Required Tools
- Claw hammer or spike maul
- Rail gauge measurement tool
- Protective gloves and eyewear
- Track alignment jig
- Spike puller (for removal)
Materials Needed
- Replacement railroad screw spikes (correct size/type)
- Wood preservative for tie holes
- Anti-seize compound (optional)
- Hardwood plugs (for abandoned holes)
- Track marking chalk
Step-by-Step Replacement Process
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Safety Preparation
Before beginning work, verify the track is out of service with appropriate signaling and notifications. Wear all required safety equipment including gloves, eye protection, and high-visibility clothing. Establish clear communication protocols if working with a team.
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Remove Deteriorated Spike
Position the claw end of the hammer or spike puller under the head of the old spike. Apply steady leverage, working the spike upward gradually to minimize tie damage. If the spike is severely corroded or broken, you may need to use additional tools such as a spike drift pin to drive out the remaining portion.
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Inspect and Prepare Tie
Examine the tie condition where the spike was removed. Clear any debris from the hole and check for splitting or deterioration. Apply wood preservative to the hole to extend tie life. If the tie is damaged beyond reuse, mark it for replacement and select an alternate insertion point.
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Check Rail Alignment
Use the rail gauge to verify proper track spacing and alignment before installing the new spike. Make any necessary adjustments to ensure the rail is properly positioned against the tie plate. This critical step prevents improper track geometry that could lead to operational issues.
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Install New Spike
Position the new screw spike perpendicular to the tie surface and begin driving it with controlled hammer strikes. Maintain vertical alignment throughout installation to prevent bending. Drive the spike until the head makes firm contact with the rail base or tie plate, but avoid over-driving which can damage the wood.
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Verify Installation
Check that the spike is properly seated and the rail is secure. Confirm proper track gauge again after installation. Test the spike stability by applying moderate lateral pressure. Document the replacement according to maintenance protocols.
Safety Warning: DIY railroad maintenance should never be attempted on active rail lines or without proper authorization. Always coordinate with relevant railroad authorities and adhere to all safety regulations. Improper spike installation can lead to track failure, derailments, and serious safety hazards.
Installation Pro Tip: When driving new spikes, use a two-stage process for optimal results. Begin with lighter taps to establish proper alignment, then increase force gradually to seat the spike. This technique reduces the risk of spike bending and tie splitting while ensuring proper installation depth.
Frequently Asked Questions
Railroad screw spikes don't have a predetermined replacement schedule but rather should be replaced based on condition assessments during regular track inspections. Factors affecting replacement frequency include:
- Traffic volume and weight (heavy freight vs. light passenger)
- Environmental conditions (moisture, temperature extremes)
- Track geometry (curves require more frequent inspection)
- Spike material and coating quality
Most Class 1 railroads conduct visual inspections at least weekly, with comprehensive spike condition assessments quarterly. Replacement typically occurs when spikes show significant corrosion (>25% material loss), bending exceeding 15 degrees, or when loosening is detected.
Reusing railroad spikes is generally not recommended for several safety and performance reasons:
| Factor | Impact on Reused Spikes | Safety Implications |
|---|---|---|
| Metal Fatigue | Microscopic structural changes from repeated stress | Reduced load capacity, unexpected failure |
| Deformation | Subtle bending or thread damage | Compromised holding power, track instability |
| Corrosion | Surface pitting, material loss | Weakened structural integrity, accelerated failure |
| Coating Damage | Compromised protective layers | Accelerated deterioration in second installation |
For non-critical applications such as landscaping, craft projects, or non-load-bearing fixtures, recovered spikes may be suitable. However, in operational railroad applications, only new spikes meeting current specifications should be used to ensure safety and performance.
Professional railroad spike installation involves several precise steps:
- Pre-drilling: Pilot holes are created in wooden ties to guide the spike and prevent wood splitting. The hole diameter is typically 60-70% of the spike diameter.
- Positioning: The spike is aligned perpendicular to the tie surface with the head oriented to engage the rail base or tie plate properly.
- Driving: Using specialized equipment such as hydraulic spike drivers or pneumatic hammers, the spike is driven into the tie with controlled force. On mainline tracks, automated spike driving machines can install multiple spikes simultaneously.
- Seating: The spike is driven until properly seated against the rail, with the head making firm contact with the rail base or tie plate.
- Verification: Track geometry is verified after installation using precision measurement tools to ensure proper gauge and alignment.
Modern rail maintenance operations typically employ specialized machinery for spike installation, which ensures consistent driving force, proper alignment, and increased efficiency compared to manual methods.
Cut spikes and screw spikes represent different fastening technologies in railroad construction, each with distinct characteristics:
Cut Spikes
- Driven straight into wood ties
- Smooth shank design
- Relies on friction and compression for holding power
- Faster installation, lower initial cost
- Traditional North American design
Screw Spikes
- Threaded design that screws into ties
- Helical thread pattern
- Superior holding power and vibration resistance
- Slower installation, higher initial cost
- Common in European and high-speed rail systems
Screw spikes generally provide 30-40% greater holding power than traditional cut spikes, which makes them preferred for high-speed rail applications where maintaining precise track geometry is critical for passenger comfort and safety.