Why are rail fish plates adopted for DIN S18 steel rails?
The use of mechanical joint bars, universally known as rail fishplates (or splice bars), is the standard engineering practice for joining DIN S18 steel rails (18.30 kg/m). Because the S18 profile is a light rail primarily deployed in underground mining loops, factory transfer lines, and automated warehouse tracks, field-welding methods (like thermite welding) are often impractical, cost-prohibitive, or structurally restrictive.
Rail fishplates provide a highly reliable, low-maintenance mechanical splicing solution that matches the service demands of light rail infrastructure.
1. Absorbing Thermal Expansion and Contraction
Steel rails expand when temperatures rise and contract when they fall. If a track line is welded into a continuous, rigid ribbon of steel without relief points, thermal stress can cause the track to buckle horizontally in summer or fracture completely in winter.
- The Fishplate Solution: S18 fishplates are installed with a calculated physical gap (expansion gap) between the two rail ends.
- Slotted Bolt Holes: The bolt holes in the fishplates are elongated or oversized. This allows individual S18 rail lengths to slide horizontally back and forth within the joint assembly as temperatures change, relieving internal stress and protecting the alignment from structural warping.
2. Ensuring Smooth Wheel Transitions and Vertical Alignment
The DIN S18 rail has a slender 93.0 mm height and a narrow 43.0 mm head. When a loaded ore car or light gantry wheel transitions from one rail segment to the next, any vertical or lateral offset between the two rail ends will create a sharp step.
- Preventing Impact Damage: S18 fishplates are hot-rolled and precision-machined to match the exact fishing height (the sloped space between the rail head and base) of the DIN 5901 profile.
- Bridging the Load: By clamping tightly into the web area on both sides of the joint, the fishplates bridge the vertical wheel load, ensuring that the rail heads stay perfectly flush. This eliminates wheel-chipping impacts and preserves the lifespan of the vehicle bearings.
3. High Cost-Efficiency and Ease of Maintenance
In confined environments like underground mine drifts or complex industrial facilities, deploying heavy welding crews and inspection equipment is logistically difficult.
- Rapid Assembly: Fishplate joints can be assembled or replaced in minutes by a small crew using standard hand tools or impact wrenches.
- Component Salvage: If a section of the S18 track wears out or suffers mechanical damage, the fishplates can be unbolted quickly to swap out the damaged rail piece without destroying the neighboring track.
Your Full-System Supply Partner: GNEE RAIL
When engineering an S18 track layout, sourcing components that are rolled to different regional standards can cause severe tracking and fitment errors. To ensure seamless mechanical compatibility and eliminate joint steps, the entire track assembly should be procured as an integrated system.
As a leading global manufacturer and exporter of international track materials, GNEE RAIL provides full-system component matching for European light rail tracks:
- DIN 5901 S18 Rails: Available in standard fixed lengths (e.g., 6m, 8m, 10m) rolled from premium, wear-resistant R260 or R200 steel grades.
- Matching S18 Rail Fishplates: Precision-engineered 4-hole flat or angled splice bars configured to fit the exact 93.0 mm profile height and fishing angles of the S18 rail.
- High-Tensile Rail Bolts: Heavy-duty M12 / M14 fishbolts paired with matching hex nuts and split spring washers, manufactured to Grade 8.8 specifications to ensure high clamp retention under continuous rolling vibrations.
FAQ
- What is the lead time for a custom run of S18 rails if my mining site requires specific pre-drilled fishplate hole spacing?
GNEE RAIL operates fully automated multi-spindle drilling lines integrated directly into our finishing cooling beds, which allows us to customize your joint hole arrays mid-production without extending standard lead times. For typical bulk orders requiring bespoke hole placement, we maintain highly synchronized rolling schedules that deliver your finished track batch weeks faster than generic steel brokers.
- Can your mill guarantee that the S18 rail bundles will not bend or warp during long-distance maritime container shipping?
GNEE RAIL implements a specialized industrial bundling framework where every S18 rail lot undergoes automated hydraulic straightening before being tightly hex-wrapped with high-tensile steel bands. We place high-density timber dunnage blocks at mathematically calculated support intervals beneath every strap boundary, ensuring the 18.30 kg/m sections remain perfectly straight and distortion-free throughout sea transit.
- Are the matching joint fishplates and anchoring clips manufactured in-house to ensure an exact fit on the 82.00 mm base flange?
Yes, GNEE RAIL designs and manufactures the entire ecosystem of matching fastening hardware-including rigid clips, elastic clamps, and steel joint fishplates-in the same facility as our rail profiles. This integrated manufacturing approach ensures that the splice bars contour perfectly to the 93.00 mm vertical height and the clips clamp the 82.00 mm base flange with exact torque specifications, preventing track creeping.
- What level of quality certification and traceability documentation does your mill provide with each shipment of S18 light rails?
GNEE RAIL provides complete, uncompromised material traceability by issuing official Mill Material Test Reports (MTR) tied directly to the specific heat number stamped on your rail batch. Our quality control documentation details the exact ladle chemical analysis, destructive tensile limits, surface hardness ratings, and ultrasonic defect tracking results, giving your inspection team full engineering verification that the steel meets international standards.
Get a Quote in 24 Hours
Securing long-term tracking safety and operational efficiency within narrow-gauge logistics environments relies heavily on purchasing precision-rolled steel profiles with verifiable quality documentation. GNEE RAIL fields complete rolling mill infrastructure to supply heavy-duty S18 light rails, specialized European standard track sections, and custom-engineered fastening assemblies optimized for tough material movement. Our machine shops are fully equipped to execute non-standard cross-cuts and custom tie-spacing hole placement designed to match your specific engineering layouts. Please open a channel with our commercial engineering team today to review official metallurgical certifications, analyze physical performance thresholds, and secure a transparent, factory-direct quotation to protect your facility infrastructure.
