How do fish plates ensure rail alignment?
Dec 31, 2025
Rail fishplate, which is bolted to the ends of two railroad tracks to join them together, is widely used in light rail, heavy rail and crane rail. So if the quality of the railway fish plate is poor, the caused consequence would be unimaginable. As to the fastening system, fish bolt is the other important part and always firstly chosen in the part of fastening. In general, the rail fastening system is consisting of fish bolt, flat washer and spring washer. Every two fishplates mostly need four or six suits of fish bolt.
How do fish plates ensure rail alignment?
Fish plates (or joint bars) ensure rail alignment by physically connecting two rail ends side-by-side, using bolts to clamp them together so their running surfaces match perfectly in height and direction, creating a continuous, stable path for trains while allowing for thermal expansion and load transfer. Their tapered design helps wedge the rails into precise alignment as bolts are tightened, maintaining structural integrity and preventing gaps or misalignment.
How track splint Work:
- Physical Connection: The fish plate, a long metal bar, fits snugly over the web (the vertical part) of two adjacent rail ends.
- Bolt Fastening: Holes in the fish plate align with holes in the rail ends, and bolts are passed through and tightened.
- Tapered Design: Fish plates have a slight taper on their top and bottom edges. When the bolts are tightened, this taper wedges the plate firmly against the rail, ensuring the top surfaces (running surface) are flush and level.
- Load Transfer: They distribute the immense weight and impact forces from train wheels across both rail ends, preventing localized stress and ensuring smooth passage.
- Stability: By holding the rails rigidly together, they prevent lateral (sideways) and longitudinal (forward/backward) movement, ensuring the track stays straight and stable.
- Thermal Movement: The slight gap and the ability for the plate to slide slightly (when lubricated) allows rails to expand and contract with temperature changes without buckling or breaking the joint.
Types of Fish Plates
Several types of fish plates are employed in railway installations to address various needs and rail types. Common variations include standard fish plates, which are used for general applications. Compromise fish plates are designed to join rails of different sizes or profiles and are essential for transitional sections of a track. Insulated fish plates, on the other hand, prevent electrical currents from passing between joined rail ends, playing a pivotal role in track signaling and control systems. Lastly, the specialized fish plates are used in heavy-duty railways to withstand high loads and extreme conditions, thereby enhancing the longevity and reliability of the rail infrastructure.
GNEE RAIL supplies rail fishplates for light rail, heavy rail, and crane rail systems. Each model is manufactured to international railway standards and available in carbon steel, alloy steel, or customized materials to meet specific operational needs.All fishplates undergo precision machining, heat treatment, and anti-corrosion surface processing, ensuring optimal clamping force, fatigue resistance, and long-term service life.
| Rail Type | Standard Length (mm) | Width (mm) | Thickness (mm) | Hole Diameter (mm) | Hole Spacing (mm) | Bolt Size | Material Options | Surface Treatment |
|---|---|---|---|---|---|---|---|---|
| 43kg Rail Fishplate | 800 | 65 | 16 | 22 | 90/105 | M22 | Carbon Steel / Alloy Steel | Oiled / Galvanized / Painted |
| 50kg Rail Fishplate | 800 | 65 | 20 | 24 | 100/120 | M24 | Carbon Steel / Alloy Steel | Oiled / Galvanized / Painted |
| 60kg Rail Fishplate | 860 | 70 | 20 | 24 | 100/120 | M24 | Carbon Steel / Alloy Steel | Oiled / Galvanized / Painted |
| QU70 Crane Rail Fishplate | 760 | 70 | 20 | 24 | 90/105 | M24 | Carbon Steel / Alloy Steel | Oiled / Galvanized / Painted |
| QU80 Crane Rail Fishplate | 820 | 75 | 20 | 24 | 100/120 | M24 | Carbon Steel / Alloy Steel | Oiled / Galvanized / Painted |
| QU100 Crane Rail Fishplate | 950 | 80 | 22 | 26 | 105/125 | M27 | Carbon Steel / Alloy Steel | Oiled / Galvanized / Painted |
| QU120 Crane Rail Fishplate | 1050 | 85 | 26 | 26 | 110/130 | M27 | Carbon Steel / Alloy Steel | Oiled / Galvanized / Painted |
Other Types of Rail Joint
| Model | Material | Standard | Unit weight | Surface Treatment | |
|---|---|---|---|---|---|
| SJ50 rail joint | 50# | 11.59kg/pc | Plain | ||
| SJ43 Rail Joint | 50# | 10.16kg/pc | Plain | ||
| TJ57 Rail Joint | 45# | 17.36kg/pc | Plain | ||
| S30 Rail Joint | 50# | 5.8kg/pc | Plain, or according to the customers' demand | ||
| CR135 Rail Joint (used in CR135 Crane Rail) | 50# | ASTM-43 | Plain, or Hot-dip galvanized |
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| CR171 Rail Joint (used in CR171 Crane Rail) | 50# | ASTM-43 | 16.0kg/pc | Plain, or Hot-dip galvanized |
|
| S49 Forged Rail Joint |
Q345 | UIC49 | 8.60kg/pc | Sandblasted +oiled | |
| S60 Forged Rail Joint |
Q345 | UIC60 | 14.50kg/pc | Sandblasted +oiled |
GNEE RAIL can provide you with different rail joints such as GB, AREMA, BS, UIC, AS, African standard, South American standard, and different types such as common rail joint, compromise rail joint, bulge rail joint, insulated rail joint and glued insulated rail joint, etc. Our products have been exported to more than 20 countries and areas and more than 50 types of rail joints of standard and nonstandard are available for global customers.
