Why Some Railway Fishplates Have No Holes?

A rail fish plate is a mechanical rail connector that restores effective load transfer at rail joints, ensuring wheel loads are distributed across adjacent rails rather than concentrated at the rail gap. GNEE RAIL offers fish plates for GB rail standards, UIC50–UIC60, DIN536 A-series crane rails, QU crane rails, JIS rail types, AS1085 rails, BS11 profiles, and AREMA/ASCE rails, supported by joint performance assessment.

Why Some Railway Fishplates Have No Holes?

Railway fishplates without holes are designed specifically to be welded directly to the rail track rather than bolted. This method improves structural rigidity, prevents the joint from loosening, and eliminates maintenance required for bolted connections.

Key Reasons for No-Hole Fishplates:

• Welding Efficiency: The absence of holes provides a solid surface for better, faster welding, increasing stability in high-stress areas.

• Reduced Maintenance: Bolted joints often loosen (50-70% reduction in bolt preload) due to vibration. Welded joints eliminate this maintenance requirement.

• Safety and Durability: They are used when a more permanent, rigid connection is required compared to traditional bolted joints.

While most fishplates feature 4 or 6 holes for fastening, the hole-less variety is a specialized component used to improve the overall integrity of the railway track system.

Main Types of Rail Joint Bar

Rail joint bars, or fishplates, are essential components connecting rail tracks, categorized by function into common (standard), insulated, compromise, expansion, and joggled types. They are primarily used in 4-hole or 6-hole configurations, manufactured via casting, forging, or rolling to provide structural continuity and safety.

Here are the main types of rail joint bars based on their function and design:

• Common/Standard Rail Joint Bar: These are the most common, used for connecting two rails of the same type and size (e.g., 43kg, 50kg, 60kg, or 115RE). They are usually available in 4-hole or 6-hole varieties to maintain a consistent, strong connection.

• Insulated Rail Joint Bar: Designed for electrical insulation in automatic block districts to control traffic signal systems. These high-strength, composite material joints are resistant to corrosion and electricity.

• Compromise Rail Joint Bar: Specifically designed to connect two different types or sizes of rail tracks together. They ensure a smooth, level, and safe transition, often used in switches and crossings.

• Expansion Rail Joint Bar (Temperature Regulators): Used in locations experiencing significant temperature variations, allowing for expansion and contraction of rail ends. These prevent stress buildup in the track.

• Joggled/Bulge Rail Joint Bar: These feature a prominent bulge in the center and are primarily used for repairing broken or cracked welded rails, often as a temporary, emergency measure.

What is the diameter of a rail hole normally provided for a fish plate joint?

The diameter of a rail hole for a fish plate joint is typically 25 mm to 32 mm, designed to be slightly larger than the fish bolt to allow for rail expansion. Common sizes include 25.4 mm (1 inch), 26 mm, 27 mm, or 31.8 mm depending on the rail section (e.g., UIC60, 115RE, 132RE) and standard.

• Standard Bolt Diameters: Often 25 mm (BG), 22 mm (MG), or 18 mm (NG), with holes drilled larger.

• Hole Shapes: Holes can be round or oval (commonly 32mm).

• Fish Plate Type: Different standards (AREMA, BS, UIC) and rail weights dictate specific hole diameters.

Founded in 2008, GNEE RAIL is a leading global manufacturer and supplier of railway components, specializing in high-quality rail fish plates (joint bars/splice bars) with strong production capacity and global service capabilities.

Our rail fish plate portfolio is comprehensive and compliant with international standards including UIC, AREMA, BS, DIN, and GB, covering light rail (8kg-30kg), heavy rail (38kg-75kg), and crane rail (QU70-QU120) systems. We offer diverse types such as insulated joint bars, bulged fish plates, and compromise rail joints,with precise specifications (4-hole/6-hole, 24-inch/36-inch), ensuring excellent mechanical performance.We uphold strict quality control supported by ISO 9001:2015 certification, an in-house inspection center, and third-party audits by SGS and BV. Our one-stop service includes customization, production, packaging, and after-sales support, tailored to clients' project needs.

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