Rail Fishplate (Joint Clamp) Core Specifications and Connection Requirements
What are the core models of rail fish plates and adapted rail specifications?
Fish plates are divided into national standard and foreign standard series according to rail standards, the models fully correspond to rail specifications and types, and cannot be used across specifications. National standard fish plates are suitable for 8-75kg/m national standard rails, 50kg/m rails with 50-type fish plates, 60kg/m with 60-type, 75kg/m with 75-type, and the size fits the rail base contour. Foreign standard fish plates are suitable for UIC50/60, American standard 136RE and British standard BS80A rails, UIC60 rails with European standard fish plates, and American standard rails with American standard special fish plates. Lifting rails QU70-120 are equipped with heavy-duty fish plates with thicker thickness and more bolt holes for industrial and mining use, and standard fish plates can be used for ordinary rails. Fish plates are also divided into flat joint and bevel joint types, 45° bevel joints for expansion joints, and flat joints for conventional sections, selected as needed.
What are the core material of fish plates and core mechanical performance requirements?
The core materials of fish plates are national standard Q235, Q355 and foreign standard 900A carbon steel, all are special high-strength materials for track joints with excellent impact resistance. Q235 fish plates are suitable for light load tracks with tensile strength ≥375MPa, good plasticity, not easy to crack during installation and economical cost. Q355 fish plates are suitable for heavy-duty and high-speed railway tracks with tensile strength ≥510MPa, yield strength ≥355MPa, strong deformation resistance, and resist high-frequency wheel impact. Fish plates need to ensure the position accuracy of bolt holes with pitch deviation ≤±0.2mm to ensure smooth bolt penetration without misalignment jams. The fish plate surface is flat without burrs and cracks, and the edges are chamfered to avoid scratching the rail joint and extend the service life of rails and fish plates.
What are the core bolt configuration and locking requirements for fish plate installation?
Fish plate installation is equipped with high-strength fish bolts, the number and specification of bolts are determined by the fish plate model, national standard 50-type fish plates are equipped with 4 M24 bolts, and 60-type with 6 M27 bolts. Foreign standard UIC60 fish plates are equipped with European standard M27 bolts, American standard fish plates with American standard bolts, the bolts are precisely adapted to the fish plate holes without gap shaking. The locking torque of fish bolts is determined by the grade, 8.8 grade bolts with torque 350-400N·m, 10.9 grade with 500-550N·m, uniform torque without deviation, and unilateral over-tightening is prohibited. During installation, the fish plate is centered to fit the rail joint, the bilateral gap symmetry ≤0.3mm, and the rail joint flatness deviation ≤0.2mm to ensure smooth driving. Install spring washers for anti-loosening after locking, add lock nuts for heavy-duty tracks, inspect the torque monthly and retighten in time to avoid loosening.
What are the usage differences of fish plates for high-speed railway/ordinary railway/industrial and mining?
High-speed railway fish plates are high-speed railway special thickened type with thickness ≥20mm, made of Q355 high-strength steel, suitable for seamless line auxiliary joints, requiring extremely high joint flatness with deviation ≤0.1mm. Ordinary railway fish plates are standard type with thickness 16-18mm, made of Q235, suitable for conventional joints of ballasted tracks, flatness deviation ≤0.3mm is acceptable with more economical cost. Industrial and mining fish plates are heavy-duty thickened type with thickness ≥22mm, 2 more bolt holes, doubled locking force, resisting heavy load impact of hoisting equipment and preventing joint deformation. High-speed railway fish plates need insulation treatment to avoid track circuit interference, and ordinary railway/industrial and mining fish plates have no insulation requirements, selected as needed. The joint spacing of high-speed railway fish plates ≤0.5mm, ordinary railway ≤1mm, industrial and mining ≤0.8mm, the smaller the spacing, the smoother the driving.
What are the common problems and rectification measures of fish plates in use?
Common problems of fish plates in use are bolt loosening, joint wear, plate deformation, crack fracture and rail joint offset, all need timely treatment to avoid potential safety hazards. Bolt loosening is caused by torque attenuation, retighten to the standard torque, install lock nuts, and regularly conduct torque detection for heavy-duty tracks to eliminate loosening. Joint wear ≥1mm, the fit gap between fish plate and rail is too large, new fish plates must be replaced immediately, and worn parts are strictly prohibited to continue using to avoid joint disconnection. Plate deformation is due to overload or skew installation, remove and correct the deformation, replace if unable to correct, and recalibrate the installation position to ensure centering. Crack fracture is due to substandard materials or impact overload, immediately replace fish plates with high-strength materials, and upgrade to Q355 type for heavy-duty lines. Rail joint offset is due to insufficient locking force, check whether the fish plate model is suitable, replace with high-strength bolts and increase the locking torque, and calibrate the rail position.