The Fishplate broken--Cause & Troubleshooting

1. Cause

(1) The material of the splint itself is poor.

(2) The maintenance of the line is poor. When the low joint of the rail is repaired, the splint is quenched to bend upward, which destroys the original physical properties of the splint and reduces the original strength.

(3) When repairing the rail joint, the tamping is poor, the rail wear at the joint of the new and old rails is inconsistent, the joint rail surface and the inner side of the working surface are staggered, and when the train passes, the impact force of the joint increases, causing the splint to break.

2. Judgment

When the splint cracks, the iron sheet will fall off first, and then the trace will occur. At this time, the mark should be clear and the monitoring should be strengthened. If there is a crack in the center of the splint, the straight and special-shaped splint is more than 5mm, the double-head and fishtail splint is more than 15mm, and the crack in other parts develops to the bolt hole or the splint is broken, timely measures shall be taken to replace it.

3. Emergency treatment of splint breaking

(1) After the splint is broken, if the rail joint does not shrink significantly, the fasteners or anti-creepers before and after the broken joint can be tightened or fastened, and then the splint can be replaced in time to make the train pass the fault location.

(2) If there is no spare splint in the local area, the broken splint can be selected and temporarily replaced on the joint through the eyelet to strengthen the joint strength, and then the train can pass slowly.

Operation procedures for replacing splints:

A. Lift the spike or loosen the gusset plate: use the spike pad to lift the spike on the inside of the joint, and insert the wood piece of the spike hole. The bolts shall be loosened at the concrete sleeper section and the gusset plate shall be rotated by 90 º.

B. Remove the bolts: remove them every other, and then remove them when returning.

C. Remove the splint: use the crowbar tip to pry out the splint and place it in a position that will not affect the replacement operation.

D. Install the clamping plate: align the clamping plate hole and the rail hole with the switch rail with screws, and then insert the bolts. When fastening the bolt holes, if the six-hole plywood is installed in the straight section, the outermost two shall be installed first, then the middle two shall be installed, and finally the other two shall be installed; In the curve section, first the outermost two, then the last two, and finally the middle two. After all bolts are tightened, tighten them again.

E. Nailing or fastening plate: according to the requirements of the nailing operation, the internal and external spikes shall be nailed. In the concrete sleeper section, the gusset plate shall be aligned and the bolts shall be installed.

F. Remove the protective signal, open the line and release the train when the equipment status meets the requirements after inspection.

4. Technical standards to be met after fishplate breaking treatment

(1) Two cleats shall be used for the rail joint to fix the bolts according to the screw holes, generally no less than 4 bolts, and then make up after the rail joint is open to traffic.

(2) According to the provisions of the Maintenance Regulations, the rail surface and the inner side are staggered, and the main line and receiving-departure line are not more than 1mm, and other station lines are not more than 2mm.

5. Measuring tools and tools required to handle splint breakage

Measuring tools required: torque wrench, universal ruler

Tools required: adjustable wrench, crowbar, spike hammer, screw handle, wire brush