Development of an advanced ultrasonic inspection tool for rapid volumetric examination of aluminothermic rail welds

There are millions of aluminothermic field welds on Europe's rail network. Occasionally flaws develop during and shortly after welding that can lead to early failure and this can cause train derailment, disruption to train services and costs to the rail network, train operating companies and maintenance operators. The welds are made as a casting and are more difficult to inspect than joints made by other welding processes. The inspection tool, Railect, was developed to provide quick and easy inspection of the full weld body. The latest prototype is more robust, easier to deploy, and more importantly compatible with 4 types of rail profile, including 56E1, 54E1, 54E2, and 60E1. The first three are widely used in European rail industry, which allows the product to penetrate the European market. This paper presents the operations of the inspection tool and shows how it has been made compatible with different profiles. Once deployed, defects on the head, web, and foot can be picked up by different sensors within a minute. Comparison trials are also described. In the recent trial, it has also been demonstrated Railect can easily detect foot flaws that were often missed by conventional UT.