CHENNAI: The rails on the Arakkonam-Mahendrawadi section of Southern Railway, where 11 coaches of the Muzzafarpur-Yeshwantpur Express derailed on April 10, were welded together using a technique considered the best. But this is not foolproof. One person was killed and 32 injured in the April 10 accident.
A study by the Research Designs and Standards Organisation (RDSO), which develops safe and cost-effective technology, has revealed that “about 50% of weld-failure incidents are attributed to poor quality of execution at the site.” A large number of welders in zonal railways don’t have competency certificates and carry out short cuts to complete a job quickly to open a line for traffic.
The Alumino-Thermic welding technique is quick and supposed to minimize the time needed to block traffic.
Sources said the chances of such situations occurring in Southern Railway were high because most of the trunk routes were busy stretches where prolonged traffic blocks would lead to disruption of services. Hence, “tracks are welded together using AT welds and engineers keep on monitoring the joints frequently,” said a senior official.
The wear and tear of tracks increases when heavy trains are operated at top speeds. Under pressure to move more freight, the railways has increased axle load of goods trains from 20.32 tonnes to 22.82 tonnes. Speed of passenger trains has gone up to nearly 160kmph.
All these put pressure on rail joints and weld joints. The Muzzaffarpur-Yeshwantpur Express was travelling at 103kmph when a rail weld failed and coaches derailed.
The RDSO studied AT weld failures reported over three years and found that the process used to do the welding was not good and had resulted in accidents. And railway engineers have been debating the technique to minimize risks at various seminars.
Three RDSO officials who presented a paper at one such seminar say AT welds have inherent weaknesses because of the welding technique. “Efforts are on to reduce the number of such welds by using other technologies like rolling longer rails, carrying out flash butt welding,” says the paper.