FLASH BUTT WELDING
We use a mobile welding plant to weld rail tracks using the flash butt welding process. The welding head of the mobile welder pulls and aligns the two end rails. It then charges them electrically and hydraulically forges the rail ends together by melting the two parent ends. The welding head automatically shears upset metal to within 1/8" of the rail profile. Our Rail Profile Grinder then removes the 1/8" flashing material from the rail. This leaves a smooth base and greatly reduces the likelihood of stress risers, which shorten the life of the rail. The sides and head of the rail are also ground to the profile of the parent rail. Once the welding is complete we test the joint for hardness, ultrasonic flaws and acceptable stress.
Flash Butt welding has a few advantages over Thermit welding. It is much faster with the capability of performing about 10 welds in one hour. It only requires one operator for the welding operation. It has a slightly higher level of consistency from weld to weld. However, Thermit welds can be performed under a wide variety of traffic and climactic conditions unlike Flash Butt welding, which requires a longer block time. Flash Butt welding is also more popular for welding new rails whereas Thermit welding is great for both new and used rails. Depending on the above mentioned factors, we can execute welding with either technique for our clients.