[AT] OT butt welding was tractor hauling truck

[James Peck]

Is the welding supply using semiconductors to regulate the welding current? The steel mill used water cooled ignitron tubes to butt weld the leading edge of the steel strip being cold rolled to the tail of  last piece thru.

Howard Pletcher AT List Member AT List Member (mailto:hrpletch at gmail.com); For reference, I recently had a tour of the Steel Dynamics railroad rail welding facility where they weld shorter segments into 1/4 mile long rails. They apply 1000 amps for about 2 seconds to fuse the rails together.   It would take something larger to handle 48,000 amps.