Process for Welding Railroad Rail
Note: Tom Koehler is one of the old men of railway welding, going back maybe 60 years (on the job).
Tom, What is the process for welding rail-- the torch, tip sizes, fillers, pre-and postheats?
Dr. JJ and Kent
Tom Responds:
RR rail is a high carbon steel and subject to certain kinds of flaws from constant pounding. It is my job, then, to flush out those flaws, and repair them. In years past, we would use a large welding tip to create a puddle at the site of the flaw, watching the color of the metal. (thru goggles)
The flawed metal would show bright white, and the margin between the flaw and the sound body of metal underneath, would be "gray" probably really orange, I guess. By means of puddling, the damaged metal would be washed out of the treatment area.
Using a 1/4" diam. filler rod (type MW), the welder would proceed to weld in an ordinary manner, laying in new metal until the proper height or surface is reached. This is not left-to-right or vice-versa. This is going forwards, away from the welder, and then back again, towards the welder. The surface was forged by hammering (32oz hammer) until the welder is satisfied with the results. Final surface finish was achieved with a flatter, struck by the helper or striker and an 8# short sledge.
It was music to the ears when a well-practiced team worked together. A good striker can swing effectively either right or left handed, at any angle, keeping up with the moving flatter. (it is a two-handed grip, with either the left or right hand uppermost) Excess metal was trimmed off with a hot cut chisel (and the striker with his sledge) sometimes no grinding was needed at job's end. I always had to wear ear plugs, account of the noise from the torch. 12 to 14 pounds of acetylene, and oxygen to balance. control the heat input, so there is not too much sparking from burning carbon, use a wind screen on windy days to minimize the movement of air across the surface of the puddle (burning carbon, again)
The filler metal was some hard stuff, but it is a moot point, because we are told the mfr. will not make any more of it. The only use was track welding, and that is going electric, now. everywhere. I don't even teach gas welding anymore to the new track welder trainees.
It is just too hard to learn to "catch the puddle" using a monstrous huge torch (size 12 or 13 tip) in the right hand and a pound of filler rod in the other hand and co-ordinating the movements between the two. It is somewhat akin to rubbing your tummy and patting your head. Work on a large flaw, putting in 3 to 5 pounds of metal was almost hypnotic for the welder... very peaceful and relaxing until you try to stand up.
There is so much heat associated with a large frog welding job, that there have been times I did not even know I was on fire until my partner started pounding on my legs. After the second time, I convinced my employer that I rated a set of leather chaps, --even if I was just some track scum. Thermite welding has been used for the joining of two pieces of rail together, forming a continuous string of rail. Railroads have been doing this since about 1909 or thereabouts, I think.
Minor changes in the technology, but an old-timer would recognize what is going on and be able to take over with just a little refresher info. O large OA rosebud was used for preheating the weld site and mold. We used a pressurized gasoline/air torch forawhile, but it was too cranky and unreliable. Now we use oxy-propane for preheating. any questions... feel free to ask. Tom Koehler
I will find a way or make one. (author unknown to me)
See also:
Welding Railroad Rails - Electric welding, rod, preheat and postheat procedures
