Stan’s Obligatory Blog

Happy Thanksgiving

2/7/2015

I always was curious how they did this…

Filed under: — stan @ 6:26 pm

On Saturday morning I went for a short bike ride with Carla. We headed east, with a plan of seeing how the yard and shops they are building on the Metro Gold Line in Monrovia were coming along. We rode out there, and we saw a crew at work putting up the overhead wires, as well as a single test train parked on the track. That was novel, since it’s the first train we’ve seen on that part of the line.

Continuing on, we passed the Azusa Rockery. Apparently, it’s an exhibit of the sorts of things they mine there in the quarry in Azusa. From there, we rode to see the downtown Azusa station that is under construction. We were going to see if we could find the ‘golden spike’ again. While we were there, a truck came by on the tracks, and they stopped just a short distance from us. The guys got out and started unloaded some serious equipment. We asked them what they were doing, and they said they were going to weld the rails together. So we figured we’d settle in and watch, since I’d always been curious to see how this is done.

They first took some wrenches and unbolted the spot where the rails were bolted together. Then they took out a big power saw and cut a little bit off the end of one rail to make about a 1/2 or 3/4 inch gap between the ends of the two rails. Then they got out what looked like some ceramic molds that they clamped around the rail joint, filling in the gaps with sand. Once all that was in place, they lit a torch and stuck it down into the space inside the mold they’d constructed around the rail joint.

While the torch was making flames come out of the top of the mold, they brought out a box of thermite. At that point, I knew we were going to see some fireworks.

After the torch had been heating the joint for a few minutes, they took it out, and then they placed a little white can that looked kind of like a big thermos on top of the mold. Then they lit it on fire. Bright yellow flames came out the top, and soon, glowing-orange molten steel was pouring out the bottom. It flowed into the mold around the rail joint and filled it up until a small amount of molten steel came out the top of the mold. I guess that was the indication that it had filled the gap between the rails.

They let the joint cool for a few minutes, and then they broke the mold off of it with sledgehammers. The metal inside was solidified, but still glowing orange. They cleaned it up a bit with a sledgehammer and a wedge. Then they got out a grinder machine that cleaned up the weld. All told, it was a pretty good pyrotechnic show.

30 miles


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