It was raining off and on all day, so keeping anything dry required some effort. We had visitors coming to ride the Happy Holidays train, which is good, but many of them were carrying umbrellas that seemed rather incongruous. What can you do?
With painting out of the question, I spent most of the day stripping paint. All of the large areas of the old green paint on the 36 are now gone, which is very satisfying. There are lots of little places that need to be processed, perhaps another day's work or so, but this tiresome job is nearly complete. Whew!I'm sure you're bored with this, however, so what were other people doing?
Recognize this man? Probably not, because he's wearing all the proper protective gear: goggles, respirator, ear muffs, and gloves. Our volunteers' safety is important! Anyway, this is Ray Pollice using a wire wheel to clean up part of one of the woodworking machine. This is hard, unglamorous work, but the results are worth it.
And this is a template Tim Peters was making for the end platform on the 1024. It's marked with the locations of all the holes that will need to be drilled in the replacement wooden buffer. I went through a similar process when replacing one end on the 308. Because the car is slightly more than 8' wide, a piece has to be patched onto one end, as indicated by the Jorgenson clamp at the end nearest the camera.
Finally, here's something that I found quite interesting. Our electric cars use lots of these 30A or so cartridge fuses for 600V DC. Recently, Joel noticed that one of the fuses for the heaters in the 749 was emitting steam! When the fuse was taken apart, it looked like this:
DC cartridge fuses are filled with a flame-retardent powder so that if the fuse opens, a chemical reaction will extinguish the arc. The powder burns up and you are left with a small amount of ash in the cartridge. In this case, however, the seal was bad so the powder had absorbed moisture from the air. And when the fuse melted, the wet powder continued to conduct electricity, although it heated up and started to produce steam. The arrow points to part of the ribbon fuse itself. Fuses designed for AC don't need this chemical, because the current passes through zero every half cycle, and arcs tend to extinguish themselves much faster.
As a practical matter, I don't think there's much that operating crews can do about this. It seems like a very unusual situation -- I'd never encountered it, and I've blown out several fuses over the years. Just don't store your spare fuses under water. Anyway, there's your physics lesson for today. And this will probably be on the next test, too!
