Edit post

Edit your reply below.

Post Body
Enter your post below.
Now I seem to recall a Trains article back in the 70s about this -- might have been written by Charles Mizell. I never paid much attention to it back then, being a callow youth, but now I guess I'll have to find it and reread it. This is what I saw in another forum in response to a question about overhaul intervals: Jack Wheelihan said: "At a really big back shop such as Altoona, West Burlington, Roanoke, Cheyenne, etc., it generally depended on the "class" of overhaul that an engine required. Such as a standard five year jacket & lagging ICC (now FRA) inspection, which also received new (or safe-ended) tubes, superheaters, running gear work, the time frame was only 1 to 2 weeks. A 15-year overhaul (10 years on an oil burning locomotive) would require a new fire box and possibly extensive boiler modifications/up-grades, and could take 3 to 4 weeks." Rich Melvin elaborated: "The thermal stresses in an oil burner's firebox are much greater than those in a coal burner. That big oil flame can be completely cut off instantly, which can allow the overall temperature in the firebox to change drastically in a very short period of time. By the same token, the flame can be brought back up to full intensity in a matter of seconds, raising the temperature quickly. "On a coal burner, you have that bed of hot coals acting as a huge thermal sink and preventing any rapid changes in firebox temperature. Sure, you can stop the stoker and cut off the supply of coal to the fire, but that huge bed of burning coals acts to slow down any temperature drop and it happens very slowly. In an oil burner, the only thermal sink available is the firebrick around the firebox, and its mass and heat absorption value are nowhere near that of a hot bed of burning coal. Thus the thermal stresses set up in a coal burner's firebox are much less than those of an oil burner. This means fewer broken staybolts, cracked sheets, checks in knuckle sheets, etc." dre, I would bet that in a central power station, the operators aren't so cavalier about turning the fuel flow on and off. Of course, on a railroad, the economic penalty for not doing this (extra fuel consumption) greatly outweighs the economic benefit (longer maintenance intervals). OS
Tags (Optional)
Tags are keywords that get attached to your post. They are used to categorize your submission and make it easier to search for. To add tags to your post type a tag into the box below and click the "Add Tag" button.
Add Tag