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We had a good work history weekend and lots of work was done on 1364. Previously we did a hydro test earlier in the month and found some new leaks. We quickly repaired these leaks and were confident enough to take it to 250 psi.. This revealed some new leaks. Still have 1 problem with a washout plug that will need more work. Over all it was good. This last test brought us closer to FRA hydro. This weekend we will do some grinding, repair a leaking stud, and center drill some stay bolts. The washout plugs that had leaked before were removed, holes taped and plugs wrapped with Blue Seal tape and put back in and did not leak. As per Dave Pankey
The unusual winter has plagued us and made it difficult to do much work on anything. A hydrotest was suggested in the second week of March weather permitting. In prep for the hydrotest Dave Pankey opened a valve to the boiler and found that there was a small amount of air pressure present. This is quite encouraging according to Andy Breeding, as the pressure had been in there over a week. As cold weather hampers hydrotesting, if we get a warm day, like above freezing, we will try to to pull it off.
A leaking staybolt under a hydrotest
JANUARY 2019 REPORT
The operating pressure of the 1364 boiler is 200 psi. According to Federal Railway Administration any boiler operating over 15 psi must be certified with a hydrostatic test. The test for the 1364 requires us to fill the boiler with water, heating it to 70 degrees F following which the boiler is externally pressurized to 250 psi., 25% above normal operating pressure. Any potential leak show itself as a dribble of water. This detection process is much safer than steaming it to the same pressure. Once we are convinced there are no leaks, the Federal Railway Administration is called in to witness a retest and certify our inspection. Incidentally the Northern Pacific maintenance records document hydrotesting every 3 months when the locomotive was in daily service.
Presently leaks documented from previous hydrotests are being repaired. When we are satisfied with our testing we can then proceed to the next step. Once FRA certified we can then install the superheater tubes, compound compressor, and other parts that had to be removed to visualize the boiler during hydrotesting . As everyone was involved in Toy Train Christmas there was only a little bit of work done in December.
In January 2 more staybolts were replaced. Because of the expense of filling the boiler with water, we pre-check with air pressure. Once we are satisfied with air inspection we will conduct another hydrotest.
There have been alot of questions about what is a "staybolt". To the left is a picture of the inside of a boiler looking toward the firebox. The picture was taken before we reinstalled the new firetubes. A white arrow on the left points to a stabolt. The majority of the boiler is cylindrical, a naturally strong shape, but there are also some flat and irregular surfaces within the boiler too, especially around the firebox. With the intense pressures up to 200 psi inside 1364’s boiler, these surfaces would weaken, bow, and eventually buckle without staybolts to support them. Because of expansion and contraction due to temperature differences it is possible for a staybolt to break. The stabolt is hollow with a very small bore through the center. In the event that a stabolt breaks steam will leak through the small tube. This is called a "tell-tale".