Monday, July 25, 2022

Inspection Day

Frank writes...


Sunday was a warm one, though not as hot as Saturday. When I arrived mid-afternoon, Nick, Nathan, and Mikey were already working on switching the 1754 off the pit and getting the 319 ready to bring over. It's inspection time!
I didn't take too many photos, but the work wasn't very photogenic. We got the brakes adjusted, motors and trucks checked out, and contactors checked. One thing we wanted to take a look at was why the contactors don't sequence in parallel. We don't need the parallel steps, but something's amiss that's preventing the parallel sequence from working.
You will notice in this "as observed" sequence chart I drew up that something is amiss once you get past the fifth point. In parallel we're only getting "resistance" contactors picking up. Nothing at all picks up in the sixth point, and the ninth point doesn't pick up an extra contactor like it's supposed to. We ruled out a couple of potential issues but didn't track down the root cause of the problem. Fortunately, the car works fine in series, and that's all we need for our operation. Many thanks to Nick, Mikey, Nathan, and Greg for all of their help with this!
UPDATE: My father has helpfully provided the *correct* sequence chart for the 319, which is to say, how it's supposed to work. This was created years ago for the 321, which has the exact same control system.
His father adds: I can identify the function of each of the contactors, although they're in a non-standard order, but that's not necessary.  On the first point of parallel, contactors 1, 3, 4, 5, and 6 should come up, and these five actuating coils are in series.  The most probable cause of failure, I would think, is that either a coil is burned out, a connection is broken, or an interlock is open.  (And 4 and 5, T1 and T2, are working.)  That narrows it down.  Note that if those contactors don't come up, the accelerating circuits cannot possibly work correctly due to the series vs parallel interlocks.  So the other contactors, 7 through 13, may well be OK.
In the meantime, the guys brought the 1754 back onto the pit lead on top of the 319 to continue with its annual inspection. Here we see Zach up on the roof adjusting the spring tension on the trolley bases. Nick also spent a while lapping one of the car's brake valves; this particular valve (an M23) is intermittently dynamiting the car when a service application is taken. The problem doesn't occur from the other end, so it's presumably the motorman's valve. By the end of the day more lapping was still needed, but Nick, Matt, and Mikey helped move the 1754 and then wye the 319 before putting the latter car back in Barn 8. Right now the tentative plan is to run two three-car wood trains (one CA&E and one CRT) for the Vintage Transport Extravaganza along with two steam engines and maybe even the Zephyr. Tell your friends - you won't want to miss it!

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