Controller Inspection

IRM is now officially open for visitors on weekdays, although nothing is running and the barns are not open. And of course we don't charge admission under these circumstances. Still, there were several groups wandering around viewing the outdoor displays and enjoying the nice weather.

I started by putting a final interior coat on three 319 windows and their window shade tracks in the shop. I then turned to finishing (pretty much) inspection and lubrication on the 309, as I had brought out some Vaseline for the controllers and reversers. I still need to do the roof when I have a helper. But say, while we're here, let's take an educational look at how a controller works.

CONTROLLER STUDIES 101

This is a GE C-6 controller for type M control. Most GE models have the same general design. Note that the main drum is geared to the controller handle shaft, so it turns in the opposite direction. At the top, #1 is the reverser drum, with two contacts for forward and reverse, of course. It's mechanically interlocked to the main drum so you can't move the handle unless the reverse key is in forward or reverse, and you can't move the reverse key unless the handle is off. #2 is the spring which drives the throttle mechanism (#3). There are two sliding contacts, wired in series. The throttle can only be engaged by holding the throttle button down while the handle is moved from off to the first point. #4 is the gearing for the main drum. #5 is the star wheel which helps the motorman keep the controller in the correct position for each point. Below that is the main drum (#6) with all of the various contact fingers. The arc chute assembly has been opened, and is off to the right. Finally, #7 is the magnetic blow-out coil at the bottom of the controller.

The second picture shows the main drum advanced to about the third point.

As with all GE type M controllers, this controller switches 600 volts DC, unlike the Westinghouse electro-pneumatic system, where a dropping resistor reduces the voltage to the controller to perhaps 150V.

Any questions? OK, good. There will be a quiz on Wednesday.

I did some cleaning up in the 319. And I helped Joel for a while with the project of removing a spare bus jumper pin, which we need for the 460. We're making some progress, and we figured out what sort of custom-made tool we'll need for the job.

And while walking out to check on the 321, I found some vantage points overlooking the creek.