Re: 315's new "Economy" firebox doors

To all the guys working on the 315 project:

Seeing the photo of the Economy fire doors set up on their test stand reminded me of a similar project we did to restore the 497 to service on the D&S. Castings for the door halves and possibly the air actuator cylinder were procured, but just about all the rest of the arms, links and levers were nicely fabricated by our steel man, Weldon Queen. I was tasked with machining the pins, bushings and miscellaneous parts and assembling/testing the unit. I made up a temporary test stand on one of the steel work benches in the roundhouse, setting it as close to the angle off vertical as it would be when mounted on 497's backhead. Having had considerable experience with the lop-sided and uneven closing of the K28 fire doors, I decided the 497's doors were going to work perfectly. I think I may have been in my "aircraft tolerance" phase at that time. Anyway, I got all the pins and bushings made and assembled and adjusted the doors. I got a wicked cut on my finger while making a measurement for comparison purposes on 473's doors and was ever so careful from that time on when working with the doors--when the balance arm is disconnected those doors get real heavy. After numerous assemblies/disassemblies and testing, I got the doors working really nicely--opening promptly but at a controlled speed, and closing smoothly and quietly--sweet! This must have been in the fall because I left to go back to sea before the doors were installed and the engine was test-fired a month or two later. It's just as well I was safely at sea, because when the engine was fired up and the door assembly got hot, it ceased working. A by-then familiar cry was heard--"Where's Yeamans?" Seems we had a similar event with the 497's new throttle that I built. In the end, the doors had to be partially disassembled and the aircraft tolerances modified to railroad tolerances. That got the doors working again and ready for the road. So, I hope you've left adequate clearance on all your pivot pins and bushings. The 315 looks fantastic--what a great project! Good luck on the fireup and testing.