Monday, August 27, 2007

Milling the Slip Joints

New volunteer Harold Tilton has taken over where Dave Spohr left off when he moved to the Bay Area several months ago. Harold was "recruited" during the 2007 county fair. The retired pile driver operator brings welding, machine shop and metal fabrication skills to the railway.

Here's how Keith Berry described the restoration process last year:

Dave has been working with Sam and Dale since February 2006 to restore the male driveshaft faces to specification. Over normal locomotive operation, surface-to-surface friction from turning and the constant presence of dirt kicked up from the ballast ground the driveshaft faces down.

Sam's challenge was to locate an arbitrary starting surface point to weld/build the contact surfaces and end up with a four-sided square drive shaft. Once established, Dale welds, and Dave mills the surfaces. Then Dale welds, and Dave again mills, and around it goes. Or in this case, square it becomes! Eventually, the shaft will reach finished specification and they'll start on the next shaft.