Machinist Tom Weisner and his assistant Dale Birkholz are setting up the Underwood boring bar on the fireman's side valve, while Don Wheeler, PRPA President, looks on. Photo by Terry Thompson

Machinist Tom Weisner setting up the Underwood boring bar on the fireman's side valve. Photo by Dale Birkholz

Aligning the bar. Photo by Dale Birkholz

Aligning the bar to the exact center line of the cylinder. Photo by Dale Birkholz

Cutting tool. Dark area is surface yet to be machined. Photo by Dale Birkholz

Underwood boring bar in operation. Photo by Dale Birkholz

View through the left valve looking forward. Dark spots on near seat are witness marks. Photo by Dale Birkholz

Aligning the boring bar with dial indicator. Photo by Terry Thompson

Machinist Tom Weisner (left), assisted by Dale Birkholz, setting up to bore the valve cylinder on the engineer's side. Photo by Terry Thompson