Part 11: Wheels, bearings and frames—May 2001

PRRPS member Mick Ewer cleans one of NM25's driving wheel sets
PRRPS members John Lyas, Bryan Homann, and Jeff Flint pouring white metal in a tender bogie bearing for NM25

Wheels

The driving wheel sets have now come back from having the crank pin holes requartered on a large horizontal boring machine. The quartering was found to be at some variance between wheel sets before boring. They are now supposed to be within a couple of "thou of an inch" of each other both radially and angularly. The wheels are now being cleaned, and below the muck, have revealed Thompsons of Castlemaine cast into the inside of the rim.

Bearings

White metalling has also been proceeding, with all the tender and pony truck brasses having been now re-metalled. Next step is to bore these to size and fit them to the journals.

Frames

The order has been placed for machining and welding the new frame together. Completion is anticipated toward the end of June.

The stress analysis drawings previously available here are now on the next page.

Cylinder update

As of 11 May, the core boxes for the cylinder pattern are now complete. The styrene foam model of the internal coring shown in one of our photos has now been adorned with the external sand shapes to assist the moulders with the jig saw puzzle. Building the moulds should commence in Mid May.