December 8, 2008

Installing new TIRES and then quartering & burnishing the crank pins.

Installing tires onto a driver center is not a common task in this century.  ASTA's 786 has all new tires for the drivers.  It is important that each driver's outside diameter be exactly the same, that each crank pin be exactly the same distance from the center line of the axle and that the opposing crankpins on each axle be at exactly 90 degrees.  The, each crank pin is burnished to increase the surface hardness and give it a good service life.

The machining process to assure the crankpins are in the precise location is called "quartering".  There are only a few machines remaining in in the world capable of performing this machining operation with good accuracy.  One set of those machines is located at the Tennessee Valley Railroad in Chattanooga, TN where the work is being done under the management of the Steam Operations Corporation

 

David Pugh applying tire to wheel center.

A "ring of fire" is arranged on the circumference of the tire.  The tire is heated to expand it so that it can be insalled over the machined "center" of the driving wheel.

 


Photo: Steam Operations Corporation
new tire being applied to wheel center.
Photo: Steam Operations Corporation
Applying tires to 786 wheel centers.
Photo: David Pugh TVRM/SOC
 
Photo: Pat Powers
 
Photo: Pat Powers
 
Photo: Pat Powers

Photo: Pat Powers
 
Photo: Pat Powers
 
Photo: Pat Powers
 
Photo: Pat Powers
 
Photo: Pat Powers
 
Photo: Pat Powers
 
Photo: Pat Powers
R-2 crank pin prior to quartering.
 
 

 


Photo: Steam Operations Corporation
Machining R-2 crank pin on quarter.

 


Photo: Steam Operations Corporation
Burnish rolling the finish on R-2 crank pin. The rolling work hardens to help resist scoring from road dirt the surface and provides a smooth finish for the rod brass,
Photo: Steam Operations Corporation
burnish rolling R-2
Photo: Steam Operations Corporation
TVRM's Doug Karhan moving #2 wheel set after applying new tires and quartering.
 

Photo: Steam Operations Corporation
 

The completed drivers have now been delivered to Steam Operations Corporation in Muscle Shoals, AL where they will be stored unti time to assemble them to the 786 frame.