I recently received my copy of the Southern Pacific Ten-Coupled Locomotives book. Like my other SP steam locomotive books by Robert Church it is full of information and data about the Southern Pacific ten-coupled steam locomotives.
Now I just read the chapter on the Baldwin 60000 and I found the Mr. Church fell into some of the same errors that others have stated about the Baldwin 60000. First is that the 60000 had triple Walschaerts valve gear (This arrangement was used on the Baldwin-built D&RGW M-75 class 4-8-2 and UP's "Baldface Nine rebuilds of some of their UP-2 class 4-12-2). On the 60000 what Baldwin did was far more creative. They used the Walschaerts valve gear on the engineers side to operate the valve on the center high pressure cylinder. They used the Walschaerts valve gear on the fireman's side to operate the left low pressure cylinder, and from the left crosshead they used a lever like that used in Young valve gear to operate the right low pressure cylinder. This use of a Young valve gear setup is why the cranks on the drivers had to be set to 90 degrees, with the center crank set 135 degrees apart from the other two.
Another issue is the claim that part of the failure of the 6000 was that it was too heavy. One page 223 Mr. Church states that the 60000 weighed 15,500 lbs more than the SP-1 class 4-10-2. But here's the part I take issue with. One page 198 he posted the data sheet for the SP-1 class engine, and on page 216 he has the data sheet for the 60000. Below are the respective weights of the two designs.
Weight SP-1 60000
On Drivers 316,000 318,000
Front Truck 65,500 66,000
Trailing Truck 60,500 61,000
Total Engine 442,000 445,000
So the actual weight difference was negligible.
What probably doomed the 60000 was that it was too different. The combination of being a compound engine in the mid 1920's along with the water tube firebox made it too radial for mose railroads.
Stuart
