The initial selection process that was used to pick the five motors was flawed. It used a torque prediction with no load. Recent tests have shown that the loaded motor torques do not follow that ranking.
These tests have shown that the motor capability differences is not the largest contributor to maximum train length.
These impacts are as follows:
- the wheel material and size has been shown to impact the train length by a factor of more than two.
- The number of drive axles increase the train length by a 1.5 factor between B-B & C-C trucks. The C-C yields the longest train.
- the good motors seem to impact the train length by around 20 percent.
- Engine weight appears to the improve the train length around 25 percent. At most. The manufacturer’s have used almost all available weight adders because it was easy to add weight.
- the frame design data does not show a large impact. 3 to 4 percent. Currently it favors the inside frame, but it could easily swing to the outside frame.
As indicated earlier, using a derivative approach the motor rankings have been scrambled. The intention is to examine the best five or six motors on five engines to demonstrate the best combination on each engine. This will include the best wheel material & size. The intent is to show the large draw bar force results and the corresponding large train lengths. A goal of 250 grams of draw bar force and a train length of 60 cars on a 2.5 percent grade should be demonstrated In this process.
more to come
