Hi Hank,

As someone who had to use the SD's on a daily basis, the SD-50's and 60's were not really very good locomotives. The SD-60's were a good first step but that was it. They had lots of teething problems and later lots of teen and age problems.

The SD-70's were reliable and in my opinion, the modern incarnation of the SD-40's. The SD-70's could be counted on, unlike the SD-60's which were many times just along for the ride.

Of course that is just my experience over the time that the UP purchased their first SD-70's (UP ordered model SD-70M, with the "comfort" cabs) until I retired seven years ago. If any locomotive saved EMD's Bacon, I would rate it the SD-70, with UP alone purchasing 1,500 of them. There were some problems, granted, when overflow production was built in Mexico. It was traced down to not properly cleaning welding slag from installation of the blowers for the traction motors. It seems that electric motors don't like having pieces of steel air injected into them. They had a tendency to short out traction motors.... Once that was discovered and fixed, even the Mexican built units were good power.

As I said, I hope that the WP&Y finds their new diesel units to be as reliable as the SD-70's.

Rick