After months without more than a mention about General Motor's Electro-Motive Division prototype SD70ACE locomotives, GMDX 72 and 73, the units are going beyond testing.

Since their release from GMLG's London, Ontario plant late last year, the SD70ACE prototypes have been undergoing grueling tests in Colorado. The Transportation Test Center in Pueblo has put the units through a variety of speed and durability tests, not to mention additional safety tests. They also made it to the higher elevations of Colorado for high-altitude testing, but now they are heading to the Midwest.

The units were handed over to BNSF for delivery to the Kansas City Southern n Kansas City, Missouri, later this week. The units are to find work in dedicated helper service tests on the KCS, who is further evaluating locomotive needs for the future.

Interestingly, EMD has announced that their Tier II emissions-compliant DC model being placed on the market will be known as the SD70M-2 (correct - Dash 2!). The SD70M-2 will replace all other six-axle DC freight locomotives in the EMD catalog.

Like the SD70ACe, it too will contain GM's 16-cylinder 710G prime mover rated at 4300 HP. Basically, the SD70M-2 looks similar to the SD90MAC-H with the Phase II cab as worn by the late UP SD90MAC-Hs and CP's SD90MAC-Hs. However, they are slightly shorter and do have a few other design differences. Both models contain GM's 16-cylinder 710G prime mover rated at 4300 HP.

There are currently no demonstrators of this model.