UNION PACIFIC 4564 ON THE FLYOVER, CIENEGA CREEK, ARIZONA In Monochrome

This black and white photograph captures Union Pacific locomotives crossing the high steel bridge over Cienega Creek east of Tucson, Arizona. The... more

by Douglas Taylor

Title

UNION PACIFIC 4564 ON THE FLYOVER, CIENEGA CREEK, ARIZONA In Monochrome

Artist

Douglas Taylor

Medium

Photograph - Fine Art Digital Photography

Description

This black and white photograph captures Union Pacific locomotives crossing the high steel bridge over Cienega Creek east of Tucson, Arizona. The strong contrast emphasizes the metallic textures and structural details of the locomotive and the bridge against a clear sky.

Union Pacific 4564 is the lead locomotive of a trio pulling a miles-long westbound freight train in early morning light on the flyover at Cienega Creek where it also crosses the eastbound tracks down in the canyon below. This Model SD70M locomotive was manufactured by Electro-Motive Diesel at London, Ontario, Canada in 2002.

The pulling power of this locomotive is provided by a huge, 11,360 cubic inch V-16 diesel producing 4,000 horsepower which drives direct-current electric traction motors. Each monster weighs an astonishing 415,000 pounds and is over 73 feet long. All that mass is required for traction on the steel rails in inclement weather and for keeping the drive wheels rolling on steep grades. The traction motors are capable of generating an astonishing 175,500 foot/pounds of torque!

The SD70M was an advanced design and featured the unique HTCR truck (high-traction, six-axle, radial) which will steer itself into oncoming curves instead of just following the rail which greatly reduced wear to both rail and truck/axle components.

Not surprisingly railroads absolutely loved such a feature, which perhaps more than other reason made the SD70 series so successful. Union Pacific appreciated this feature so much that they bought 1,429 of these locomotives. An even more powerful evolution of this type, the SD70ACe went into production in 2004 and has AC drive motors, along with meeting stringent emissions regulations. More than 1,000 of these have been produced.

Uploaded

March 7th, 2024