EMD E-unit

These had similar power and mechanical layouts to the E-units, but in boxcab bodies on AAR type B two-axle trucks.

This had similar carbody styling, but otherwise had more in common with UP M-10001, M-10002, and M-10003 to M-10006, in that it was a 1,200 hp (900 kW), single-engined unit on B-B trucks instead of the E-units' A1A-A1A wheel arrangement.

Their twin V-12 diesel engine layout, Blomberg A-1-A trucks, and 57 ft 1 in (17.40 m) wheelbase would become the standard for all future E models.

The E5 designation was used for Chicago Burlington and Quincy's stainless steel clad locomotives in keeping with their Zephyr theme.

They both used the same body style, with a grille along the top of the sides the length of the loco, and several "porthole" windows below it.

Model descriptions are as originally built; EMC/EMD locomotives are often rebuilt to newer standards.

[1][2][3] While there were some cosmetic differences between E-unit models, the major line of development was technological, and largely that of increasing power.

While this engine represented a breakthrough in power-to-weight ratios and output flexibility for Diesel engines, it was a compromise between marine and locomotive requirements and wasn't well suited to the sustained full throttle operation often needed in railroad service.

The 567 model had been developed by EMD specifically for locomotive use, and exhibited excellent performance and reliability in high speed passenger train service.

The E8 used the more advanced 567B unit, with improved exhaust manifolds and other enhancements to give 1,125 hp each.

All E-units used the same EMD passenger truck design by engineer Martin Blomberg.

Two direct current generators powered four traction motors, two on each truck, in an A1A-A1A arrangement.

The E8 introduced the one-piece stamped Farr stainless-steel side grilles that made a continuous band from front to rear just below the roof, but these were often retrofitted to earlier units.

The E8, for example, was the first model to incorporate electric cooling fans, and offer dynamic braking as an option.