An EMC builders photo of the Missouri Pacific's AA No. 7100.

(Electro-Motive Corporation, CS Archives, W. Lenheim Collection)


Delta Eagle drumhead.


Delta Eagle passenger train redirects here.

AA was a designator used for several different diesel locomotive types custom built by General Motors Corporation EMC/GM with passenger or baggage space in the same body. This locomotive is listed as class AA-6 by R. Craig, and the designation is logical as the locomotive is described as "half an E6" in the Second Diesel Spotter's Guide.

One such was a single locomotive built for the Missouri Pacific Railroad, delivered in August 1940, numbered No. 7100. MP 7100 was built for service with the Delta Eagle passenger train, which ran between Memphis, Tennessee and Tallulah, Louisiana. Note: Missouri Pacific ordered all their 'E' units with portholes instead of square windows like most of the E series from the EA to E7's. This was the only MoPac unit with square windows (on the baggage door).

Since the two-car train the unit would have to haul was comparatively light, the AA was built with only one 1,000 hp EMD 567 V12 prime mover, and a baggage compartment where the second diesel would have been.

Other EMC/GM locomotives carrying the AA classification include the Pioneer Zephyr, Flying Yankee, and General Pershing Zephyr power units.


EMC AA Overview

Type and origin
Power type: Diesel-electric
Builder: General Motors Corporation (EMC/GM)
Build date: August 1940
Total produced: 1
​• AAR A1A-3
Gauge: 4 ft 8+1⁄2 in (1,435 mm)
Adhesive weight: 97,700 lb (44,316.0 kilograms)
Locomotive weight: 247,340 lb (112,191.5 kilograms)
Fuel capacity: 1,200 US gal (4,500 L; 1,000 imp gal)
Prime mover: EMD 567
Engine type: V12 diesel
Cylinders: 12
Performance figures
Maximum speed: 98 mph (158 km/h)
Power output: 1,000 hp (746 kW)
Tractive effort: 24,425 lbf (108.65 kN) at 34 mph (55 km/h)
Operator: Missouri Pacific Railroad
Road Number: 7100
Retired: 1962
Disposition: Scrapped