MSTS - Addon - SLI Union Pacific DDA40DX Centennial Trainset

SLI Union Pacific DD40AX Centennial Trainset

The DDA40X Centennial, also affectionately known as “Big Jack”, is one of the most recognized diesel locomotives in North American railroad history. Beginning in 1969 through 1971, the Electro-Motive Division of General Motors (EMD) produced 47 DDA40X locomotives for the Union Pacific Railroad. The UP had a history of experimenting with large locomotives, specifically, the DDA40X, Big Blow Turbines, and the 4-8-8-4 “Big Boy” steam locomotive. The Big Jack would be the last of its kind.

The DDA40X was designed for high speed freight service. The gearing allowed it to operate at speeds of up to 90 mph. These 6600 HP locomotives were commonly matched with newly acquired EMD SD40-2 “Fast Forties” into what was referred to as a “Fast Forty Sandwich”, with an SD40-2 spliced between two DDA40X locomotives. Throughout the late 1970’s, this was the locomotive consist of choice for high speed priority trains on the Union Pacific, in particular the Overland Mail trains from Chicago to Los Angeles, San Francisco, and the Pacific Northwest. The SD40-2 “Fast Forties” were built with high speed gearing specifically so they could interoperate with the DDA40X units. The DDA40X locomotives were so efficient that, despite only being in service approximately 10 years, they had generated over 2 million revenue miles each.

The DDA40X remained in service until 1980, when the entire fleet was put in storage during an economic slowdown in the industry. When traffic increased in 1984-85, 25 of the DDA40X units were put back into mainline service, but their return would be short lived. By 1986, the entire fleet was retired, however, many of the locomotives have been preserved so that future generations may marvel at the sheer size of these beasts. At the time they were built, they were the World’s largest land machines. UP 6936 is the only DDA40X in operation today. It is part of the Union Pacific heritage fleet, and it is often at the head end of Union Pacific company trains.

This product includes two DDA40X locomotives, one SD40-2 (“Fast Forty”), a consist of TOFC flat cars, and a Union Pacific CA-10 caboose. The CA-10 series were built in 1975 by International Car, and they were the last cupola cabooses delivered to the Union Pacific.


Product Features

2 Union Pacific DDA40X Centennials (# 6924 and # 6946)
1 Union Pacific SD40-2 "Fast Forty" (# 8072)
BSC 89' TOFC flat cars with 45' trailer loads (3 loads, 1 empty)
Union Pacific CA-10 Caboose (# 25735)
Daytime and Nightime Cabviews
High Quality 22khz Audio
Ready to Run TOFC Consist