Railroad Trains for the Soul - Union Pacific DDA40X Centennials

The answer to yesterday’s blog post is the Union Pacific DDA40X Centennial, the king of all EMD locomotives! As you’ve seen at the bottom of the horsepower comparison chart, this diesel giant has two 16-645E engines, each producing 3,300 hp. This is actually 300 horses more than the standard 16-cylinder 645 used for the GP40 and SD40 models. According to Brian Solomon’s GE and EMD Locomotives book, the extra power comes from the prime mover’s increased maximum rpm level and compression ratio. Without those boosts, the DD40 could have been rated at 6,000 hp, which would be equally as powerful as the single-engined SD90MAC-H.

Here are two separate videos for the best illustration of the Centennials thundering on the rails. The first shows them in action during their careers on the UP and you’ll also see one being formally donated to the Feather River Railroad Museum. The other video gives you an extremely detailed tour around a DD40 number 6922 preserved in North Platte, Nebraska. You’ll learn how this massive beast works by taking a look inside the cab, the electrical compartment, and the double engine room. While there are a few major components unique to the DD40, most of the equipment can be seen in a typical EMD locomotive, not only the 645 engines but also the electronic Dash-2 modules that were introduced in this particular model. Everything about the Centennial is just fascinating and it’s all explained in the informal 100-minute familiarization video.