EMD Locomotive Horsepower Comparison
You’ve already experienced the 100-year history of EMD in the Century of Electro-Motive Diesel video. In continuing to celebrate the centennial, let’s compare and contrast all the different types of diesel locomotives with respect to their horsepower outputs. Electro-Motive’s first railroad motor car was propelled by a 175-horsepower gasoline engine; later EMC doodlebugs had various Winton engines producing between 225 and 400 hp. Here’s a comparison chart I created to illustrate how powerful each EMD model is as well as how many cylinders in each prime mover. As already covered in the history video, the Union Pacific M-10000 streamliner used a 12-cylinder distillate engine whereas the Burlington Zephyr used an 8-cylinder diesel engine. Both trains were rated at 600 hp but the latter’s prime mover had four cylinders fewer that the one on the former. You can infer that more powerful engines can evidently produce the same output in fewer cylinders than their less efficient predecessors.
Before viewing the comparison chart, there are a few important notes to help you understand the statistics. First of all, you will see some model names with suffixes in parentheses; this indicates one or more variants that are mechanically identical to the primary model, regardless of their body styles. For example, “SD60 (M/I/F)” means that this type includes the standard-cab SD60, the wide-cab SD60M, the isolated-cab SD60I, and the Canadian cowl-bodied SD60F, all of which are powered by the 16-cylinder 710G diesel engine rated at 3,800 hp. And second of all, you’ll notice an extra number followed by an asterisk in some table cells of the “Number of Cylinders” and “Total Horsepower” columns. This indicates the multiplication of cylinders and horsepower in each individual engine. For instance, if you see a 2 with an asterisk, it means there are two separate engines in one locomotive or even two separate locomotives in a single model. The “Model” column will tell you which types involve multiple units as a set.
To make this chart even more detailed, LaRosa’s Trains is smart enough to add the “Engine Type” column to identify the many different Electro-Motive prime movers through the years, be they two-cycle (201A, 567, 645, 710G) or four-cycle (265H, 1010J). The notation of an EMD engine model consists of the cylinder count, the main three-or-four-digit number (usually the cylinder displacement), and the letter suffix for the crankcase design. For example, the 16-645E diesel has 16 cylinders, each with a 645-cubic inch displacement, and the E series crankcase. The 567 variants range from A to D while the 645 types are between E and F. All the later Electro-Motive engine models have only a single crankcase design. Initially, some prime movers were first introduced without a letter. The original version of the Winton 201 was designed as a marine engine, but the production version (named the 201A) became suitable for railroad applications. Similarly, the early 567 diesel did not include a letter until the upgraded type (the 567A) was introduced. There is only one EMD locomotive that is not powered by any Electro-Motive engine; the F125 uses the four-cycle C175-20 manufactured by Caterpillar, which is the current owner of EMD.
Can you find the most powerful diesel locomotive? Just follow along the horsepower ratings from the top to the bottom of the chart. Here are the screenshots snipped from this document, but you can also download a PDF copy of it for a full view. Click below to download the EMD Horsepower Comparison chart. Have fun!
