Throughout history — when better, more cost effective solutions are found — changes are quickly embraced by businesses. So it is reasonable to ask why railroads took over 30 years to replace their steam locomotives with diesels.

The answers lie with both circumstances the railroads controlled and a world event which they did not.

From the mid-1800s until the late 1930s, the steam locomotive reigned supreme as the most reliable, cost effective, safe and expeditious way to move goods and people throughout the states and across the nation. In fact, the United States became united, coast to coast, because of railroads and steam locomotives.

From the mid-1920s to late 1940s, the steam locomotive was refined into a machine capable of sustaining speeds of 100 mph for passenger service, as well as being able to pull freight trains in excess of 10,000 tons.

While steam locomotives moved the nation’s goods and passengers, in 1925 the first successful diesel-electric locomotive was constructed by the consortium of the American Locomotive Company (Alco), General Electric and Ingersoll-Rand corporations. This invention paved the way for locomotives to use a diesel engine to spin a large generator, which provided electricity to power electric motors connected to the wheels by gears.

While only producing 300 horsepower at a time when steam locomotives were producing 2,000 horsepower or more, this diesel locomotive showed the railroads that internal combustion technology could be utilized, at least for yard switching duties a where a limited number of railcars were moved at a time, at low speed.

Various locomotive builders joined in making similar types of diesel switcher locomotives throughout the 1930s, with horsepower ratings as high as 1,000.

Railroad management was still convinced, however, that only steam locomotives, which were now capable of producing in excess of 4,000 horsepower, had the power, ruggedness and reliability to withstand the high speeds and heavy loads of trains operated out on the main lines.

In 1939, the debut of the FT Model diesel by EMD (a division of General Motors), changed this thinking virtually overnight. By taking two separate 1,350 horsepower diesel locomotives, one with a cab and controls for the crew known as the A-unit and a non-cab crewless B-unit, and permanently coupling them together, a 2,700 horsepower A-B set was formed.

By coupling a pair of these A-B sets back to back, a 5,400 horsepower four unit diesel locomotive A-B-B-A consist could now pull heavy trains as quickly as the most modern of steam locomotives.

In a stroke of marketing brilliance, a demonstrator 5,400 horsepower A-B-B-A consist of FT Model diesels successfully traveled 83,764 miles across 20 states. The trip proved that this more cost effective form of power could indeed provide enough horsepower and speed, as well as withstand the rigors of the days main line railroading demands.

With this new motive power technology firmly in place as the future of railroading, it would seem that throughout the 1940s railroad’s locomotives would be changing over from steam to diesel technology rapidly. This would have probably happened if it weren’t for one event — the outbreak of World War II, and America’s direct involvement in 1941.

Shortly after the bombing of Pearl Harbor in January 1942, the U.S. Government created the War Production Board. The agency supervised wartime production and allocations, including that of railroad locomotives.

While the FT demonstrator diesel had proven itself to the railroads, with America at war, the War Production Board was now allocating diesel engines that could have powered locomotives to other uses. Additionally, the railroads were required, for the most part, to purchase locomotives of past proven designs, or to rebuild locomotives that they already had.

Since steam locomotives were proven technology as well as the vast majority of the locomotives still in use on railroads in 1942, it was mostly steam locomotives that would be continually built, or rebuilt, throughout the war.

The 1930s into the late 1940s were a very busy time for America’s three major steam locomotive builders of Alco, Baldwin, and Lima, as well as some railroads that designed and constructed their own locomotives.

These locomotive building facilities assigned their best design teams and most brilliant engineers to create and construct steam locomotives in an attempt to outperform the new diesels. These new steam locomotives grew to lengths in excess of 130 feet, weighed over 1 million pounds, and could produce upward of 8,000 horsepower, with some passenger models unofficially obtaining speeds in excess of 120 mph.

For railroads that were not allocated new steam or diesel locomotives during the war, but were allowed to rebuild locomotives that they had, they, at times, took the word rebuild as “rebuild into what we need today.”

One of the most successful of these locomotive rebuild/conversions happened at the Reading Railroad. Most of the Reading Railroad’s fleet of freight steam locomotives dated back to a time when most freight trains operated between 25 mph to 35 mph, with locomotives that had a maximum speed of 50 mph. With the outbreak of the war, the Reading found itself in need of locomotives that could pull freight trains at speeds up to 70 mph.

Steam locomotives are classified by how many wheels they have in total, broken down by how many are in front of the main driver wheels, how many main driver wheels there are connected by rods providing the power to move the train, and how many wheels there are under the firebox.

The Reading had an abundance of 2-8-0 steam locomotives, equipped with very large fireboxes. The Reading Railroad, in conjunction with the Baldwin Locomotive Works, engineered and designed the rebuilding of these smaller 2-8-0 locomotives into upgraded, larger 4-8-4 steam locomotives, and were given a new classification of “T1.”

The T1 locomotives had their powered main driver wheels enlarged to 70 inches, with their weight increasing to over 400 tons. The length grew to slightly longer than 110 feet including the tender car that held 26 tons of coal and 19,000 gallons of water. Top speed was increased to 70mph, and they were capable of pulling 12,000 tons on level track. The 30 “new” 5,000 horsepower Reading T1 4-8-4 steam locomotive rebuilds constructed between 1945 and 1947 outperformed the smaller 2-8-0 locomotives they were built from in every regard.

Engineer Steve Wickersham, who operated the Reading T1’s, stated “On one trip there was a couple of rolling hills. It was fun because we could make the T1 work without having her down on her knees. We took off and all at once and we were doing the maximum they allowed, which was 50 mph, in no time. It was very much a Woah Seabiscuit operation.

“She just took off like a dragster. It was fun, and it would even throw the fireman off a little bit because he is expecting to have 10 or 15 minutes to get up to speed, and it only took 5. The next thing you know the engineer, me in this case, is easing way off the throttle and he’s losing his draft in the firebox which keeps the fire burning hot, and saying, ‘well now what do I do?’”

Steve goes on to say, “The synchronization between the engineer and the fireman is critical, each to the other. A good engineer is firing the engine in his mind when he runs it. A good fireman learns about running the engine by experiencing the cause and effect of things like the engineer making throttle adjustments, steam volume adjustments to the cylinders, and braking, because you are integrally involved with the behavior of the engine while each of you are hanging on for dear life on your side of the cab doing what you do. Blowing the whistle is the gravy!”

With the large investment railroads had to make in purchasing new, or rebuilding existing, steam locomotives for the war effort, it is understandable why railroads continued to heavily use them after the war. Additionally, some railroads such as the Norfolk & Western still believed in coal-powered steam locomotives, and continued to buy or build them up through 1953.

However with the creation of EMD’s FT diesel-electric locomotive, and the subsequent F3 and F7 models that followed throughout the 1940s, by the early 1950s most railroads knew that the savings of this new source of motive power in fuel costs, maintenance costs and crew costs could not be ignored.

Coal was more expensive to purchase versus diesel fuel. A steam locomotive’s time and costs of being serviced, repaired, and inspected far exceeded that of a diesel. Additionally, every steam locomotive used to pull a multi-locomotive powered train required a crew of two, compared to the diesels which could have multiple units connected with one crew of two controlling all of them.

It can be argued that if it were not for World War II, the dieselization of America’s railroads would have happened 10 years earlier. Immediately after the war, two of the three large steam locomotive builders, Alco and Baldwin, began mass production of diesel locomotives and orders for new steam power dropped sharply.

Thankfully, several railroads, communities, and museums saw the historical significance that the steam locomotive contributed to in the building of America, as well as in creating the modern way we now live.

There are approximately 1,200 steam locomotives left in existence in North America today of all different sizes. About 100 or so are operational at any given time on tourist railroads, at museum sites, or for special occasions running at hosting railroads, for us to still enjoy the sights, sounds, and smells that can only be provided by being in the presence of one as it chugs down the rails.

Forrest Nace is a steam locomotive historian and preservationist.