How Efficient are Steam Locomotives?

Steam locomotives were the world’s first true form of mass transportation, and while they have been replaced by newer technologies in most parts of the world, they still captivate the hearts of adults and children everywhere. How efficient are steam locomotives when compared to their diesel and electric counterparts? Are they still in use today? 

The Different Types of Locomotives

There are several types of locomotive engines in use around the world today, and they are powered in a variety of ways. Each of these engines has its own inherent set of pros and cons, as well. 

  • Steam locomotives get their pulling power from steam engines. These engines start with boiler systems, which utilize burning coal, wood, or oil to heat water until it steams. Then, the steam pushes on pistons in the engine, and the movement of the pistons causes the wheels to turn. 
  • Electric locomotives are those that take their power from electricity, and there are two different types. Some electric trains rely on an overhead pickup; contact is made with an overhead electrical wire, which transmits power to the engine. Others utilize a third rail, which conducts power in much the same way as the overhead pickup, but it is located on the underside of the locomotive, instead. 
  • Diesel locomotives utilize a diesel combustion engine – much like you might find in a semi truck or a school bus – for power. These engines are still in use around the world today because they are practical, they produce less pollution, and they’re easier to maintain. 
  • Slug locomotives are sometimes called drones, and while they don’t provide power themselves, they are connected to diesel-electric locomotives to provide better braking and more traction for a safer ride. The slug has motors, but they are powered by the “mother,” or the main locomotive. 
    • Gas-electric locomotives are quite rare in the world today, but they do still exist. The electric generators or alternators that drive the motors are powered by gas turbines. When the oil crisis hit in the 1970s, these trains were put on the back burner due to the sheer volume of gas needed to power them. 
  • Hybrid locomotives are one of the more common types of locomotives today. They utilize a fueled power source and electric engine, but they also have a rechargeable “battery” on board, much like today’s hybrid cars and trucks. The battery power is uniquely utilized; it captures the kinetic energy of the train and converts it into braking power. 
  • Fuel cell-electric locomotives are the newest of these technologies, and they convert hydrogen to energy via fuel cells. They were introduced in Canada in 2002, and only a few places utilize them to this day. 
  • Steam-diesel hybrid locomotives still exist in places like Russia and the UK, but they are no longer on the tracks. They were originally designed so that they could use either diesel or a boiler to move their pistons, but the cost of fuel oil was so high that the idea was scrapped. 

Back in the 1950s when the world was only just discovering the true potential of nuclear power, an atomic-electric locomotive was proposed. Due to its potential danger and cost (it would have required a 200-meter reactor and a 1.5-meter thick lead coating), the idea was scrapped. 

The History of the Steam Locomotive

The invention of the steam locomotive was a turning point in human history. For the first time, it was possible to transport large quantities of goods, animals, and even people in a way that was fast, cheap, and reliable for its time. In fact, the steam locomotive paved the way for the rail system that ultimately led to the Industrial Revolution and the technology that we all use today. 

rio grande
Bill Hooper

The first steam engine was introduced to the world back in the 1770s by a Scottish inventor named James Watt. He patented his invention so that no one else could benefit from his idea, but Watt never saw his invention come to fruition. It wasn’t until 30 years later when the patent expired that inventors really got the opportunity to bring steam locomotion to life. The first fully-functional steam engine was introduced by Richard Trevithick, and it was by far the most efficient prototype in existence at the time. 

It’s important to note that prior to this, no one believed it was possible to use a steam-powered engine for any sort of real industrial use; it simply wouldn’t be powerful enough. However, Trevithick proved them all wrong and pulled a 10-ton load over a 10-mile journey just to show a mine owner that it could be done. Although Trevithick’s steam engine wasn’t successful in the end, his ideas and determination fueled innovation from all around the world. 

The first successful steam locomotive is attributed to Matthew Murray. In 1804, he built the world’s first fully-functional steam locomotive. In 1812, Murray’s Salamanca locomotive with its twin cylinders went public. The inventor of the first steam locomotive for public transport was George Stephenson, who is best known for creating “Locomotion” in 1825. It ran the Stockton and Darlington railway in England for many years. A little while later, Stephenson designed and successfully manufactured “The Rocket”, which had a revolutionary pressurized boiler that allowed it to reach a top speed of 45 miles per hour while carrying 30 people. Locomotives like “The Rocket” were the first to spread, and by the mid-1800s, they were all over England. 

Steam engines are no longer used for mass transportation, but many have been preserved and/or restored to serve as tourist attractions. In the US alone, there are dozens of locations where individuals can board a steam-powered train for that sense of nostalgia. As of the time of writing, two steam locomotives still operate today – the Union Pacific Nos. 844 and 4014.

steam engine
Jeff Hampton

Steam Locomotive Efficiency

Believe it or not, steam locomotives weren’t phased out entirely in the United States until the 1960s, and they were replaced with diesel or electric engines. Both of these options were more efficient (and thereby cost-effective) than their steam counterparts. 

How efficient are steam locomotives? They aren’t efficient at all. Only about 5% of the potential energy produced by a steam locomotive’s boiler is translated to the wheels in the form of actual driving power. That means that 95% of the energy produced by burning the coal, wood, or oil was lost. Conversely, a diesel engine is 45% efficient – significantly more than its steam counterparts – and today’s modern electric engines are a whopping 95% efficient, making them the most efficient locomotives in existence. 

In the early days of steam locomotion, there was plenty of fuel to go around. Coal, wood, and oil were everywhere. By the 1960s, it was a different story. Growing populations demanded more housing – and more electricity and heating for that housing- which came with higher costs. Costs were already on the rise by the time the first diesel engine was introduced to the railroad in 1934; that year, the “Zephyr” had its maiden journey from Denver, Colorado to Chicago, Illinois. The technology was still experimental, and because the economy was only beginning to recover from the Depression Era, there simply wasn’t enough money to put into it. The success of that single journey set the stage for the new rail era to come, though. 

up fef northern
Roger Puta

Eventually, the demand to reduce transportation costs eclipsed the reluctance to invest in new technologies. Diesel engine designers promised that their new technology would be more affordable to utilize, that it would be faster, and that it would be able to travel further without having to stop to refill the oil and water for the boiler.  

It’s also helpful to note that maintaining a steam engine was also a difficult and expensive endeavor. Federal law at the time required monthly maintenance, which included cleaning the cisterns – a massive undertaking. Aside from that, the engines required major renovations almost constantly to keep working. Steam engines were only available about 35% of the time because of the need for constant maintenance, but diesel engines were available 95% of the time because their maintenance needs were very low. 

Horsepower Comparisons 

Like cars and trucks, the pulling power of a locomotive can be measured in horsepower. Steam locomotives are long gone, and most of today’s powerful freight trains are diesel-powered. They are fast, efficient, and relatively easy to maintain, which makes them the best option available for hauling large amounts of freight over long distances. Modern locomotives have a wide range of horsepower capabilities; some boast about 1000, but others can have as much as 18,000. Modern locomotives tend to have a horsepower rating at or above 10,000, and this is even true for today’s newer electric locomotives.

locomotive driver
Jonathan Lee

Steam locomotives, on the other hand, are a different story. The largest steam engine ever built is the Union Pacific No. 4014, which is still operational today in Wyoming. It was created solely for the purpose of hauling large objects without the need for additional locomotives to help it. This massive locomotive weighs 600 tons (just the locomotive!) and is 132 feet long. It boasts 6290 horsepower, can hit a top speed of 70 miles per hour, and can run for about 100 miles before it needs to be serviced. 

When it comes to sheer power and horsepower, a diesel engine is still a better choice than a steam engine. First and foremost, starting power is a major consideration. A diesel combustion engine can provide full driving power right away, whereas a steam engine has to work its way up to full power and takes a very long time to accelerate. Perhaps the biggest difference between the two in terms of power is the fact that diesel locomotives can be combined to carry especially heavy loads. This simply isn’t true of steam engines; only one can be attached to a load at a time, and the size of that load will ultimately determine the locomotive’s acceleration rate, too. 

The Most Powerful Steam Locomotive Ever Built

The world’s most powerful steam locomotive is a hotly contested topic, but most would agree that the winner is the C&O “Allegheny”. This locomotive was built for the Lima Locomotive Works and ran almost exclusively on the Chesapeake & Ohio railway. It boasted an articulated design with a 2-6-6-6 wheel arrangement, and in terms of raw horsepower and tractive power, it’s quite possible that it was the most powerful steam locomotive ever built. It was also one of the heaviest; when loaded with its tender of 25 tons of coal and 25,000 gallons of water, it weighed in at nearly two million pounds – and that’s without its freight. 

locomotive 4014
Jonathan Lee

It was created for the purpose of pulling many tons of West Virginian coal between West Virginia and Virginia, and while it was designed to achieve high top speeds for its time, it was never actually intended to be used at such speeds. The “Allegheny” was as much about bragging rights as it was functionality in that regard. Amazingly, when Lima’s new design was tested, it produced almost 7500 horsepower and more than 110,000 pounds of tractive effort – much more than even the Union Pacific No. 4014! It could pull 5000 tons of coal at an absolutely astonishing 45 miles per hour, and it was rated to carry twice that amount – up to 10,000 tons! 

Despite its impressive power, the locomotive was just as inefficient as the others. C&O originally purchased 60 of these massive machines, but they were only in service for 15 years before the last one was removed from the tracks. 58 of the engines were scrapped, leaving only two behind. One of these – No. 1601 and the second “Allegheny” manufactured by the hands of the workers at Lima – is located at the Henry Ford Museum in Dearborn, Michigan. 

Steam locomotives were introduced nearly 500 years ago, and since then, they have captured the hearts of people around the world. Though only one continues to operate on a freight line, there are dozens out there that can be seen in museums or even ridden along historic railways. Though they were the most inefficient locomotives, they forever changed the United States for the better. 




Lifelong Rail Enthusiast and Owner of Worldwide Rails

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