An iconic image of a train is a large engine with a huge column of smoke blowing out its top.
This train was a steam engine, and steam was the first fuel source that trains used to power themselves.
Trains and their fuel sources have evolved since then.
Since we no longer see large columns of smoke rising from trains, you may wonder what fuels them.
Here’s what you need to know about trains and their fuel sources.
What Do Trains Use For Fuel?
Trains use three primary sources of fuel.
Those sources include:
Although all trains started with the steam engine, most steam engines used today are primarily for tourism or historic purposes.
That said, there was a time when steam engines ruled the world.
Most modern trains run either on electricity or use a diesel-electric combination.
Here are each fuel sources in detail.
Steam engines got their start in the early 1800s.
They were the go-to choice of powered engines for their power and reliability.
Most of the engines in the Industrial Revolution used steam as a fuel source, and trains were no different.
Steam trains were among the first motor-powered locomotives.
Since they had so many moving parts, they required many workers to operate those moving parts and keep the engine running.
In the beginning, there were two main ways to fuel a steam engine.
They were coal and wood.
Steam engines had a furnace inside of them.
Workers would keep the furnace full of either coal or wood.
They’d shovel the coal into the furnace or throw the blocks of wood into it.
As a result, the furnace would burn and produce the steam which powered the engine and kept it running.
Coal and wood eventually fell by the wayside when oil became prominent.
Manufacturers found a way to start and fuel steam engines by lighting oil instead.
Train companies preferred using oil because it was cheaper and easier to store than either coal or wood.
Since it was a liquid, they could store more of it on the train without having to worry about running out of fuel.
It was also easier since coal had to frequently be re-lit to keep producing heat and steam.
Oil simply needed lighting once, and then it was off as long as there was enough oil in the engine.
Oil engines became more popular in the 1920s.
This was because there was a higher production of cars.
With more cars on the road, the demand for oil increased.
That meant it was easier and cheaper to get their hands on oil.
How A Steam Engine Works
Steam engines are complex machines that require several hands to operate.
It all starts with heating the steam engine’s boiler.
The boiler then heats the pipes that sit beside it.
The heated pipes then raise the temperature of the water.
As the water becomes hot and boils, it produces steam.
The steam then transfers down to the wheels which turn it.
There’s a pair of cylinders at the front of the train to turn side-rods.
When the steam interacts with the side-rods, that actually turns the wheels.
Back before oil, trains had to carry their tinder in a different car.
It wasn’t uncommon to see a train carrying a bunch of wood or coal at the back of it.
This ensured that it was far enough away to be safe and not accidentally catch fire.
However, it also meant that the workers had to walk back and forth to get more fuel when the engine was running low.
When trains switched to oil, they were able to store it a bit closer, which meant getting more fuel was easier.
2. Diesel-Electric Power
A new type of engine emerged in the 1930s.
The first major one used for passengers came from Electro-Motive Division.
They made a new line of locomotives that they called the E-Series.
They used a diesel engine that used diesel fuel for power.
At first, diesel engines were primarily used to move passengers along the track.
However, they started using it for freight, too, and it’s still common to see diesel-electric engines in use today for both passengers and freight.
It didn’t take long for diesel engines to replace steam engines either.
It made financial sense.
For one, diesel was cheaper than coal, wood, or oil.
They were also able to store a lot more of it with ease.
Since it had great fuel efficiency, trains also had to use far less of it to get along the tracks.
That meant it had fewer costs associated with fuel.
Since the operation of the engine was easier, the train also needed fewer crew members to operate it.
They were able to tighten up their crews and spend a little less money on labor costs.
Finally, diesel engines are lighter than steam engines.
They put less strain on track infrastructure and the train itself.
This meant that the railroad company had to spend less money on repair and replacements of the tracks each year.
It also means that they were able to get more use out of the diesel engine before shutting it down for repairs.
Steam engines, due to all their moving parts and weight, spent at least half of their operating time under maintenance.
Switching to diesel engines just made financial sense.
How Does A Diesel-Electric Engine Work?
The diesel generates a current that powers the electric traction motors.
These motors then power the axles.
In today’s railroads, some tracks are already electrified.
This helps reduce the amount of diesel that a train needs to use since it can use the tracks to power the axles instead.
Also, thanks to electrical connections, the crew can all operate their various positions in the lead unit.
They’re no longer spread throughout the train and unable to communicate with one another effectively.
That means that if the conductor notices something on the tracks, they can immediately warn the crew, who can then immediately take the appropriate action.
This helps reduce the chances of a train collision.
Diesel engines are a lot more efficient than steam engines.
According to CSX, which is one of the major railroad companies of today, their trains can cross 492 miles on a single gallon of diesel fuel.
3. Gas-Turbine Power
There’s another type of fuel that some trains use.
Around the same time that diesel engines started to gain prominence, gas-turbine power was another type of fuel source for trains.
It was in France that they discovered this type of fuel source.
They created an engine that worked similarly to diesel but used gas instead.
The French put it to work, and the engine eventually came to the United States.
It got on the tracks in the 1940s, but it stopped its use in the 1960s.
The primary reason that they decided to retire these types of locomotives in the United States was that they weren’t as efficient as diesel engines.
With the price of oil and gas increasing, railroad companies had an interest in keeping costs low by using fuel-efficient locomotives.
That said, the gas-turbine engine saw a new kind of popularity in the passenger revenue stream.
While it didn’t do well in the freight industry, the French released their TGV 001 locomotive in the 1970s.
It became quite popular among passengers, and so the United States used the engine again.
In particular, they made the UAC Turbotrain and Amtrak made the RTG and RTL Turboliners.
They primarily used these types of locomotives in the Midwest and Eastern parts of the United States.
Eastern Canada also used these locomotives.
While they’re not as common as many other types of locomotives, it is possible to see a few gas-turbine engines today.
How Do Gas-Turbine Engines Work?
Gas-turbine engines work very similarly to diesel-electric engines.
The main difference is the gas which turns the traction motors instead of diesel.
Everything else, on the other hand, works more or less the same.
The axles turn and the engine moves.
The primary problem with gas-turbine engines is that they can’t use the existing electricity along the tracks like diesel-electric engines.
Because of this, the gas is in continuous use to power the engine.
That makes it less fuel-efficient than diesel engines.
4. Electric Power
Electric trains have been around longer than most people realize.
They got their start as early as 1910.
The Hudson River Tunnels faced a unique challenge.
They wanted to extend the Philadelphia–New York mainline through the tunnel, but the steam engine wasn’t allowed in the tunnel.
That’s because the tunnel was so extensive that the fumes from the engine became a danger to everyone in the tunnel.
They needed a new type of engine.
The PRR began work on the DD-1 electric locomotive to overcome this problem.
They were successful, and electric trains became more and more popular as the years went on.
In particular, they became popular for their use in high-speed rails.
One of the most notable high-speed projects was in Japan.
In 1964, Japan opened its Shinkansen service.
It became part of the Tokaido line.
The train was able to travel at speeds faster than most others could reach at that time.
It saw great success and prompted other countries to experiment with high-speed rails.
Another notable country was France.
They created the TGV line which got its start in 1981.
Their first line with their new electric train was the Sud-Est line, which ran between Lyon and Paris.
It was another success, and there have been many high-speed rail projects since.
Most lines in Europe and Japan tend to invest in high-speed rails over other types of rails since it increases the use of the trains.
Passengers are more likely to use a high-speed train because it saves them time traveling.
They’re more likely to use a high-speed train to travel if it gets them to their destination faster.
As trains become more advanced and faster, some might start to choose a train over a plane for long-distance travel since it’s usually cheaper.
Those who are afraid to fly will also see the appeal.
Electric-powered trains are, for the time being, the future of railroads.
How Does An Electric Engine Work?
If you step onto a railroad track, then you may wonder if the tracks have electricity running through them.
They most certainly don’t as this would cause several lethal problems.
Instead, electric trains get their electricity from overhead power lines.
Some trains also use a DC third rail to power the engine.
The actual process of powering an electric train is lengthy.
It begins by collecting an electric current from the overhead power lines or the DC third rail.
This current then goes to a transformer.
The transformer sends the current to a rectifier.
The rectifier changes the current from AC to DC.
It then passes the direct current to the inverters.
The inverters transform it from DC back to AC.
At this point, the phase three current goes to the traction motors.
These motors power the wheels and get them moving.
If the train has any spare current from the process, then it safely delivers it back to the power line.
This also promotes efficiency and cuts down on electricity waste.
Electric power is the most fuel-efficient option.
It’s also the least costly since electricity is relatively cheap.
The engines are also lighter, which makes them cheaper to make and run.
They need less maintenance than the rest of the engines.
Since it’s cheaper to run and operate, it helps railroads save a good amount of money.
It also helps cut down on the amount of waste that trains produce, which pleases passengers and the general public concerning the environment.
What Kind Of Diesel Do Trains Use?
Diesel-electric trains use ultra-low sulfur diesel.
This has a sulfur content of up to 15 parts per million.
After 2014, all diesel trains had to switch to this type of gas.
It was an effort to make them more environmentally friendly.
Do Trains Still Run On Coal?
It’s rare to see steam engines in use today, but there are still a few of them out there.
Some coal-powered trains primarily move coal across the United States.
Others are for show or act as a tourist attraction.
For example, people can buy tickets to ride on a steam engine and take part in the old 1800s or 1900s lifestyle.
Steam engines are a classic part of Americana culture.
As such, there are quite a few lines that pass through scenic countryside which use steam engines.
The idea is to make a tour that capitalizes on the romance of the past.
That said, most trains in use today are either diesel-powered or electric-powered.
Steam engines are primarily tourist attractions.
How Much Fuel Does A Train Use?
The amount of gas that a train uses largely depends on a few things.
In particular, it depends on the number of carriages that it’s carrying and its cargo.
For example, if a train has a high number of carriages, then they’re pulling more weight, which means there’s more friction for the train to overcome.
As a result, it will require more fuel to overcome that friction and move.
That also goes for trains that are carrying heavy cargo.
No matter if they have a lot or a little heavy cargo, the weight makes it difficult for the train to move.
CSX stated that a typical route for them requires 423,998,863 gallons of fuel.
The length of the journey clearly impacts how much fuel the train is going to need and use.
Although trains started with steam engines, they have since evolved into efficient engines that run on diesel, gas, or electricity.
In particular, electric trains have been the most popular as electricity has unlocked the ability to travel at high speeds.
Considering the focus on climate protection, it’s likely that electric trains are going to become the new norm.