You may have wondered why some trains have multiple engines… and especially why some trains have an engine in the middle! I will do my best to answer these questions below.
Please note that I use “engine” as a synonym for “locomotive”, which is the technical term.
The Short Answer
Trains have multiple engines to provide more power to pull the train. Each locomotive has a certain amount of pulling power (called “tractive effort”), which is related to how many horsepower the diesel engine in the locomotive has. There’s a limit to how much tractive effort one locomotive can deliver, so railways connect multiple locomotives together to be able to pull more cars.
Multiple Steam Engines
In the days of steam engines, every locomotive had its own crew – an engineer to drive it, and a fireman to shovel the coal into the firebox to power the locomotive. (There was also a conductor and head end brakeman but they weren’t there to operate the locomotive itself, just the train)
As trains grew in length, railways built larger and larger locomotives. The famous Union Pacific “Big Boy” locomotives were one of the largest types, able to haul 3,600 tons of train up some serious hills. However, if you wanted to put more cars in a train than a Big Boy could haul, the only solution was to add more locomotives.
In steam days, this was called “double heading” (for 2) or “triple heading” (for 3).
Double heading was done, but it was awkward and expensive. It required a separate crew for each locomotive, costing the railways a lot of money to pay them. Also, this was before radios were used for train control, so crews had to communicate using the steam whistle to tell each other to speed up, slow down, or apply brakes.
Multiple Diesel Locomotives
When diesel locomotives started to be used, it wasn’t long before the railways wanted to connect them together to operate several locomotives as if it was one. This is called “MU” for “Multiple Unit”, and over time a standard evolved so most locomotive types can be mixed and matched together today. They don’t even have to have the same horsepower rating.
The engineer and conductor sit in the lead locomotive and control all locomotives from there. All locomotives in the train get the same throttle setting or brake applications.
This made it simple for railways. They could look at how many tons needed to be hauled, how steep the hills were on the route to be taken, then figure out how many locomotives were required to pull the train over the route.
There is a limit to how many locomotives can be added to the front of a train, but in general there can be up to six or seven without a problem. Most trains in North America will have at least two locomotives.
Some of the limits have to do with train handling, which leads to…
Why Do Some Trains Have An Engine In The Middle?
Some trains will have locomotives in the middle of a train, or even on the tail end. This is called “distributed power” and the locomotives are usually referred to as “DPU” (Distributed Power Units). The DPU locomotives have radio equipment in them so they can be remotely controlled, but otherwise they are usually normal locomotives that could have crew in them and could lead trains. There are some locomotives that have no crew cabs but they are rare.
Control equipment in the locomotive leading the train send commands to the DPUs via radio to increase or decrease the throttle, or to apply or release the air brakes. Most software used to control these remote locomotives can handle several DPUs at once at different parts of the train.
Why Use Remote Locomotives?
There are a couple of reasons to use remote locomotives instead of having all of them at the front of the train.
Train Handling
Trains often go around long curves, often at higher speeds like 40, 50 or 60 miles per hour. With all of the locomotives pulling on the front of the train, this leads to a tendency to pull the train straight through the curve (called “string lining“).
You can see this if you take a string, lay it on the floor in a curve, then pull on one end. The string tends to straighten out, and that’s what the train “wants” to do when all of the pulling is done from the front.
This can happen especially if there are a lot of empty, light cars with heavy, loaded cars behind them. Railways try to arrange cars in the train to avoid this.
One way to reduce the risk of string lining is to put some of the locomotives in the middle or end of the train, so that not all pulling is done from the front.
Air Brakes
Trains use air brakes to slow or stop the train. Each car has air hoses on each end that connect together to make a continuous air line from the front of the train to the end. Air compressors in each locomotive add air to this air line. During cold weather, the connections between cars can leak and it’s hard to keep air pressure up on a long train. Having locomotives distributed through the train can help add air throughout the train to keep air pressure up.
Train brakes are applied by reducing the air pressure in the brake line. Each car’s brake equipment “notices” this reduction in pressure and applies the brakes in the car.
It takes time for the reduction in air pressure to travel through the brake line, especially for a train that could be two miles long. Brakes in the rear of the train could still be coming on while the locomotive has released the brakes and is accelerating.
Having radio-controlled locomotives throughout the train means that the reduction in air pressure can be done at different points in the train at the same time, so more brakes come on quicker.
This one is simple – locomotives can run forward or backward at equal speeds. The direction doesn’t matter, especially for diesel-electric locomotives.
It can be uncomfortable for the crew if the lead locomotive runs backwards, because the controls are set up in the cab to operate “forward”. The engineer basically has to look backward all the time while running the train. Imagine driving your car in reverse for several hours!
This is why you often see two locomotives “back to back”, so that if the engines have to be disconnected from the train, the crew can swap locomotive cabs and run the engines “forward” no matter which direction the engines are going.
Anyway, the reason for using two locomotives is pretty simple. Twice the number of locomotives means twice the power. This extra power boost is used for especially heavy loads or for trains going up steep grades. A really steep grade could require as many as eight locomotives.
Each car of the train has its own traction motors: by means of motor control relays in each car energized by train-line wires from the front car all of the traction motors in the train are controlled in unison.
As wireless technologies advanced in the 1960s, freight railroads began adding extra locomotives to the rear of trains to give them enough power to climb steep hills. This is how distributed power was born.
Trains operated under the Chessie name from 1973 to 1987. Washington, D. C. Headquartered in Cleveland, Ohio, the Chessie System was the creation of Cyrus S. Eaton and his protégé Hays T.
For the most part, it doesn't matter which way a modern locomotive faces, it works just fine either way. Typically though, the main reason some locomotives will be facing backwards is because turning trains is not always easy. In the past, you would need a wye, loop, or turntable to turn a train/locomotive around.
DPU – Stands for Distributed Power Unit, a locomotive set capable of remote-control operation in conjunction with locomotive units at the train's head end. DPUs are placed in the middle or at the rear of heavy trains (such as coal, grain, soda ash and even manifest) to help climb steep grades, particularly in the West.
If you own two, you get $50 rent from anyone landing on either, if you own three then you get $100, and if you own all four railroads then the rent is $200. However, the owner must ask the player for the rent before the next player rolls the dice.
Today's train locomotives are already quite fuel efficient, especially compared to trucks. In fact, trains can haul one ton of goods an average of more than 480 miles on just a single gallon of fuel, making them 3-4 times more fuel efficient than trucks.
Until the 1980s, laws in the United States and Canada required all freight trains to have a caboose and a full crew, for safety. Technology eventually advanced to a point where the railroads, in an effort to save money by reducing crew members, stated that cabooses were unnecessary.
They were initally nicknamed "Black Staniers" by contrast with the "Red Staniers" - the Jubilee class of express passenger locomotive. Soon, however, the name had become "Black Fives" and the moniker stuck. So useful did the locomotives prove that 842 examples were built over a 17-year period until 1951.
The engine, or locomotive, powers the train by pulling the cars from the front. Generally, engines are powered either by some sort of fuel carried on the train.
A train can consist of a combination of one or more locomotives and attached railroad cars, or a self-propelled multiple unit (or occasionally a single powered coach, called a railcar). Trains can also be hauled by horses, pulled by a cable, or run downhill by gravity.
After the war, much of the line was repaired and to this day is still used for local passenger services between Bangkok and the end of the line at Nam Tok.
In the public announcement, it was said that 'CSX is singularly appropriate. C can stand for Chessie, S for Seaboard, and X actually has no meaning. But X could be used as a short term for the word Express, taking off the E, giving out Xpress, putting the X in use.
BNSF Locomotives. We have one of the newest locomotive fleets in the industry. A typical BNSF locomotive will travel up to 4.8 million miles in its lifetime - equal to about 20 trips from the earth to the moon.
Cars in the front of the train are usually more steady feeling than the cars near the end. The optimal seat to prevent motion sickness is a seat in the middle of one of the first train cars. Be sure to choose a forward-facing seat, and if you're riding a double-decker train, stay on the bottom level.
Safety experts also recommend choosing a rear-facing seat, because a person sitting there is less likely to be thrown forward during a collision. Trains are more likely to hit something side-on than head-on or from behind, according to the FRA.
Cabooses were often painted red for safety reasons. Although red became the traditional color, some railroads painted their cabooses to match their locomotives or freight cars. Cabooses disappeared for several reasons. Railroads installed track-side equipment to detect freight car wheel defects and dragging equipment.
There are three types of railway engine: mechanical, hydraulic or electric. Most diesel locomotives use electric transmission and are called "diesel-electric" locomotives. Mechanical and hydraulic transmissions are still used but are more common on multiple unit trains or lighter locomotives.
national railways, rail transportation services owned and operated by national governments. U.S. railways are privately owned and operated, though the Consolidated Rail Corporation was established by the federal government and Amtrak uses public funds to subsidize privately owned intercity passenger trains.
The US economy is colossal. In fact, it represents more than 20% (1/5th) of the entire global economy. So, with corporate profits generally on the up, what industries are the biggest profit-makers?
The Great Depression of the 1930s forced some railroad companies into bankruptcy, creating hundreds of miles of disowned and subsequently abandoned railway properties; other railroad companies found incentive to merge or reorganize, during which excess or redundant rights-of-way were abandoned.
The life expectancy of diesel-electric and electric locomotives is expected to be similar—about 25 years. Both types of motive power are subject to technological obsolescence.
Brakemen, switchmen and flagmen would often ride in the caboose, which also served as bunkhouse and cook shack for the crews, as well as a rolling infirmary if first aid was needed. It was also the crew's restroom -- the toilet is behind a door at the front end.
Most will be scrapped, but some will be purchased privately. Typical prices for steel-bodied boxcars and cabooses run between $2,000 and $4,000. Wooden cars, when they can be found, are generally cheaper.
Once the train was stopped, the flagman would descend from the caboose and walk back to a safe distance with lanterns, flags and other warning devices to stop any approaching trains.
Puffing Billy is the world's oldest surviving steam locomotive, constructed in 1813–1814 by colliery viewer William Hedley, enginewright Jonathan Forster and blacksmith Timothy Hackworth for Christopher Blackett, the owner of Wylam Colliery near Newcastle upon Tyne, in the United Kingdom.
He was named after James Furze, a friend of the publisher's son. He was originally painted black. At the request of the publishers, Awdry dedicated James the Red Engine to the character. James was painted red in this and subsequent books.
The white flag indicates that an extra train, one not on the schedule has been temporarily added. The yellow flag indicates that a train should approach, but proceed with caution and be prepared to stop if necessary. The red flag indicates that the train should stop immediately.
A caboose is a train car that is usually at the end. If you are pulling up the rear, you could call yourself the caboose. The engine is the first car on a freight train, and the last car is usually the caboose. Besides being last, the other feature of a caboose is its use by the crew.
A cowcatcher, also known as a pilot, is the device mounted at the front of a locomotive to deflect obstacles on the track that might otherwise damage or derail it or the train.
Normally, the short hood is the front of the locomotive, and may be referred to as the locomotive's "nose". Originally, this was not the case; railroads preferred to have the long hood leading, for additional crew protection in a collision, and because it was the familiar mode of operating steam locomotives.
The conductor title is most common in North American railway operations, but the role is common worldwide under various job titles. In Commonwealth English, a conductor is also known as guard or train manager.
A combine car in North American parlance, most often referred to simply as a combine, is a type of railroad car which combines sections for both passengers and freight.
Population Density. The US simply does not have the density to have the need for high speed rail. There are a few regions where this is actually a viable thing, and one region in the US already has a high speed rail line, called the Acela Express. It runs from Boston, Massachusetts to Washington, DC.
In the United States, just outside Watervliet, New York, there is the main line for the Delaware and Hudson Railway. Alongside this railway line is a disused stretch of track which is home to rusted locomotives, passenger cars, and freight cars.
Fourteen years later, construction is now underway on part of a 171-mile “starter” line connecting a few cities in the middle of California, which has been promised for 2030.
The era of the freight train-hopping, job-seeking hobo faded into obscurity in the years following the Second World War. Many hobos from this era have since “caught the westbound,” or died. A small number of so-called hobos still hop freight trains today.
The Middleton Railway in Leeds, which was built in 1758, later became the world's oldest operational railway (other than funiculars), albeit now in an upgraded form.
Beginning with the 4449 in 1974, each locomotive was eventually moved to the Brooklyn Roundouse in SE Portland. Since moving from Oaks Park, volunteers have spent thousands of hours restoring and caring for these beautiful locomotives. Two are now operational and one is continuing to be restored.
The traditional location for engines is under the floor, which would require raising the floor which would reduce accessibility, and make the train noisier for passengers. Engines in the middle keeps the train rotationally symetric.
' Long-haul trailers loaded with products are generally referred to as freight trucks. So, traditionally speaking, 'freight' is products or goods moved overland via truck or train, whereas 'cargo' refers to goods moved overseas via ocean carriers or through air providers.
A caboose is a train car that is usually at the end. If you are pulling up the rear, you could call yourself the caboose. The engine is the first car on a freight train, and the last car is usually the caboose. Besides being last, the other feature of a caboose is its use by the crew.
CSX does not own or provide tank cars. Bi-level and tri-level rail cars are designed to transport pick-up trucks, minivans and sports utility vehicles. Each rail car has a maximum load capacity of 10 to 15 vehicles.
Until the 1980s, laws in the United States and Canada required all freight trains to have a caboose and a full crew, for safety. Technology eventually advanced to a point where the railroads, in an effort to save money by reducing crew members, stated that cabooses were unnecessary.
Black locomotives became common beginning in 1880, after coal burning engines made grime commonplace. Black was chosen because black locomotives didn't show all the dirt and grime that covered the locomotive during normal use.
Introduction: My name is Dr. Pierre Goyette, I am a enchanting, powerful, jolly, rich, graceful, colorful, zany person who loves writing and wants to share my knowledge and understanding with you.
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