Steam Locomotive Wheel Arrangements: Train Talk Ep. 10

Steam Locomotive Wheel Arrangements: Train Talk Ep. 10

Hello everyone and welcome to Train Talk! Today, we are going to talk about classifying
steam locomotives into various groups, based on the number and types of wheels they have,
also called a wheel arrangement. During the steam era, many manufacturers produced
a wide variety of steam locomotives, most of which were built specifically for a particular
railroad. To make things even more complicated, many
railroads had their own systems of classifying steam locomotives for purposes of keeping
track of them. So, one of the best ways to organize steam
locomotives was based on their wheel arrangement. Wheels are grouped into three types: pilot
wheels, driving wheels, and trailing wheels. The pilot wheels help guide the heavy locomotive
around curves. Driving wheels are the wheels that actually
move the locomotive and train down the track. These wheels are powered by taking the pressure
of expanding steam and using it to move the large connecting rods that are attached to
the drive wheels. The trailing wheels help support the weight
of the fire box. Keep in mind, not all steam locomotives have
pilot wheels or trailing wheels, and some locomotives don’t have either. Additionally, there are some locomotives that
have two different sets of driving wheels, but we will get to that in a minute. Ok, so we’ve grouped our basic types of
wheels, now what do we do? The most used system of designating wheel
arrangements is known as the Whyte classification system, named for its creator Frederick Whyte,
a mechanical engineer employed by the New York Central railroad. The Whyte system denotes wheel arrangements
by counting the number of a certain type of wheel on both sides of the locomotive, starting
at the front and working back with different sets of wheels separated by a hyphen. For instance, a locomotive with two pilot
wheels, eight driving wheels, and two trailing wheels would be called a 2-8-2. It is important to note that when we are counting
the wheels, we are counting what is on both sids of the engine. So, while you can only see half the wheels
when looking at one side of the engine or the other, we are counting wheels on both
sides, which is why this locomotive is called a 2-8-2 and not a 1-4-1. This locomotive, which has 2 pilot wheels,
8 driving wheels, and no trailing wheels is designated as a 2-8-0, the 0 indicating the
lack of trailing wheels. Well, that’s pretty much the basics of it. In addition to these number and hyphen designations,
many wheel arrangements were given names. Let’s go through some of the most common
wheel arrangements now. The 4-4-0 was one of the most widely and longest
used wheel arrangements of steam locomotives ever produced. It was given the name “American”, because
it was really the railroads of America that pioneered the use of this wheel arrangement. 4-4-0’s were used almost exclusively throughout
the mid 1800’s and they were still being produced as late as the 1940s. This is really the locomotive that most people
think of when they imagine the trains of the old west, often adorned in bright and colorful
paint schemes and plenty of brass. 4-4-0’s were so popular because they were
quite versatile. They could be used for either passenger or
freight service. The bigger the diameter of the driving wheels,
the faster they were designed to go. Today, there are a number of 4-4-0’s that
still run in tourist and museum service, the oldest of which was built in 1856. The 2-8-0 wheel arrangement, named the “consolidation”
was developed in the 1860s and was another of the more common wheel arrangements of steam
locomotives produced. According to, the name
“consolidation” actually comes from the consolidation of two different railroads into
the Lehigh Valley Railroad, which happened around the same time the wheel arrangement
was first produced. Due to their rather short drive wheels, consolidations
were limited in their top speed, so they were often used to pull heavy freight trains. Consolidations were produced well into the
first half of the 1900s and they were used right up to the end of the steam era in the
United States. Currently, consolidations are one of the best
preserved wheel arrangements of steam locomotives, and they are among the most common seen in
operation today. The 2-8-2 wheel arrangement was developed
in the late 1800’s and was named “Mikado”. This name comes from one of the first orders
of 2-8-2 locomotives being built for a railway in Japan. “Mikado” was the english word for the
Japanese Emperor at the time. Mikados were well balanced, multipurpose locomotives
used by many different railroads throughout the 1900’s. While they were primarily used for freight
service, they could be seen pulling passenger trains from time to time as well. Mikados, like consolidations, are a well preserved
type of locomotive and there are several examples that still operate today everywhere from tourist
railroads to mainline excursion trains. 4-6-2 locomotives, called the Pacific, were
primarily used for high speed passenger trains from the early 1900’s through the end of
steam in the mid to late 1950s. It is believed that the name “Pacific”
comes from the first operator of this type of locomotive, the Missouri Pacific, which
purchased its first Pacific locomotives in 1902. Today, a number of Pacifics remain in preservation,
but very few of them still operate. 4-8-4s were one of the most popular wheel
arrangement of big steam locomotives. They were named “Northern” because they
were first built for the Northern Pacific Railroad in 1927. These were powerful locomotives that were
built to reach speeds as high as 110 miles per hour. Northerns were often used as passenger locomotives,
but they also saw service on high priority fast freight trains. There are a number of preserved northern type
locomotives today, but very few of them still operate. Of the ones that do, they are primarily used
for excursion service out on the main line. Locomotives that did not have pilot wheels
or trailing wheels were called switchers and they were typically only used for moving cars
short distances. Switchers came with either 4, 6, or 8 driving
wheels and were designated as 0-4-0, 0-6-0, or 0-8-0. In addition to standard tender engines, tank
engines also use this same classification system. Tank engines are noted by putting a capital
letter “T” right next to the number of trailing wheels. For instance, this locomotive would be classified
as a 2-8-2T. There is one final addition to the wheel arrangement
naming system, and that is for locomotives that have multiple sets of driving wheels,
called “mallets” and “articulateds”. These types of locomotives are complicated
enough that I want to do an entire episode on them, so for this episode, we will just
focus on the wheel arrangements. Basically, they follow the same system of
designating wheel arrangements except the multiple sets of driving wheels are separated
with a hyphen. For example, the Union Pacific’s articulated
locomotive “Big Boy” has 4 pilot wheels, one set of 8 driving wheels, another set of
8 driving wheels, and then 4 trailing wheels, so it would be called a “4-8-8-4”. And this locomotive, a tank engine with 2
pilot wheels, 6 driving wheels, one more set of 6 driving wheels, and then 2 trailing wheels
would be called a “2-6-6-2T” Well, that covers pretty much everything. Now let’s try to figure out what these wheel
arrangements are, and learn a few new names too! 4-4-0 “American” 2-6-0 “Mogul” 2-6-2 “Prairie” 2-8-0 “Consolidation” 4-6-0 “Ten Wheeler” 2-8-2 “Mikado” 4-6-2 “Pacific” 4-6-4 “Hudson” 4-8-4 “Northern” 2-8-4 “Berkshire” 2-6-6-2T “Mallet” tank engine 4-6-6-4 “Challenger” Articulated Well, we’ve covered a lot in this episode. I hope you had fun! There are some other types of steam locomotives
that don’t follow the whyte classification system at all including “geared locomotives”
and cog locomotives, but we will cover those in future episodes. If you enjoyed the video, let me know by liking
it and leaving a comment below. And if you’re not already, be sure to subscribe
to the channel for new videos every week. Until next time, I’m Mike Armstrong. I’ll see you down the line! Thanks for watching.

About the Author: Michael Flood


  1. Some very rare locomotives are:

    0-8-2 Kado (Sometimes Queen Mary)
    0-8-4 London
    0-10-2 Union
    0-4-2 Olomana
    4-4-4 Julibee
    2-4-4T Boston
    6-8-6 PRR Turbine
    0-10-0 (also) Union
    4-10-0 Gobernador
    2-6-8-0 (no name but used in US)

  2. How can a steam locomotive run with a diesel, like with that metrolink you were showing? It just seems like it'd be different.

  3. Hey CoasterFan2105 I know this on a different video but do you know how much longer the F59PHIs on Amtrak Surfliner are supposed to be around because I got some information about all of Amtrak's F59PHI fleet was sent to the east for a rebuilding program and you said in the Siemens Charger video that there are still more Siemens Chargers on order for California and some of the other states but do you know though let me know!!!!….. (: 🙂

  4. Wow another great video you know how I love the steam trains but I not only about the steam train but by the wheel arrangements now I know how to tell what it is so thanks for that that is something I have always wanted to learn thanks for teaching me I learned a lot now I will be practicing on every train I see LOL well the ones I can practice on lol thanks again I will have to watch this video again just to make sure i have this down!!! 💖🚂🚂

  5. We Have D52 Locomotive, It's Mikado From Indonesia

  6. C53 Is Indonesian Pacific

  7. B51 Is American From Indonesia

  8. Hi Mike / I think, I scored 100%. 😎 I did not chew any gum in your class! lol
    • Cheers from The Detroit Mackinac Railway • Pronounced: (mac-in-aw) 🚂

  9. Pilot wheels are also called bogie wheels. That was the name I learned and read about regarding wheel arrangements.

  10. Speaking of Tank Engines,Another Wheel Arrangement for Tank Engine's is a 0-6-0T which was An LB&SCR E2 class locomotives which was based on Thomas The Tank Engine.

  11. Coasterfan2105 could you do a train talk on the Amtrak LRC….. if you need any info ive looked into the more successful VIA LRC!

  12. Hello 🙂 can you do an Electric Trains Galore? That would be really awesome 😀 I'm from Germany and I watch your videos almost every day when I have the time. Keep up the good work!

  13. Does the U.S. (Specifically Union Pacific) have a lot of Tank Engines? I know of plenty of Tank Engines in the U.K. just not brushed up on any here. It doesn't seem like we have a lot in the way of small engines, lol.

  14. Very cool video CoasterFan2105 , nothing like the power steam i spent time at the throttle of a famous steamer

  15. I know you just mentioned the 4-8-8-4 "Big Boy" type at 8:07, but I believe you forgot 8 more. You forgot the 4-8-0 "Mastodon" type, the 4-8-2 "Mountain" type, the 2-10-2 and/or 2-10-4 "Texas" type, the 2-6-6-2 and/or 2-6-6-4 "Mallet" type, the 2-6-6-6 "Allegheny" type, the 2-8-8-4 "Yellowstone" type, and the 4-8-8-2 "Cab Forward" type.

  16. +coasterfan2105 that would be funny if you did a train talk of my series rails of Sherman hill ts series

  17. My son Zach (age 8)loves your videos! Thank you for doing them! He got 3 of them right.

  18. Sorry if i am Being picky but Pacific that had been given from New Zealand R class of 1901

  19. I really enjoy your train talk videos. Keep up the super work! 🙂 *p.s. I missed one! Rats!

  20. Lol I love steam engines, but where I live, we don't really have any… BUT back in April, Union Pacific 844 actually came out here to celebrate the Boise train depot's 92nd birthday. And it was absolutely GLORIOUS!!

  21. Question. What is the designation for this locomotive. 2 – 8 – 0 but the 1st set of drivers is separated from the latter 3 sets by maybe half the dia of the driver? I found a picturw but the link is too long to post (????) google IC locomotive 638 Drop down the the line of pictures and click on the 3rd pic (I.C.R.R. engine 638). Could this be the source of that line in the Casey Jones song about the "6 8 wheeler"?? (along with literary license lol)

  22. My favorite is the 4-6-0 ten wheeler especially narrow gauge ones btw the 2-8-4 doesn’t just have one name they were called big Emma’s by the L&N ,Kanoaws by the C&O ,S-1 by the Pere Marqette and one road (can’t remember the name of it) called them big mikes

  23. Duplex and triplex locomotives use the Whyte system as well. The Triplex is basically an Articulated or Mallet type, with yet another set of driving wheels. The duplexes, ironically, are different from the three previous types, as while they have two sets of driving wheels, they sit on a rigid frame. Articulateds, Mallets, and Triplexes have a frame which is hinged to pivot (like pilot and trailing wheels) one of the driving sets to get around sharp curves using a longer locomotive

  24. I will do films to the steam engines that follow the whyte classification system and even the steam engines that don't follow it. Most of the locomotives that don't have the whyte classification system that I would film are the geared locomotives. But a little for the cog steam engines. The cog steam locomotives that I will film are the pikes peak cog railway steam locomotives.

  25. Wonderful video with practical examples!

    You would think that the numbers are always even – so the Whyte notation seems inefficient. Mr. Whyte could have halved the numbers, making counting wheels just on one side of the engine simpler and less error prone. However, there are examples of monorail locomotives… at least for the driving wheels which used a central rail. One such was Patiala State Monorail Trainways whose designation is 0-3-0. One driving wheel per axle. It's the only example of an odd-number in the list shown in Wiki's "Whyte notation"

    In another monorail where the notation becomes problematic is for Listowel and Ballybunion Railway. It was 0-6-0 but Wiki acknowledges "strictly speaking, 0-3-0".

    If monorail locomotives had an even number of driving wheels then we'd be back to confusion. From the notation alone there would be no way of telling whether it was a monorail design as it would more likely be mistaken for common 2-wheeled axles.

  26. Hi Mike, Mike here, my neighbor got me involved with youtube locomotives, it is mind blowing and awsome, I am in my seventies so you know what erea I belong to. My father worked for the NewHaven and Hartford and his last road was Erie…We lived close to the yard and I would listen to the locomotives hissing all night…. Thanks

  27. You missed the 2-6-2 prairie, 2-6-0 mogul , 4-8-2 mountain, 4-4-2 atlantic, 2-8-4 Berkshire, 2-8-8-4 Yellowstone , 2-10-0 decapod, 2-10-2 Santa Fe and 4-6-4 Hudson. You missed other wheel arrangements I don't know the name of but these are the 4-8-0, 4-6-0 and 0-4-2

  28. Found you via google search on loco wheel count, and thus the info video. Your narration was really nice. I learned a lot… except there was no mention of a 4-8-2 “Mountain” which is on display near me. In 1926, SLSF (Frisco) railway purchased these locomotives from Baldwin Locomotive Works. Will keep up w/your posts! Railfan in MS

  29. Also Atlantics(4-4-2) Mountains(4-8-2) Decapods(2-10-0) Santa Fes(2-10-2) Alleghenys(2-6-6-6) 2-8-8-8-2(Triplexes)

  30. Fun fact: During WWII, Americans replaced 2-8-2 "Mikados" with "MacArthurs" bc Japan was our enemy at the time!

  31. Where are the atlantics (4-4-2), columbian (2-4-2), decapod (2-10-0 / 0-10-0) and mountain (4-8-2) type steam locomotives

  32. Would have liked to have seen mention of the European systems of specifying wheel arrangement. The old one (not sure of the original name) is like Whyte notation but counts axles (or the wheels on just one side), and omits the hyphens. The newer one (not sure of the original name) used letters for groups of driving axles and evolved into the modern wheel arrangement systems (AAR in North America and UIC in Europe — not sure which ones are favored in Asia, Africa, and South/Central America). Both Whyte and the other systems had to be extended to accommodate articulated locomotives.

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