Last updated on January 7th, 2025
Probably the largest locomotive ever in use, a Union Pacific Big Boy steam engine is a sight to behold. I saw Big Boy 4014 in Minnesota 2019. But you can see one for yourself as Big Boy 4014 takes a tour of the west between it’s home in Cheyenne and Omaha in summer 2023.
The Big Boy is again on tour in late summer 2023. See the full schedule on the U P Steam website.
Union Pacific celebrated the Transcontinental Railroad in a big way
2019 was the 150th anniversary of the completion of the Transcontinental Railroad.
In a decision that seems to have surprised even the biggest railfans, the Union Pacific railroad celebrated their role in building the Transcontinental Railroad by resurrecting one of their legendary Big Boy locomotives.
Two 19th century railroads raced to unite the nation (and make a lot of money)
In order to connect the vast distance between the developed east and the California coast, Abraham Lincoln signed the Pacific Railway Act in 1862. This law authorized the Central Pacific railroad to construct a rail line eastward from Sacramento, California, and the Union Pacific to build west from the Missouri River until the two lines met. With thousands of acres of land and dollars riding on every mile, the race was on.
Seven years later the two railroad tracks met at Promontory Summit, Utah. On May 10, 1869, it became possible to cross the nation by rail.
As for the competitors in this great race, not only is the Union Pacific is still in business, but it’s one of the largest and most successful railroads in the country. On the other hand, Central Pacific ceased operating independently in 1885. Today its original right-of-way is controlled by Union Pacific. This seems to make UP the ultimate winner of the 19th century challenge to connect the country via rail.
No wonder they were looking for a big way to celebrate.
UP needed big locomotives as World War II approached
With war in Europe, US manufacturing came charging out of the Depression to build machinery, weapons, and other goods needed in Europe.
With a few particularly challenging mountain lines among their routes, Union Pacific needed exceptionally powerful engines to the haul heavy loads moving to, from, and between US factories. To meet the demands of a nation on the verge of war, UP had a new class of locomotives designed and produced specifically to haul heavy loads through the mountains.
Built by the American Locomotive Company of Schenectady, New York, the locomotive got its name when an unknown worker took a piece of chalk and tagged the first one “Big Boy.”
The name fit. And it stuck.
Each of these coal-powered behemoths was 132 feet long and weighed in at 1.2 million pounds. Because of their great length, Big Boys were articulated (hinged) with the two engines being able to turn independently of each other and the chassis on curves. (The “engine” on a steam locomotive is the truck assembly with the steam charged cylinders, pistons, connecting rods, and driving wheels). They were the only steam locomotives built in a 4-8-8-4 configuration, with a four-wheel guide pilot up front, eight wheels driven by the two steam engines, and a four-wheel pilot under the cab.
(You can see how this all fit together on this cut-away illustration by Donn Thorson.)
With up to 7,000 horsepower available, a UP Big Boy locomotive could haul a 4,000-ton (8-million pound) train over mountains between Odgen, Utah, and Cheyenne, Wyoming. Of course, to do that the locomotive went through 28 tons of low-grade coal and 24,000 gallons of water every few hours.
Once out of the mountains, the enormous engine could ran fully loaded at more than 50 miles per hour.
The life, death, and resurrection of a Big Boy
Union Pacific had 25 Big Boys, with unit numbers 4000 through 4024. They came in two batches, the first 20 arrived in 1941. Five more came on line in 1944.
Big Boy 4014 was delivered in December 1941.
It seems to have had an uneventful career hauling freight over the Ogden-Cheyenne line exactly as it was designed to do. Over its working life, Union Pacific 4014 traveled more than a million miles.
But 4014 and the rest of the Big Boy steam locomotives were among the last of their kind.
More efficient and easier to maintain, heavy duty diesel-electric locomotives were hard at work by the end of the 1940s. Indeed, UP intended to start using to diesels in 1944, but war-time restrictions left them ordering those five extra Big Boys instead.
When the war ended, railroads updated their fleets with the new diesel-electric engines. But UP, with a fleet of modern steam locomotives and their own source of coal, was slow to make the switch.
UP Big Boy 4014 made its last working run in 1959. Like other Big Boys, Union Pacific stored it for a few years just to be sure the new electric locomotives could handle the demand placed on them. They could.
In 1961 Big Boy 4014 was officially retired.
By 1962 all 25 Big Boy locomotives were retired and the process of scrapping them was underway.
Resurrecting a Big Boy
Even though diesel-electric locomotives are more preferable from an operations standpoint, the big steam engines are sentimental favorites. However, despite their popularity, only eight Big Boy locomotives avoided the scrap yard. All eight left Union Pacific for parks and museums across the country.
But it isn’t easy to preserve a 132 feet long object that weighs over a million pounds. A fact Union Pacific discovered when they began searching for a Big Boy to restore and operate.
None of the eight remaining Big Boys had operated since leaving Union Pacific decades earlier. A couple were in good enough condition UP steam experts thought they could be restored. But Big Boy 4014 was the top choice.
Big Boy 4014 had a few things going for it. From the very beginning it was in better shape when it left Union Pacific than some of the locomotives sent to museums. Once it arrived at the RailGiants Train Museum in Pomona, California, it was lovingly cared for by members of the Southern California Railway and Locomotive Society – who always hoped their locomotive would operate again one day. To be ready for that possibility, they carefully prepared the engine for display and regularly maintained it during its decades on display. The critical factor was the condition of the boiler. With the tremendous amount pressure created by a steam engine, a solid boiler was essential. And Big Boy 4014 had the best boiler of all the remaining locomotives.
In 2013 Big Boy 4014 moved out of Pomona. With plenty of stops along the way, diesel engines slowly rolled the old steam locomotive to the Union Pacific steam shop in Cheyenne, Wyoming.
Once there, restoration process began.
A new old locomotive
Original blueprints and modern computer technology were combined to ensure the best rebuilt locomotive possible. The entire engine was taken apart, pieces were inspected and repaired or replaced, and then the whole thing was put back together again.
With better materials and technology available today, much of Big Boy 4014 is new. But the most significant change was in the locomotive’s fuel source. The dirty, coal-fired system that consumed tons of fuel and thousands of gallons of water was replaced by a system that burns a type of heavy fuel oil. As it burns, it creates the heat needed to form steam to power the massive engine. But it’s both cleaner and more convenient than the soft coal Big Boys were designed to burn. Nor is it unusual. From the 1930s on, several other railroads converted to oil-fueled fireboxes.
In May 2019, Big Boy steam engine 4014 moved out of the Cheyenne shop under its own power. The first time a Big Boy moved under its own power in almost 60 years.
Big Boy 4014 goes on tour
To celebrate the 150th anniversary of the Transcontinental Railroad, Union Pacific sent Big Boy 4014 on a tour of the UP rail system in 2019. That tour included a summer race across the Midwest followed by a race across the Southwest.
On tour, the restored steam engine hauled a diesel-electric locomotive. That diesel engine wasn’t pushing Big Boy 4014, but it did provide most of the Big Boy’s braking. Stopping a big heavy engine, even if it isn’t pulling a lot of weight, puts a lot of wear on the brakes. Using the diesel locomotive’s regenerative dynamic and common service brakes prolongs the life of 4014’s custom-built brakes.
The Big Boy steam locomotive also pulled support cars, historic 1950s-era passenger cars (besides the crew, a few UP executives and passengers travel with the train), and the Experience Union Pacific Rail Car. The train that came through the Midwest included the following:
- Water tenders 809 and 814, the Jim Adams and Joe Jordan, from 1937, which were converted to fuel tenders and then back to water tenders over time
- Diesel-electric locomotive 3025 – SD70AH-T4
- Tool car 6334 – Art Lockman, a 1962 baggage car converted for use as a maintenance tool car
- Boiler car 209 – Howard Fogg, a 1949 baggage/dormitory car converted to various types of boiler cars over time
- Baggage car 5714 – Lynn Nystrom, originally a 1957 postal storage car used to store supplies
- Dome coach 7015 – Challenger, it as the last of it’s kind when it was built in 1958
- Experience Union Pacific 5752 – Promontory, an exhibition space with historic photos and displays on the transcontinental railroad, locomotive technology, modern rail transport, and more
- Deluxe sleeper 1602 – Green River, built in 1949 as a 12 roomette, four-bedroom sleeper car
- Power car 2066, a converted postal storage car
- Dome lounge 9005 – Walter Dean, built in 1955
- Diner 5011 – City of Denver, built in 1959 as a lunch counter cafe and lounge
- Business car 119 – Kenefick, a 1950 coach car converted to a business car in 1963
Detailed information on UP historic equipment and steam locomotive support cars (PDF) is on the Union Pacific website.
The 2019 tours offered opportunities to see the Big Boy train both in action and at rest.
While on tour, online maps show Big Boy 4014’s route, current location, and planned stops. While most stops are very brief (15-30 minutes), a few longer ones allow the public to see Big Boy’s cab and visit the Experience Union Pacific exhibition car. The UP Steam Twitter feed sometimes provides up-to-the-minute information on the status and exact location of the train.
The Great Race across the Midwest
I saw Big Boy 4014 several times along its route through Minnesota and Wisconsin in July of 2019.
As in other places, when the train stopped in a location open to the public, it was usually only for very a brief whistle-stop. The two stops where the public could actually get a really good look at the locomotive and enter the exhibition car were in Saint Paul and Duluth.
Of course, the train was also visible from many locations and crossings as it raced through the countryside!
Big Boy 4014 on display in Saint Paul
Saint Paul, Minnesota, was one of the stops on Big Boy 4014’s 2019 tour of the Midwest. Here the locomotive spent a day on display at the Union Depot.

Union Depot Saint Paul, Minnesota, announcement for the 2019 Big Boy tour
As seems to be the case everywhere the Big Boy locomotive stops, it drew massive crowds. In Saint Paul, crowding and confusion intensified when Amtrak’s Empire Builder passenger train arrived (hours late) across the platform. But it was interesting to get a good look at the steam engine. And those willing to wait in line got to go up into the cab and/or through the Experience Union Pacific car – both of which would have been interesting.
And, even though the crew was busy with maintenance while the locomotive was on display, they took time to answer a lot of questions!
A whistle-stop in Baldwin
Even though the whistle stops were really short, I knew there would be crowds. Still, I was surprised by the number of people who showed up on a Tuesday morning in Baldwin, Wisconsin, to see the Big Boy during its brief stop.
Even though the stop was only for 15-20 minutes, it was a great way to see the locomotive. In Saint Paul, where it was parked on the track for many hours, 4014 was a more of really big, interesting object. Here it’s a living, breathing creature.
When the train stops, the locomotive continues running in order to maintain pressure in the boiler. It’s idling like the engine in a car, but this engine is more than a million pounds of hot metal breathing steam. Heat radiates from the locomotive.
It’s not so hot you can’t get near it, but definitely hot enough you don’t want to lean up against it. Along with the heat, the air is moist with steam and the smell of hot grease. Lubricants seem to drip from everywhere on this huge sweaty beast.
But people swarm around it anyway.
(The train had already come to a stop and was just moving forward a bit during a quick lube job. Still, it’s never a good idea to stand in front of a humongous steam engine while it’s operating!)
Along the route
Of course, looking at a stopped train is nothing like having a steam locomotive roar past at full power.
For that experience, you need to find a spot with a clear view of the tracks. It needs to be close enough to the track to feel the air pressure change as the engine goes by, but not too close. (UP requires the public stay at least 25 feet from the track. That’s plenty close. Besides, the Federal Railway Administration deems being any closer than that both potentially hazardous and trespassing.)
It’s best to find a spot where you can see the train from a distance as it comes around a curve, like this crossing near Lake Elmo, Minnesota.
Other people were also looking for good spots to watch this historic train race by.
But I found a few spots where I didn’t have to share Union Pacific 4014 with too many other people as it rolled past.
The Big Boy 2023 Tour
Big Boy 4014 is back on tour this summer traveling through Wyoming and Nebraska.
As with the 2019 tour, most stops are short, but there are a few places where the public will have a chance to take a good long look at the locomotive and visit the Union Pacific exhibition car.
The Big Boy train schedule is available at 2019 Union Pacific Steam Schedule. For more detailed information on the train’s specific location, check the Big Boy 4014 tracker.
Tips for safely viewing this, or any other steam locomotive, are also posted on the UP Steam pages.
Future tours
If you miss this year’s tour, don’t despair. The amount of money Union Pacific spent restoring Big Boy 4014 and its popularity likely guarantee future tours.
Keep an eye on the UP Steam page for upcoming events.
If you are a true railfan, join the UP Steam Club for more timely updates and insider info.
Big Boy 4014 isn’t the only UP steam engine still running
Big Boy locomotive 4014 is part of UP’s Heritage Locomotive Fleet. That fleet includes a mix of steam and diesel locomotives, all of which are operational and occasionally tour. It also includes a variety of other historic equipment, including passenger cars used for this summer’s tour.
Union Pacific didn’t keep any Big Boys when it retired its steam fleet. However, they kept one Northern class steam locomotive (and one for parts) to operate as a goodwill ambassador. Largely used for passenger service, the Living Legend Northern 844 was the last steam engine built for UP. It’s still used for special excursions.
It appears UP is also planning to restore another steam locomotive, Challenger 3985. Expect to hear more about that once Big Boy’s tour ends.
Check UP’s Heritage Steam page for future events featuring Big Boy 4014, Living Legend 844, or (maybe) Challenger 3985.
Where to see a Big Boy when 4014 isn’t on tour
When it isn’t touring, Big Boy 4014 is usually housed (stabled) at the historic Union Pacific Roundhouse in Cheyenne. This is a working facility that is only open for public tours once in May of each year. That limited schedule means 4014 usually won’t be on view unless it is touring.
However, seven other Big Boys are always on display. You can’t see or hear them in operation, but you can marvel at their size.
- Wyoming: Big Boy 4004 (the fifth Big Boy built) is on display at Holliday Park in Cheyenne.
- Colorado: Big Boy 4005 is on display inside the Forney Museum of Transportation in Denver. This Big Boy has a more interesting history than most, as it was temporarily converted to burn oil when coal miners threatened to strike and, later, was involved in a fatal derailment.
- Missouri: Big Boy 4006 is outside the Museum of Transportation in Saint Louis.
- Pennsylvania: Big Boy 4012 is on display at the Steamtown National Historic Site in Scranton.
- Wisconsin: Big Boy 4017 is on display inside the National Railroad Museum in Green Bay. It’s said to be one of the most complete Big Boys on display.
- Texas: Big Boy 4018 is displayed at the Museum of the American Railroad in Frisco after many years on display at the Dallas fairgrounds.
- Nebraska: Big Boy 4023 is on display in Kenefick Park at Lauritzen Gardens in Omaha, Nebraska. It was moved there in 2005 after undergoing a cosmetic restoration. It is easily seen when driving west on Interstate 80 upon crossing the Missouri River into Omaha.
The Union Pacific Railroad Museum is located in Council Bluffs Iowa. It does not have a Big Boy, but it does have photos and artifacts covering more than 150 years of railroad history.
There are other steam locomotives around too
Steam locomotives are actually fairly common. They are found in museums and displayed in parks across the country. And a surprising number still operate as excursion trains.
A webpage mapping surviving steam locomotives in the USA has a state-by-state listing that includes the status of each locomotive, a link to some of locations where they can be found, builder information, photos, and notes on condition and history. I don’t know how often (or recently) the site is updated – there are some bad links. But it’s a good place to start if you are looking for steam locomotives on display or operating near you.
Steam Railroading has a page on operational steam locomotives in the USA. It’s not as easy to search, but it has a lot of information about the locomotives listed.
RailServe’s up-to-date list of railfan events and train excursions seems to cover special tours using both steam and diesel locomotives, but there’s a lot of steam on the list. They also have a list of tourist railroads, museums, and train excursions that includes regularly scheduled tours with both steam and diesel engines.
Resources for additional information
Information on the Transcontinental Railroad:
- History.com has a very readable account of the race to build the Transcontinental Railroad.
Information on Big Boy 4014:
- Find all the locomotive’s stats on the Big Boy 4014 webpage.
- Union Pacific has a series of You Tube videos that cover the entire restoration process.
- The Wikipedia page on the Union Pacific 4014 has an impressive list of up-to-date resources with information related to Big Boy 4014.
- The Southern California Chapter of the Railway and Locomotive Historical Society has several pages on Big Boy 4014. (Sound alert: the webpage makes train sounds as soon as it opens.)
- Popular Mechanics explains Why the Big Boy 4014 is such a Badass Train.
- Atlas Obscura has a great story on Ed Dickens, the man who led the restoration of Big Boy 4019 and is now in the engineer’s cab taking it around the country on tour.
Big Boy souvenirs and other steam train treasures
Whether or not you actually see Union Pacific Big Boy 4014 this year, you can always add a few steam train themed treats to your collection or that of someone you love.
It’s A shame it can’t tour the eastern corridor, there’s A lot of railroad fans around here as well.
UP doesn’t have track east of the Mississippi. To make this work, they not only rescheduled traffic on their own track to accommodate the steam tour, but they also had to coordinate with BNSF on some segments. All that requires both cooperation and money. Sorry, but doing a tour on a lot of track UP doesn’t own seems unlikely. You need to get an eastern railroad to do a similar run!
I am from Scranton Pa
Which has a big boy at SMHS
What a machine they had it parked on Nicholson Viaduct largest concrete arch bridge in the world.
That seems like a pretty dramatic spot to show it off! I know they had brought it for some restoration work the other year — I thought they were still working on it. is it back on display now?
My husband saw the Big Boy 4014 while coming home from work. The Big Boy went through
West Chicago, Illinois on the way home from work. Steam Engines are wonderful to see. Besides vessels, they are the first major transportation we had. Tracks were wood, then iron, and then to steel. Steam Engines were able to roll on steel plates better than wood or iron.
Yes, steam trains were the cargo ships of the land. The American West never would have developed so fast or in the form it did without them.
Restore 4018 the one in Frisco TX. It technically has the lowest hours. When it was on display just outside the Cotton Bowl in the 60’s I used to marvel at its size. I was 10 years old. I’m 65 now. I always felt sorry for it as the huge drive arms were cut at the wheels, hobbled for life. With 4014 now restored my childhood dream of seeing 4018 might run someday too. But I’m running out of time.
No it not the largest..the PRR S1 duplex was the largest steam locomotive that was built…but the big boy is the largest production steam locomotive that was built.. PRR S1 was a one off prototype that was built and shown at the NY world’s show fair..1939…..The S1 was the largest passenger locomotive ever constructed, with an overall length of 140 feet 2 1⁄2 inches (42.74 m). At 77 feet (23.47 m) long and a weight of 97,600 pounds (44,300 kg; 44.3 t), the cast steel locomotive bed plate made by General Steel Castings was the largest single-piece casting ever made for a locomotive.
Yes, you are correct. The Big Boy was only the largest steam locomotive actually in use. But it was still pretty big!
did they restore the white steam away? all i saw was black diesel smoke coming out of it.
Haha. It may be hard to believe, but 4014 today runs on #5 fuel oil, which is cleaner than the soft Wyoming coal it was designed for and ran on during its life in regular service. The supporting diesel electric engine is only used for breaking, so, under power, the black smoke is from the converted coal – now fuel oil – engine. I did see some nice white steam released when it was standing still and idling, but not clouds of it. Steam locomotives were always dirty machines to run, so a trail of black smoke was normal.
How bout a northeast run back to Schenectady where it all began? I think that would be great as a railman and my son who loves steam engines as well.
That seems appropriate and would be cool, but UP doesn’t have track east of Chicago, so probably not very likely. (It appeared there were a lot of scheduling challenges just traveling on UP’s own active freight rails, not mention shared rail.) But who knows? Maybe someday. They did have a 2020 season planned, but, like so much else, it was canceled. Keep an eye on the UP Steam web page to see when they announce plans for 2021.
The big boy 4014 is my most favorite steam engine, I had ever seen, in my life, and I am 35 years old
I really like steam trains, and I really wish there are steam trains to go through Claremore Oklahoma and across Claremore Oklahoma, even with passenger cars hooked up too
Maybe some day. You certainly aren’t the only one who likes trains!