One of the World’s Largest Steam Locomotives Is About to Make a Triumphant Return

Atlas Obscura ^ | 06/12/18 | Justin Franz

[Simon Green]

Hold onto your engineer caps, railroad history lovers.

Seventy years after the First Transcontinental Railroad was completed in 1869, the steep Rocky Mountains of Wyoming and Utah were still giving the Union Pacific Railroad trouble.

Despite having massive steam engines, the Union Pacific, one of the biggest railroads in America, still struggled to move heavy freight trains over the mountains and would often have to use multiple locomotives to get trains to their destination. This practice required more workers and more fuel. In 1940, the Union Pacific’s mechanical engineers teamed up with the American Locomotive Company to build one of the world’s largest steam locomotives, a class of engine simply known as “Big Boy.”

Now, six decades after the last Big Boy was taken off the rails, the Union Pacific is rebuilding one of the famous locomotives in honor of the upcoming sesquicentennial celebration of the first Transcontinental Railroad. It’s a project so ambitious that Ed Dickens Jr, a Union Pacific steam locomotive engineer and the man leading the rebuild, has likened it to resurrecting a Tyrannosaurus rex.

The Big Boy locomotives weighed more than one million pounds and were 132 feet, 9 inches long. Stood on its end, one would be the equivalent of a 13-story building. Each one cost approximately $265,000 to build, or about $4.4 million in today’s money. In the railroad world, the Big Boys were known as 4-8-8-4 articulated type locomotives. That designation meant the locomotive had four wheels in front, two sets of eight driving wheels (the large wheels connected to the pistons that make the locomotive move) in the middle, and four trailing wheels, all underneath one enormous boiler.

[mountn man]

https://www.youtube.com/watch?v=5i5pv-dLndc

This guy does an excellent homemade documentary

[marktwain]

If the Soviets and the Mediacracy had not ginned up so much anti-nuclear nonsense, we might have nuclear train engines by now.

[Mariner]

Does anyone know what the PSI rating was for those boilers?

I ask because I served on a Adams class Destroyer (DDG-22) and they were reputed to be the last of the 1200 PSI steam plants in the US Navy.

Invisible steam that could cut you in half if you walked by a leak.

[PhiloBedo]

As long as the engine is, if the wheels are not articulated, how does it go around bends in the track?

[TXnMA]

Circa the winter of 1959, I was privileged to see one of these 4-8-8-4s parked on a siding alongside the highway just west of Cheyenne, Wyoming. Truly an impressive hunk of iron!

[Hootowl]

Why rebuild it? I believe there’s one on display in the Denver Museum of Transportation. Just fire that sucker up!

[DUMBGRUNT]

horsepower and cylinder sizes were computed based on 300 psi boiler

https://store.steampowered.com/manual/208361

[Mariner]

But, a very big boiler and very big cylinders.

thanks for the info.

[South Dakota]

I think they had one in a chyenne park..efing thing was huge

[Kartographer]

Watching a giant Saturn V blastoff from the viewing area is a great experince, but it isn’t the same as having one lite-up and strapped to your ass! ;-)

[DesertRhino]

“If the Soviets and the Mediacracy had not ginned up so much anti-nuclear nonsense, we might have nuclear train engines by now.”

That is a borderline insane idea. The risks aren’t worth the benefit, and it is horrifically inefficient. To make use of nuclear power, you build nuclear plants to make electricity and run electric trains. One reactor could run a huge number of electric trains.
And remember, pretty much all trains after steam are electric. The Diesel engine merely spins a generator to make electricity. The Electricity powers the traction motors. The traction motors don’t care where the electricity comes from. Also, your atomic train would need to use steam to produce electricity. So you are back to some form of live steam.

[Bookshelf]

I too have unpleasant childhood memories of the sound made by locomotives as they drove east through the Sierra Nevadas from Colfax, California to Lake Tahoe. I’m not sure it was the same loco as the one described here, but in any case they were l-o-u-d.

[Capt. Tom]

Unless you are WALKING over the bridge and the train goes by——under the bridge. Dreadful.

As an old Savin HILL1 boy I used to see those locomotives coming and deliberately stand on the bridge with my friends as they passed under us.
That's gone now and the Southeast Expressway has replaced those tracks. - Tom .

[Midwesterner53]

Big railroad buff here, love stories like this.

[Midwesterner53]

Little known fact. When steam engines pulled passenger trains in the days before air conditioning, and trains were segregated in many areas of the country, black riders actually sat in the first cars, because with windows open and the close proximity to the engine, soot came in the windows more up front than in the back. So wanting to ride up front was not always a goal for African Americans until later.

[Bull Snipe]

Before the Big Boys, UP double headed Challenger engines to get trains up Sherman Hill and the Wasatch Mountains. Once the big boys became available, it took one Big Boy to make that run.

[Renegade]

No problem with 3d printing

[Verbosus]

Bookmark

[Renegade]

And u pooped right on the track Bed.

[Attention Surplus Disorder]

The wheels, of course, are mounted on individual carriages, which can swivel on central pins/bearings. But on the very largest of the huge UP engines, the front carriage could also slide side-to-side. The front half of the boiler on tight curves could be seen a few feet off the centerline of the front truck! You can see it starting 11:40 here https://www.youtube.com/watch?v=fXcD6ZdPR9k

As solid and imposing if not brutal as the giant UP engines were; to enable this, there was no mechanical connection between the cylindrical boiler and the rectangular frame for perhaps the first 20 or so feet of the engine’s length. (!)

You can see this on the UP 3985 Challenger footage https://www.youtube.com/watch?v=XRZ23VVQhwQ at about 3:55 (very similar engine) and at 18:15

Of course the most amazing shots are these 70 mph UP3985 tracking shots https://www.youtube.com/watch?v=ZVcOPIaekOU

A few of the early striking looking streamlined Pennsy engines (The S-1 and the T-1, I believe) were *not* articulated and could not make some of the approach turns into the Chicago station without damaging the rails. They were retired and scrapped only a couple of years after they were introduced.