The Union Pacific “Big Boy” No. 4014 locomotive, the world’s largest steam engine, rolled into Des Moines one day last week. After two years of restoration, the historic 6,000-hp engine is touring the Midwest as part of the 150th anniversary of the completion of the Transcontinental Railroad.
Big Boy arrived in Des Moines and parked south of the Iowa State Fairgrounds. A crowd was already waiting, and people kept coming all day to marvel at the historic train. Visitors could climb onboard some of the passenger cars Big Boy was pulling and tour the train museum inside.
Big Boy’s 20-year run
This Union Pacific steam locomotive was built in 1941 and was taken out of service in 1961. I can remember trains pulled by steam locomotives rolling past our farm in the mid-1950s. As a young boy back then, I recall my grandpa telling me, “It won’t be long until you won’t see these steam engines being used anymore. Diesel locomotives are rapidly replacing steam power.”
We saw perhaps 10 freight trains roll by our farm each day, and only two were powered by steam engines. The rest were diesels.
Last week John Otte, longtime economics editor for Wallaces Farmer, now retired, called asking if I wanted to go see the big steam engine that was coming to Des Moines. So off we went, driving to the fairgrounds on the east side of Des Moines. It was a popular exhibit, as people were flocking to see Big Boy. Parking was crowded. We, along with several thousand other people that day, got a glimpse of American history.
As John says, “We had a blast looking at the big engine and discussing how this giant mechanical marvel worked.” Yes, we had a blast. But they wouldn’t let us blow the whistle.
Giant size creates giant stress
By John Otte
Union Pacific information says the Big Boy locomotive alone stretches 85 feet long. The tender extends the unit to 133 feet. Combined, they tip the scale at over a million pounds.
Big Boy has a 4-8-8-4-wheel configuration. That means he has four small wheels under his front truck, two wheels on each side. The front truck helps guide the locomotive around curves. Next are eight 68-inch-diameter drive wheels under the front power unit. Then comes eight more drive wheels under the rear power unit. A four-wheel truck under the back of the engine helps support the firebox.
Making 24 wheels that are in two straight lines of 12 wheels each that are on a wheel base 72 feet long go around a curve in the railroad tracks puts a huge amount of side pressure on the wheels and an equal amount of stress on the railroad track.
Articulation an engineering marvel
Design engineers cut that side pressure in half by making a monstrous pivot point under the front of the boiler, so the front truck and front power unit move independently from the main frame. The ability to do this is called articulation. Some sizable four-wheel-drive farm tractors today use that feature for steering. Articulation allows a longer locomotive to negotiate tighter curves.
Letting big diameter rigid steam pipes bend as the front power unit pivots would soon result in pipe failure. You don’t want to have steam jetting at you at 300 pounds per square inch pressure.
The design engineers created a ball-joint in the pipe. It's a spherical two-piece casting that’s flexible yet fits together snugly to make a steam-tight joint.
Steam power on farm
Into my father’s time as a young farmer, farmers used steam power on their farms. Often the farmers in the neighborhood threshing ring jointly owned the steam engine used to power the thresher.
I remember my father telling how, as a kid, he held the lantern while his Uncle Louis tinkered inside the firebox inspecting for problems or making repairs. Obviously, the only fire that was in the firepot at the time was the fire in the kerosene lantern that Pa was holding.
The old-timers didn’t have sophisticated ways to test the boilers. Here’s how Dad explained it: At the front end of threshing season, Uncle Louis would put all the water in the boiler that it could hold. Next, he’d build a small fire in the firepot to slowly build the pressure up.
If a leak occurred, it would release a stream of hot water, rather than scalding hot steam. Pressure would soon drop. That was much less hazardous than having thousands of cubic feet of high-pressure steam coming at you.
Steam engines relatively safe
My father could only recall two major mishaps with farm steam engines. In one, the crew had moved from one farm to another. They backed the steam engine into the belt that powered the thresher and started threshing. The gauge showed they had plenty of water in the boiler.
However, the gauge malfunctioned and gave an erroneous reading. The Occupational Safety and Health Act was still decades in the future. No OSHA inspection for that rig. The boiler had a lot less water than the farmers thought and was a lot hotter than they realized. When they started to pump in water, it instantly turned to steam. Pressure shot high. The bottom blew out of the front end of the boiler. The jet of steam shooting down at the ground caused the engine to flip over on its back. The engineer perished.
In the other incident, the crew was moving from one farm to another, and the steam engine was towing the water tank wagon followed by the thresher. The steam engine proved to be too heavy for a bridge. The back end fell through, followed by the water wagon. Again, the engineer perished. Pa said his name was Lowell Koteman.
A near-death experience
Pa maintained that way more farmers got maimed or killed dealing with bulls, horses and other livestock than ever got hurt with steam engines. He was living proof.
The house yard on the homeplace had a picket fence on two sides. The picket fence had a gate. The gate opened outward. It was open. The young lad who was to be my father was standing on the outside. A team of horses bolted from the drive-through granary. They came racing around the corner pulling a high-wheeled wagon.
When the team and wagon passed, the gate was no longer attached to the fence. Had my grandmother not grabbed her son by the shirt collar and snatched him back into the house yard, Rod Swoboda would not have me helping him write this story.