He wound up with a Smithsonian fellowship in 1980 and took a job three years later in what is now the National Museum of American History. But it is industrial history, trains especially, that fascinates him.
"Who can say why people get into this. Steam is the land version of the clipper ship," says Withuhn. "It's such a pleasure to work with your hands. And you work with blue-collar people, which is so different from the rest of my world. When you're sailing, or flying planes, you're mostly with people of means. These are working stiffs."
It's been said that railroads are the veins and arteries of America, and Withuhn knows it's true. "As a green navigator in the Air Force I was flying over the Appalachians one day, and the pilot, this old-timer, says, 'Navigator, you know where you are? I do. That's the Big Bend Tunnel down there." Near Denver it was the Moffat Tunnel. Old pilots used rail lines like maps. The Iron Compass.
"Trains are more demanding than a plane or a big yacht," he contends. "A steam locomotive is like a rolling lit bomb. You have 200 pounds per square inch of pressure in the boiler, and if it goes up, the explosion can send the locomotive 300 yards down the track. You have this huge momentum, 1,000 tons behind you. You have to be ahead of it at all times. You need to know all the changes in grade and the curves and rail crossings."
Air brakes are a great invention, he says, but there is one problem: there is no way to let them up gradually. If you don't work it just right you will either stop before the station or go roaring past it.
"Also, you want to keep the train stretched, so the cars don't bump together. So you have to release the cars' brakes just so. In the old days they had guys on top of the cars turning their individual brake wheels."
The John Bull of 1831, the Smithsonian's oldest locomotive, had no brakes at all; they were only on the tender that carried the engine's fuel and water. A locomotive, the crewmen insisted, is for going, not stopping. It didn't have a cab to keep the rain off, either. Cabs were for sissies.
"Plus, it's a team thing. You're always working with your fireman," explains Withuhn. "If you're speeding up, you have to give the fireman time to stoke the fire, or let it die down if you're slowing. When the track curves to the left, the engineer can't see ahead, so the fireman does the looking.
"Oddly enough, it's the conductor, not the engineer, who commands the train," Withuhn continues. "It started with the early railroad men in the 1830s, maritime men. They saw a train as being like a steamboat, and they wanted a deck officer. To this day, it's the conductor who sets the train in motion with his signal.
"What makes industrial history important today," he says, "is that we need to be reminded that the people who built this country physically were blue-collar workers. Running a crack train at 90 miles an hour meant you had to think three miles ahead. These were people who never finished grade school, some of them, and they had many of the same skills and responsibilities as the captain of a 747 jet. An engineer with an oilcan was big stuff once — kids looked up to him. Like airline pilots, who had a certain cachet in the '50s, but whose status has eroded now. People worked without computers then. There was civilization before the computer: we need to appreciate that."