Farm Collector

Model Steam Engine Scaled to Perfection

The scale model steam traction engine that Tom Nichols helped the late John Shepherd build is a testament of the respect, love and friendship that he had for his friend.

Tom describes it as a labor of love, love that flowed in several directions. John intended the project as a memorial to his father, who once owned an 18 hp Wood Bros. steam engine; for Tom, the project grew out of his love for his friend. “John wanted it, and he was an old man,” he says, “so I thought, ‘I’ll help him get his dream.”

And then there was John’s love for Tom, as they spent every Sunday morning for two years together, starting as early as 6 a.m., and going five hours or more, working on the 5/8-scale Wood Bros. steam traction engine.

Planning the project

The idea to create a scale-size Wood Bros. steam traction engine developed on a rainy day in 2000, when the two men were driving through Davis County, Iowa. “John was in his late 70s,” Tom says. “By that time he and I had become really good friends, because I had bought his full-size Wood Bros. engine (serial No. 426). We were driving around the countryside where he grew up when he said, ‘If I had a boiler, I’d build a model steam engine.’ I said, ‘Shoot, John, it would be pretty easy to find a 16-inch boiler to build a half-scale model.’ John said, ‘No, I want to build a 5/8-scale.”

Tom did a few quick calculations in his head, and said that meant a 20-inch tube, and he didn’t know where to come up with a tube for that. “That pretty well ended that conversation,” he recalls.

Answers sometimes come in their own ways. Later, at a steam show, Tom asked Bob Thomas (owner of a 1/2-scale 32 hp Reeves steam engine) where he’d gotten his 20-inch diameter tube. “He told me who to contact, so I called Craig Pipe Co. and asked, ‘You wouldn’t happen to have a 20-inch piece of pipe for a boiler?’ He said he had brand new stuff sitting right there.”

Tom didn’t waste any time sharing the news with John. “John could be a grumpy old man at times, but when he heard I’d found that 20-inch pipe, he was very excited,” Tom says. “When we went to get that 20-inch pipe, he had a little sparkle in his eye.”

Keeping it close to home

By the next Friday they’d picked up the pipe in Ridgeway, Missouri. “John just needed a little help getting going on it,” Tom says. “After that, we spent a couple of years gathering parts and building on the boiler.”

Once they had the boiler pipe, they began measuring Tom’s 22 hp Wood Bros. engine and scaling the figures. They discovered what they’d already suspected: In scale models, things don’t always work perfectly, because you can’t always scale things down exactly, like the stay bolt pitch, flue tubes, valve motion and water leg around the firebox.

They bought a couple of sheets of 3/8- and 1/2-inch commercially available steel to use in constructing boiler components. “We cut the steel and had the wrapper sheet rolled, and then the firebox flue sheets and crown sheet were cut out and holes drilled,” Tom says. “Then we formed the crown sheet ourselves.”

Then they started to tack-weld pieces together to be sure things fit and that they were on the right track. “After that, we popped the firebox out and, with a lot of other preparation, welded it solid, because it worked,” Tom says. “We welded the wrapper sheet to the boiler tube, welded on the steam dome and then dropped the firebox back in and welded in the mud ring, and started putting in stay bolts, using 3/4-inch hot-rolled round stock. The stay bolts tie the outside boiler sheets and firebox sheets pieces together.”

After they finished the boiler, they built engine components, wheels and brackets and smoke box door, and made patterns for the flywheel, crank disc and smokestack and had them cast. One was poured unsuccessfully three times, so they fabricated the cylinder and tunnel from scratch. John also made a pattern for a steering wheel and its spinner handle.

“It became kind of a joke between us,” Tom recalls. “I wouldn’t say that it was a low-budget operation, but we were very conservative in what we hired and what we did ourselves. Other than machining the flywheel (due to its size), we did all the machining work ourselves.”

Gathering parts and pieces

Several parts on the 5/8-scale model were sourced from various pieces of farm machinery. The steering worm and worm gear are from a Farmall F-20. The bull gearings and pinions and differential gear are from a Farmall F-30, and are mounted into a differential gear from a John Deere Model A.

The crankshaft gear is from a John Deere 70, while other parts (like the steering chain for the front axle) were formed from simple hardware store components. John fabricated shackles and corner brackets for the rear axle and countershaft. “We basically scavenged parts all over the Midwest,” Tom says with a laugh.

Boiler fabrication, along with the engine cylinder/tunnel, was done in Tom’s shop. “John bored it at home on his lathe, an old 12-inch Clausing lathe with no power feed on it,” he says. “He sat there and worked on it for two or three days. But a lot of really nice models have been built over the years with just a hacksaw, file and electric drill. It’s amazing!”

Wood Bros. built by “Nichols and Shepherd”

The pair started work on the engine in early July 2000. They finished it four years later, building a fire in it for the first time in June 2004. Not everything went perfectly; the biggest problem was getting the valve motion right. “We didn’t get enough throw into the eccentric,” Tom says. “To compensate for that, we elected to tweak the rocker arm to get our valve motion correct.”

Before they ran the scale model, they hydro-tested it to 1-1/2 times the operating pressure of a 150 psi and held it for a length of time to make sure there were no leaks or problems.

“Building that 5/8-scale engine made us feel good,” Tom says. “We accomplished something. There were times when we thought we would never get it done, but we struggled through and we finished it. Afterward we kidded that it took a Nichols & Shepherd to build a Wood Bros. engine,” he says with a laugh.

True to the original engine

Running a full-size steam traction engine is different than running a scale model. “A full-size engine fires a lot easier,” Tom says. “This 5/8-scale model has a nice big firebox door, 2-inch-diameter flue tubes, and grates with a lot of air space for air to get through.”

Other scale models are easy to over-fire, but that doesn’t seem to be an issue for the scale-model Wood Bros. engine. “Every fire is different,” Tom muses. “When you strike a match and throw it in the firebox, you don’t know if it’s going to take right away and steam in an hour and a half or so, or whether you’ll have to work at it and wait up to two hours. It all changes if there’s a good breeze, or moisture in the air, or if the kindling wood is good and dry. The way I was taught, if you could run a model steam engine, you can run a full-size.”

Besides the size and the name, other features of the 5/8-scale model are exactly like the full-size 22 hp Wood Bros. engine. Take the step plates used to get up onto the scale model. “The top plate shows ‘Wood Bros.,’ just like on the full-size engine, and the lower one says ‘Good luck,’ again like the full-size Wood Bros. engine,” Tom says. “I don’t know how it can say ‘good luck,’ because those plates are always oily and that makes for an exciting time, climbing up on them.”

The best accomplishment

John died in 2015 at age 89. “He was a very intelligent man with only an 8th-grade education,” Tom says. “He was a natural, with a lot of talent. He read books to figure things out. He grew up in the 1930s and ’40s, when people did a lot with nothing. And you have to have a lot of respect for them.”

Well into his 80s, John knew where every surviving Wood Bros. steam engine was — and its serial number. “John grew up around steam, and especially around Wood Bros. engines,” Tom says, “and that created a passion for him.”

After selling his last full-size engine, John said he would never return to the Old Threshers reunion as an exhibitor, but the scale model engine the two men built pulled him back. “And that was a big deal,” Tom says. “But the friendship that John and I had, that was the best accomplishment of all.” FC

For more information: Tom Nichols, 2707 Ash Ave., Eldon, IA 52554; (641) 919-5280; email:

Bill Vossler is a freelance writer and author of several books on antique farm tractors and toys. Contact him at Box 372, 400 Caroline Ln., Rockville, MN 56369; email:

  • Published on Sep 4, 2018
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