Meet Tom. Thomas H. Fehring, P.E., is a retired Milwaukee engineer who compiled the history of The Magnificent Machines of Milwaukee and the Engineers Who Created Them.

One of those industrial innovators was A.O. Smith, a company that once occupied a sprawling industrial campus south of Capitol Drive and west of Hopkins.

It was right here—across the railroad tracks from what is now Melvina Park—where the world’s first automated auto frame assembly line was created.

Known as the “Mechanical Marvel,” a team of A.O. Smith engineers—in 1930 there were an incredible 400 on staff—designed the robotic system that filled a factory with a complex array of riveting machines. In went sheets of steel; out came assembled auto frames. This automated system went into operation in 1921 and was in use into the 1950s. A.O. Smith could produce an astounding 10,000 auto frames per day.

“It was incredible,” Tom says. “It was the most sophisticated engineering machine in the world at the time.”

The innovation was driven by need and a desire to dominate the market.

The company started in Milwaukee’s Walker’s Point neighborhood manufacturing parts for baby buggies, evolving to making bike frames and other metal components. (Next time you ride your bike, Tom says, you can thank A.O. Smith’s Milwaukee engineers: they invented the tubular front fork.)

In 1899, A.O. Smith figured how to press the world’s first pressed-steel automobile frame, Tom writes. When Henry Ford himself saw A.O. Smith’s process in 1906, his company ordered 10,000 frames for his Model Ns (prior to the more familiar Model T). A.O. Smith would have to ramp up production. In Milwaukee, they created the world’s first automobile frame assembly line, satisfying Ford’s order in a year. But their success with Ford attracted other interest they could not accommodate. A.O. Smith was forced to turn down orders from other car manufacturers. That motivated the company’s aggressive move to 135 acres along the railroad in Milwaukee’s 30th Street Corridor and the innovation of the Mechanical Marvel. After the first world war, A.O. Smith accelerated auto frame production by several orders of magnitude: 10,000 frames that previously had taken a year to produce now rolled out in a single day. A.O. Smith’s furious productivity allowed them to serve the rising demand, dominate their competitors, and essentially set the stage for the modern car industry.

For decades through the mid-20th century, A.O. Smith was a source of family-supporting jobs. A.O. Smith’s expertise in working sheet steel also contributed greatly to the American war effort in both world wars.

When asbestos-coated weld rods from England became scarce due to World War I, Tom says A.O. Smith invented a new way to weld that used paper pulp and silica salts. This led to their disruptive leadership in electric arc welding—not to mention the company’s production of an incredible 4.5 million bomb casings by the end of World War II.

A.O. Smith’s welding prowess also transformed the oil and gas industry. When German submarines disrupted the global supply chain and threatened to sink American oil tankers, A.O. Smith scaled up their capacity to mass-produce 40-foot segments of huge pipelines by rolling sheet steel and arc welding the seams. American military leaders could now deploy pipelines as an alternative to tankers and safeguard domestic supply of oil and gas. In that sense, the oil and gas pipelines spiderwebbing the globe today like arteries of steel is due to the ingenuity of Milwaukee’s engineers.

“They would see a need and they would morph into various technologies, various different enterprises,” Tom says.

Today A.O. Smith is known as a leading manufacturer of water heaters. How this came to be is a quintessential Milwaukee water story. Wartime copper prices got very expensive, Tom says, but Milwaukee’s major breweries still needed large tanks for brewing our liquid gold. Steel tanks were cheaper but would rust. The solution? A.O. Smith invented a way to coat the interior of the steel tanks with glass. They sold these tanks to breweries and realized the process could be used to make hot water heaters.

Perhaps ironically, the seeds of A.O. Smith’s shedding the auto frame industry that had for decades been its defining line of business came from another Wisconsin auto manufacturer, this one with a one-time plant across town just west of the Milwaukee River: Nash Motors. Tom explains that Nash developed the first unibody vehicle. Ultimately, unibody construction proved both lighter and safer than riveted auto frames because they could be designed to collapse on impact, protecting driver and passengers. A.O. Smith sold its auto frame business to Tower Automotive in 1997, which shut down the corridor plant in 2006.

Tom grew up on 37th Street between Vienna and Nash “in the shadows of A.O. Smith,” which bordered 35th Street. In his early teens, he would bike the neighborhood. Pedaling east of the railroad tracks was to enter a strange and marvelous industrial landscape that must have been magical for a boy his age, filled with factories, storage tanks, large equipment, and bustling with activity. This environment stimulated his natural curiosity for mechanical things.

During World War II, Tom’s mother worked for Evinrude, then located north of Capitol and west of 27th Street (east of Green Tech Station). “Most of the men were in the service, so they backfilled the companies with women,” Tom recalls. “Instead of making outboard motors at Evinrude, they largely moved to other things, like bomb targets and so forth.”

Tom’s dad mainly worked at Miller Brewing, but when periodically laid off he would pick up winter work at A.O. Smith. Tom also has a brother-in-law who worked on the frame line as a welder at A.O. Smith while going through medical school to become a doctor.

Tom attended Jordan High School and later Marquette University where he earned his engineering degree. As a mechanical engineer, he worked for Ford Motor Company in Dearborn, Mich., then moved up the ranks at Wisconsin Electric (now We Energies) back home in Milwaukee, where he married his sweetheart.

As a way to give back to his profession, in 1978 Tom started volunteering as the History and Heritage Chairman of the American Association of Mechanical Engineers, researching and writing a column for the organization’s newsletter. “It kinda gave me an excuse to begin exploring Milwaukee's industrial history. I started focusing on mechanical engineering innovation. The thought being, what are the innovations that really led to the success of all these Milwaukee industries?”

When he retired, Tom had accrued decades of past articles from the history column. This work led to his writing Magnificent Machines of Milwaukee, which assembles the stories of our manufacturing city’s legacy of innovators. Tom published the book’s first edition in 2017. A revised edition was published in 2022.

“[The book] tries to provide a compendium of the significant industrial activity within Milwaukee and the innovations that really led to the success of the Milwaukee industry,” Tom says. He devotes an entire chapter to 30th Street Corridor businesses and features A.O. Smith—as well as other heavy industries that once populated the corridor with family-supporting jobs including Evinrude, Cutler-Hammer, Harley-Davidson, and MasterLock.

Tom’s book provides an impressive overview of local history peeling back the layers of the modern landscape. He highlights the personalities behind machines we take for granted today, reminding the reader that someone first had to invent them to solve some kind of problem. Tom also researched and wrote another book on wartime Milwaukee industry that also features A.O. Smith, When Milwaukee Went to War. These books are handy references and portals for discovering Milwaukee stories hidden in plain sight.

You can purchase Tom’s books on Amazon, through Boswell Books, or Historic Milwaukee, Inc.

They are also available through the public library system:

The Magnificent Machines of Milwaukee and the Engineers Who Created Them

When Milwaukee Went to War