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technology & culture

royalties for Rolling Steel

crowning the King

The year 1938 was selected for the 15th anniversary of the continuous mill. It was celebrated in Ashland Kentucky with about 40,000 people from Ohio, Kentucky and West Virginia. John Tytus was crowned the king of rolling steel in horse racing style.

15th Anniversary of Continuous Mill, October 19, 1938 Ashland Ky.
15th Anniversary of Continuous Mill, October 19, 1938 Ashland Ky.

The leadership of America’s steel industry were present.  Happy Chandler, then the governor of Kentucky and later the commissioner of major league baseball led the celebration, applauding Tytus as the “unsung hero of the streamlined age.” Crout & Voris, pg. 145

The continuous mill was one of many innovations for the American Rolling Mill Company including Armco Ingot Iron, the 99.87% pure iron that resisted rust, Hel-Cor galvanized pipe for road culverts and the development and production of electrical steel. The company played a significant role in the establishment of the steel prefabricated housing in the years before World War II.

The American Rolling Mill Company employed not just steel makers but a public relations department that produced documentation praising the their accomplishments:

Armco 1901-1927 Twenty-six Years of Progress

The continuous mill got its own treatment here:

Latest Contribution to the Iron & Steel World

Tytus was not just the focus of the accomplishment, as Vice President of Rolling he was also the gatekeeper of new ideas for rolling steel at Armco. The second greatest test of Tytus’ career as a sheet steel innovator came just after the Ashland celebration in 1938.


Armco draws an Artist

Arrangements were underway to bring a Polish inventor named Tadeusz Sendzimir to Middletown. Sendzimir was a galvanizing expert; the Sendzimir Process coated flat rolled steel with a layer of zinc with quality unmatched by the technology of the day.

380 × 450 face

But by the time Armco approached him in the mid-1930s, the inventor had moved on to other ideas and was neck deep in a different steel processing enterprise in Europe: he was designing, selling and supporting early versions of a new kind of rolling mill. This new, a single stand configuration with a similar configuration as the manual mill but capable of rolling steel sheet very thin with an extremely flat cross-sectional profile. It was a capable mill – when it worked – but Tad Sendzimir was a one man operation and played all three roles as artist, artisan and artificer.


“Artist, artisan and artificer are here compared as they mean one associated with art. The work of an artist is creative; that of an artisan, mechanical. The artificer is between the two, having less scope for the embodiment of his own ideas than the artist, but more than the artisan, who usually has none.”

Standard College Dictionary, Funk and Wagnalls, 1966


It was a slow start; his early mills were promising but not perfect. Eventually Sendzimir would be known as he is today, the artist as engineer who built the Sendzimir Mill (or Z-mill as it’s often called), not for the superb galvanizing process he invented as a young man that initially brought him to Middletown Ohio.


Sendzimir’s streets

Today John Tytus and his continuous mill remain relatively unknown among many of Middletown’s current inhabitants. The memory and accomplishments of Tad Sendzimir are even more remote. The only remnants are street names. Tytus Avenue in Middletown acknowledges the paper company not the man credited with Armco’s continuous mill.

Tad Sendzimir also did well in the short time he lived in Middletown and developed a small piece of property in Madison Township across the Miami River from downtown.

At the crest of Hill Street, Sendzimir platted three narrow lanes and built a small Steelox house along Emerson Road, named for Earl Emerson. Mr. Emerson was the vice president of Armco International and helped smooth the way for the Polish engineer’s immigration to Middletown. Further up the hill are two streets dedicated to the towns in England that took a risk on his rolling mill during the troublesome early days: Sheffield and Shotton Roads.


Sendzimir called his development Cascade Lakes. He intended to add another pond to validate the plural name of his hideaway but after the war, circumstances led him away from Middletown. The story of John Tytus and innovation at Armco continues with Tad Sendzimir and his effort to get his mill built. Sendzimir’s experiences in Middletown reveal a mid-20th century trial of a lone inventor pursuing his vision in a modern American corporation.


Not Invented Here


Frans Johansson elaborates on how established expertise can be a barrier to innovation,

“…expertise, for all its strengths can make it more difficult to break out of established patterns of thought.”

pg. 52


In other words, success can be a trap.

Tytus was firmly in charge of rolling at Armco as Sendzimir arrived. According to a book written by Tad’s daughter Vanda, Tytus  met his rolling mill idea with skepticism and indifference. It was on Tytus’ authority that Armco leadership followed the opinion that the Sendzimir Mill was a toy. All were convinced except a guy who knew better, Dr. Anson Hayes, Director of Armco Research.


“Good ideas fall on barren soil. John Tytus fought and won his case against Tad’s rolling mill in part because of ‘NIH’ [Not Invented Here].”

Vanda Sendzimir, pg. 163


Sendzimir began his work in Middletown within a small office in the Armco Research building that still stands as the last remnant of steel making on Curtis Street. Dr. Hayes was Sendzimir’s direct supervisor and both shared a mutual admiration for each others work.

As was the case with Tytus and the continuous mill, corporations of the day assigned their patents carefully. Sendzimir was very aware of this and arranged a unique business relationship leading to dual roles: he was an Armco Research employee and a vice-president of a joint venture with Armco. Sendzimir controlled 51% of Armzen, the partnership created to develop his rolling mill with Armco. A rolling mill that didn’t get much respect next door at the General Office along Curtis Street.


the Rad Lab comes calling

At about the same time that Tad Sendzimir was making his transition to life in southwest Ohio, the Wall Street millionaire Alfred Loomis was financing a laboratory at the Massachusetts Institute of Technology called the Radiation Laboratory or Rad Lab. Loomis’ investment was designed to refine radar developments occurring in Britain for war production.

A L Loomis
Alfred Lee Loomis
Wall Street financier
and amateur scientist

Electrical engineers and scientists at the University of Birmingham in the UK improved a German invention for generating microwave energy called a multi-cavity resonant magnetron.   While crude by modern standards, their systems could spot Nazi bombers up to 150 miles from the English coast, enough of a warning for Royal Air Force fighters to intercept them. But the radar apparatus was too bulky to mount on planes, and the equipment was not sensitive enough to detect the periscopes of German U-boats.

The first multi-cavity magnetron developed for radar was patented in Germany in 1935. It required a lot of power and its unstable output convinced the German high command to shift to the klystron. At the time, the klystron output had better target resolution than the  magnetron but with much less range because of power limitations. Magnetrons would eventually get the power they needed from a pulse transformer built with electrical steel developed at Armco and rolled on a new kind of mill.


The scientists at MIT’s Rad Lab had to find a supply of electrical steel with very demanding physical properties. The nation’s supplier for electrical power systems driven with alternating current was a company in Pittsburgh called Westinghouse Electric Company. Westinghouse got its electrical steel, or silicon steel, from the company that perfected its manufacture – the American Rolling Mill Company.


MIT first approached Westinghouse, who directed them to Armco, who in turn directed them to Tad. As Tad sat in his office in Middletown one morning, a gentleman from the MIT Rad Lab walked in, introduced himself, and explained that his project needed very, very thin silicon steel – 0.002 inch. So far, everyone told him the mill didn’t exist that could roll such steel. Tad’s eyes fairly drilled through the fellow. “I can make strip that’s 0.002 inch thick,” he told him. “If you want, I’ll even make it 0.001 inch.”

Sendzimir, pg. 167


At the time, only one Sendzimir Mill had been built in the US. The Signode Corporation of Chicago purchased one of Tad’s mills to produce, ironically, the steel banding necessary to prevent steel coils from uncoiling. The mill was never intended to roll hard steel, just the soft stuff. A young engineer from Armco Research named Charlie Smith took a ton of electrical steel to Chicago to see if he could roll it down to the specifications MIT was demanding. The mill broke many times during countless trials but the Armco team finally pulled it off and presented the finished product to the engineers and scientists at MIT.

And Signode slowly began rolling out this fine, thin steel. The steel was used in the transformers, which put radar on the planes fighting the war. (Signode later earned a special medal from the War Department, but the mill’s inventor was never so recognized.)

Sendzimir, pg. 168


Charlie Hook decides the battle to fight a War

Electrical steel rolled to 0.002 inch thick became a strategic material. Having a single, small rolling mill retro-fitted from producing steel banding was insufficient for both Westinghouse and the War Department’s Production Board. Armco leadership was feeling the pressure to build more capacity for the fundamental component to radar pulse transformers but were still reluctant to further develop, let alone promote, the Sendzimir rolling mill.

Calvin Verity was against it.

Westinghouse put it this way: “Either you build a Sendzimir mill, or we’ll build one and produce the sheets ourselves.”

John Tytus, the story goes, balked: “As long as I’m in charge of the Armco rolling operation, there will be no Sendzimir mill in Armco plants.”

Doc Hayes phrased it another way: “Put a Z-mill in or find another Director of Research.”

Gurney Cole, an Armco manager and one of Tad’s champions, kept pushing. John Tytus said to him: “Gurney, you’re a nice man, but you’re making an absolute fool of yourself over the Sendzimir mill.”

Finally, Charlie Hook, Armco’s president, stepped in to overrule Tytus’ men – who thought the Z-mill was a toy.

Sendzimir, pg. 169


Sendzimir mills continue to be built today but not in Middletown Ohio. After the war, Tadeusz Sendzimir moved his engineering firm to Waterbury Connecticut where it still operates designing and installing Z-mills in several countries.

The story behind his move to New England from Ohio reveals how the social dynamics of a small, middle American town impacts economic development. The community’s reaction to the lone inventor was described in his daughter’s book as a place too provincial and parochial to pursue his work. Armco wasn’t providing an economic incentive to stay in the area and the community was perceived as culturally myopic with a narrow range of interests.

Throughout the war years, Middletown and surrounding areas provided the talent Sendzimir needed to refine his mill and engineer it for production. Armco Research was a place where ideas for new products and processes were put into production on a regular basis. There were plenty of accomplished artificers and artisans for the artist to lead.