Clessie Cummins

Clessie Cummins: Hoosier Inventor, from Indiana Public Media, details the life of a Hoosier farm boy with a knack for innovation. The father of the American diesel truck engine, Cummins combined elbow grease, a keen mind, and rural pragmatism to co-found what became Cummins, Inc., a Fortune 500 international diesel and alternative fuel engines company headquartered in Columbus, Indiana.

Cummins Engine Company’s first five years were times of initial optimism, impending doom, dogged determination, and finally, slow climb toward a survival . . . It was a time when Clessie had many failures and disappointments, but the saving fact was that W.G. Irwin and Clessie never weakened at the same time.

• from The Diesel Odyssey of Clessie Cummins, by Lyle Cummins

Like many who encountered the company’s namesake, W.M. Tippett, manager of the farm equipment division at Sears, was turned around by Clessie’s persuasiveness. As another Indianapolis businessman noted after meeting Clessie a few months later, “one couldn’t resist Mr. Cummins’ whole-hearted enthusiasm.”

• from The Engine That Could, by Jeffrey L. Cruikshank and David B. Sicilia

Cummins Chief Technical Officer John Wall would be the first to say that innovation at Cummins began with the genius of Clessie Cummins.

• from Red, Black and Global: The Transformation of Cummins, 1995-2010, by Susan Hanafee

Next to Rudolf Diesel, Cummins may just be the most influential person when it comes to the development of diesel engines . . . Above all, Cummins was a self-made man with a limited education who had a vision and had a goal and worked painstakingly to make it work. It wasn’t easy and at times it wasn’t fun, but Cummins persisted – and the diesel engine as we know it today largely has him to thank for it.

• from dieseltechjobs.com

A good argument can be made that this mechanic-inventor-showman is arguably the most influential figure in Bartholomew County history.

• from “Directory Reveals Clessie Cummins’ Travels,” by Harry McCawley, former Associate Editor of The Republic Newspaper, July 10, 2012

Cummins was brilliant. His products were terrific. Though his products never made it all the way to the family automobile, Clessie Lyle Cummins is undeniably the godfather of diesel power on the American highway.

• Jim Donnelly, Nov 2009, Hemmings website

(At the end of his life,) he knew that much of his good fortune was also a product of being in the right place at the right time. There was no bitterness in his memories of past disappointments which for so long had brought him inner turmoil. It was very evident that he felt a strong familial bond with the Irwin family who had nurtured his talents so they could blossom and flourish … through almost sixty years of good and tense times, the happy ones were most remembered.

• from The Diesel Odyssey of Clessie Cummins, by Lyle Cummins

There was the 1932 trip through Europe with W.G. Irwin in the No. 8 racer, equipped with windshield, fabric top and headlights. There was even the 37-foot sailboat which Clessie spent 4 years off and on building at his farm on Youth Camp road. “The Big Dipper” was completed miles from water in 1944 and then trucked to Madison, sailed down the Mississippi and to Florida. What was it all about? Clessie Cummins explained part of it in the introduction to his autobiography, published last year.

“The history of the diesel engine business in the United States dates from 1911, the year in which the Busch-Sulzer firm began operations in St. Louis, manufacturing the strange European novelty. But several years were to pass before more than a handful of customers could be sold on the engines over here. . . . I undertook a personal campaign, with the crudest of experimental facilities, to reduce this pound-per-horsepower ratio, despite all textbooks to the contrary. These efforts culminated in the invention of the high-speed, light-weight automotive diesel. It was a crusade to provide America’s once-feeble trucking industry with the flexible, dependable, economical power it needed to establish and operate the vast, multi-billion dollar transcontinental highway freight system now serving a nation’s burgeoning requirements. The endeavor I undertook demanded invention, showmanship and faith in an idea. Fortunate, indeed, is the man whose work brings him pleasure far beyond any material rewards. . . . What a privilege, being on hand at the royal birth and throughout the exciting years that followed.”

• Op-Ed from The Republic Newspaper, August 20, 1968

During his youth, willing mentors often showed him how to make things such as his first steam engine, as well as how to succeed in business by selling more newspapers. The oldest of five children, his understanding parents let him explore and learn from his mistakes. A lathe he converted from an old sewing machine at age twelve provided his first real world lessons – use too much gunpowder in your homemade cannon and you will blow out the schoolhouse doors on the Fourth of July – use a boiler that is too thin, heated on the kitchen stove to run your steam engine, and you will scald your mother when it explodes.

Other mentors were drawn to Clessie’s inquiring mind and engaging personality. William G. Irwin, his most influential mentor, hired him in 1910 to be the Irwin family chauffeur. Five years later, with Irwin’s help, Clessie opened a contract machine shop. Four years after that, he became cofounder of an “oil” engine diesel company, in 1919, with “W. G.” as his financial partner. For years afterward, this vital partner would call on Clessie to drive him to business meetings in which Clessie often quietly sat. Later they would discuss what had transpired.

Although his classroom schooling ended after the eighth grade, Dad was an educated man who sought knowledge beyond his own field. On his 72nd birthday, my wife and I gave him a set of encyclopedias (he wasn’t the easiest person to buy gifts for, and his “toys” were beyond our means, but he was an inveterate reader whose interests covered many subjects.). We soon knew that the books were a hit, as a volume would often be spotted on a table by his favorite chair.

With schooling behind him, Clessie apprenticed to become a journeyman machinist, and became a self-educated man with a thirst for knowledge beyond his own field of expertise.

Clessie’s friends spanned the spectrum of society, from industry moguls to uneducated river folk. His warm and ready smile was hard to ignore. From 1935 to 1945, we lived on a 120-acre farm seven miles west of Columbus. Drop-in summer time visitors were always welcomed, whether it was a shop foreman and his family or one of the company VPs, and mother always had ice tea to serve.

His blindness to social status was borne out in 1932, when he and W.G. drove through Europe in a diesel-powered Duesenberg race car to demonstrate his unique fuel system and, hopefully, to license it to a foreign diesel maker. (This is the car he drove that set the first diesel speed record at Daytona in 1931 and months later became the only car in history to go non-stop in the Indianapolis 500.

The nearly 5,000 mile excursion on the Continent and in England exposed him to new worlds – including stays in five-star hotels. Extra days were needed in Paris for Citroen to complete two military vehicles with the first Cummins truck-size engines. During idle moments, Clessie would chat with the Hotel George Cinq doorman, who related stories of World War I life in the trenches. Soon after, Clessie noticed he was being snubbed by the hotel staff. When he asked W.G. about this, he was informed that guests conversing with the help was a social no-no. However, after Andre Citroen himself and his wife arrived in their limousine to show Clessie the sights of Paris, the staff snubbed him no more.

Nor was Clessie easily intimidated. When W.G.‘s grandnephew, J. Irwin Miller, was in San Francisco to be installed as head of the National Council of Churches, he invited Mom and Dad, who lived in nearby Sausalito, to attend the event. Before the induction, they were visiting with Irwin and his wife, Xenia, when Dad pointed out California’s Governor Pat Brown about to pass by their table. Irwin said he would like to meet the Governor, so Dad brought him over. Later, Irwin asked how he knew Governor Brown. Dad’s honest reply was that he’d never met the man before.

The factory and its people were always important to Clessie. He had hired many of these men, and they respected him, knowing he was their equal on a lathe or milling machine. One day, while looking out his office window to the shop across the street, he saw a man loading a strange-looking device onto a truck. Ever curious, he investigated and learned that the truck’s driver was the inventor of a metal testing machine which he called the Magna-Flux.

Clessie was intrigued because an epidemic of broken valve springs was causing expensive warranty costs. He got some new springs from inventory to see if this device could find flaws in them and several were found that would have later failed. Clessie bought the machine on the spot, and learned he was the inventor’s first sale – all of the Detroit manufacturers had turned him down. Cummins later became the first manufacturer to use Magna-Flux and would lead the market in non-destructive metal testing.

His idea for an automotive diesel was born in that same office a few years earlier. On a Saturday morning, two weeks before Christmas 1929, Clessie was desperately wondering how to save the company he had been nurturing for the past ten years. W.G., his ever-patient financial backer, had told him the night before that. in January. its doors were closing. The depression’s onset meant no more orders for auxiliary engines for luxury yachts. Adding nails to the coffin, the company had just fulfilled a profitable government contract to supply generator sets to U.S government remote lighthouses (another Cummins first).

Clessie desperately needed to pull a new “rabbit out of his hat,” as he had on several earlier occasions. This time, though, he came up blank. As luck would have it, serendipity struck with perfect timing. While scanning a trade journal, he came across an article about an American diesel “guru” who had not only omitted his engine company in the list of diesel engine builders, but had said the diesel would never be successful on the road. This was the challenge that Clessie was only too eager to accept.

Three weeks later, Clessie and his chief engineer, H. L. Knudsen, left Indianapolis in a used 1925 Packard limousine, powered by a Cummins marine diesel, for New York City and the 1930 Automobile Show. Clessie had even dared to give a reporter the date and time of arrival. Against all odds and in miserable winter weather over rutted, frozen roads and detours, he not only arrived at the announced time, he also had completed the trip for a fuel cost of only $1.38. This depression-era feat was to open a new and secure future for the company.

All went well for a few miles going downstream when it, too, seized. The boat drifted to a river bank and Clessie searched for something in his “junk box” to attempt an emergency repair. In it, he found a piece of heavy copper wire which he pounded solidly into the space where the failed bearing had been. The engine started, and they went back upstream past Madison to see if the temporary fix would last. It did, and a new, suitable bronze bearing was quickly adopted and used until his next generation pump went into production.

Another river trip brought unexpected publicity. W. G. had invited Indianapolis and Chicago newspaper reporters to see a new engine model installed on the test boat. Clessie was not informed of this until W.G. suddenly called him to drive them the forty miles to Madison for the demonstration. When Clessie told W.G. they would need to add fuel for the boat first, his retort was that these people had no time to waste while five gallon fuel cans were toted down the bank to the boat.

W.G. insisted on going down river because the financial partner considered it more scenic. The inevitable soon happened, and the boat was drifting without power toward Louisville. Embarrassed, Clessie recalled how he once had gotten out of a similar situation: the fuel line suction pipe extending into the boat’s flat tank stopped a little way above its bottom, and as fuel is lighter than water, he could add water in the tank a little at a time to raise the remaining fuel up to where, maybe, they might be able to limp home.

He jokingly told the guests watching him pour a few buckets of river water into the tank that he hated to do this to a good engine, but it was necessary. Sure enough, Clessie’s quick-thinking solution worked and, after one more stop to add water, they made it back to Madison. The next day, several papers reported that Clessie had made his engine run on river water, a seemingly magical feat that especially amused his industry friends.

The years of physically punishing his body took its toll, beginning in 1938. During the war, he was mostly in Washington, D.C at War Production Board for eighteen months, as head of U.S. diesel engine scheduling, but the job entailed tiring train trips around the country. By war’s end, he felt it necessary to take early retirement at age 57.

Although now living in the San Francisco Bay area, he would remain company president for two more years, after which he was made Board Chairman. In this time period, he received a patent for a new fuel system that went into production a few years later. Repowering yachts and rebuilding foreign cars were aided by his machining of needed parts he would make in a machine shop set up in his home garage wherever he lived.

Adversity often fueled his creativity (and where I became one part of his story). With my graduate mechanical engineering degree, Dad said he wanted me to help with an idea he had for an engine brake. This was the last thing I wanted to do at the time, but Dad could be very persuasive!

What had stirred his passion to do all this at the comfortable age of 68? Well, twenty five years before, Dad nearly lost his life driving a runaway truck down the Cajon Pass into San Bernardino during his 1930 coast-to-coast speed run. He vowed at the time that he would find a way to convert a diesel into an effective vehicle retarder, but the intervening years of more pressing business matters had always postponed fulfilling that vow.

By 1955, when he still had the time and energy to attack the problem, I came to understand more of what made this man tick. During the next seven years, l witnessed a man who saw what others dismissed and prove them wrong. That idea grew from a sketch into a product which would create a new industry.

He set up an enviable machine shop filling two of the five stalls in his basement garage, hired a very capable machinist, and let me cut my teeth on designing an engine brake. Neither of us were happy with the original solution I was carrying out. Then he called me one morning and said, “Hold everything, I’ve got it!” To prove this new concept was workable, he bought a 1956 GMC Suburban and repowered it with a smaller six-cylinder Cummins diesel by lengthening everything ahead of the firewall about twelve inches.

This crude prototype worked – and scared a few invited passengers when the engine brake was applied on Sausalito’s steepest streets. Prototypes for Class 8 truck highway diesels were then tested on one engine in Clessie’s 96 ft. yacht docked in Sausalito. The front four cylinders simulated a truck going downhill, and the rear two cylinders acted as the retarder.

While prototypes were being tested, and with a patent pending, Clessie contacted U.S. truck diesel builders to buy a license but was politely rejected by all. Instead, a drill chuck maker in search of a new product heard about the brake through a friend of Deloss, Clessie’s brother. Impressed by mountain highway demonstrations, The Jacobs Manufacturing Company bought a license in 1959. Because they were entering a new field, Jacobs was guided by Deloss and his son Don both before and after the new engine brake was introduced in 1961 as an aftermarket, and within a few years the diesel builders who had turned down the idea were now buying it for factory installations – he had created yet another industry.

In many ways, it was a replay of his earlier years, but this time I was able to sit in meetings while Dad promoted his ideas, negotiated contracts, and argued at the Patent Office, and I could observe his belief in what was ethical and moral clearly. His “right” and “wrong” switch had only those two positions and he never lost a night’s sleep over stress created by gray areas his God-fearing parents had taught him to avoid.

Once, a question arose about Dad claiming a tax write-off for use of his yacht for a test lab, and his CPA was having difficulties convincing the IRS examiner about it. Finally, Dad said, “Bring the man over and we’ll show him what we’re doing.” His CPA didn’t like the idea, but gave in. On the day of the visit, I had the engine running and the brake operating. After it was all over, the examiner told Dad, “You’re absolutely justified, and, I envy you.”

Dad was 75 when I left to work for Jacobs in Connecticut (1), but close ties remained while there and in other eastern states as we had also developed and patented a new fuel system licensed by two manufacturers.

Yet he still had an idea to build an engine with a unique barrel configuration, a concept that he had dreamed about for years So he hired a good designer, and with Clessie machining many of the parts for it, plus helping with its assembly, he started up his dream engine in December 1967. It powered a water dynamometer in another of his garage stalls, and gas from the line supplying the house furnace was piped to the engine. The exhaust was spliced into a downspout from the flat garage roof.

Within weeks of this momentous occasion, my Mother, a true helpmate, was to die from a long ordeal with cancer. Six months later, after working on the engine one evening, Clessie joined her. At 79 years, he had enjoyed a long and productive life.

(1) Cummins Inc. acquired Jacbos in 2022

• See more images of Clessie at the Cummins Company History web page
• See more images of Clessie at the Automotive Hall of Fame