Steve Sass, Heat Transfer & Fluid Dynamics Fellow

Sass takes the heat (literally) for our customers

Portrait of Steve Sass

Imagine having a job defined by uptime, a customer's most valued commodity. A job that if not done properly can diminish efficiency, shut down an operation, and cause equipment failure. A job recognized as both essential and complex.

Now imagine this: The customer could take it or leave it.

Imagine having that job, Steve Sass' job.

"The reality is all of those pieces of equipment that we work with, putting in cooling packages or keeping inverters from overheating, or that fan from shutting down, our customers would be like, 'Boy, if you could make a vehicle without that stuff, that'd be even better.' To them, it's all wasteful stuff," Sass said as he explains computational fluid dynamics (CFD) and heat transfer.

"In their mind it takes away from the actual task of digging dirt or harvesting trees or anything like that."

It's a job Sass never imagined as a child.

After all, he wanted to be a weatherman.

Getting to here

As a principal engineer, Sass' work protects many essential components – from engines to sensors and spans most of John Deere's largest construction and forestry equipment. It also empowers engineers from all corners of the enterprise.

"My job is to do simulation of heat transfer and fluid dynamics to help validate if we're meeting customer requirements when it's still just an idea in the engineer's head. And I'm really trying to help them subdue the earth in the most efficient way possible," Sass said. "I'm trying to get it out there so that this vehicle lasts as long as they need it to last."

In layman's terms, it's delivering on a promise.

"I work to take away ambiguity, and make people feel more comfortable with what we know of that ambiguity," he said.

Sass has proven so proficient in meeting those requirements it's led to him being recognized as an expert and labeled as irreplaceable. In 2021 he received another descriptor -- John Deere Fellow.

It's been quite a journey, landing him at a job that didn't exist nearly 20 years ago. And long before that Sass wouldn't have been interested anyway — he was more fascinated by tornadoes.

The value of learning

A common theme among Fellow Award winners is the push curiosity gives them in understanding how things work. They often wonder how the world around them moves.

Sass is not much different in that regard. He grew up on a farm in the small northeast Iowa town of Elkader. Where Sass' story deviates is in late May 1985 when a tornado tossed barns, toppled trees, sparked power lines, and tragically killed two neighbors.

It was the kind of ambiguity that made sure a 9-year-old never forgot. And then, just three months later, another tornado hit. Both, to a child, were unexplained. Emergencies from seemingly nowhere.

"I kind of noticed this with myself. I'm always afraid of what I don't understand," Sass said. "And I think the thing with the weather for me was if I could understand it, I would have a better idea of when these bad things were going to happen."

That curiosity took him to the library where books taught him about humidity, cloud formations, and temperature changes – a bit of foreshadowing if there ever was one.

"I guess that's kind of been a little bit of a theme throughout my life. When I get into something, I want to dig in real deep and understand it because I'm a little afraid of what I don't know," Sass said. "It started with those tornadoes."

It's that fear – what Sass calls "personal self-doubt" – that has driven him to make sure he has all the information, and answers, he can find when solving a problem.

Getting that information starts with questions and for Sass the ask is as important as the answer.

Why questions matter

With two good examples at home, Sass was set up to tackle most anything. His father preached "lateral thinking" – a way to stretch what you know, and the approach needed to get to a solution. His mother – "a little pocket of dynamite" – taught the value of social connections and mental toughness. They both instilled a work ethic that created a philosophy built on "human effort."

Sass describes his job as "50 percent doing, 50 percent teaching." For him, that teaching portion begins with one basic lesson.

"I have employees come to me and say, 'I want to learn more. I want more challenges.' And my response is, 'Maybe you're not asking deep enough questions on the things you're working on currently. Those opportunities are in front of you. You're just not asking the right questions.'"

The best way to understand Sass' work is to look at the heart of our products – the engine.

First, Sass said, the engine is the main source of energy doing the work to keep itself cool – a vicious circle of irony. It may be asked to pump fluids through an inverter, run belts connected to a fan, or assist in buoyancy (drawing cool air into a space while pushing hot air out).

This is just to keep the engine at an efficient temperature, even if it's being used inside a piece of construction equipment in the desert. Sensors are used to monitor those temperatures. And those sensors have to be kept cool.

"You can see where this can get a little complicated," Sass said. "It's rarely one thing that solves it. The object is to find the right combination of options to make it work."

For Sass, there's one true way to get to the answer.

"We run lots and lots of simulations. A lot of them."

To Sass, simulations are like questions.

"My job is to come up with simulations of those tests that you would use to physically verify it," he said. "And every idea we come up with tests those ideas against those requirements (set by John Deere Power Systems)." Requirements can mean temperature extremes, fuel efficiencies, and horsepower.

Freedom and confidence

Sass said he knows he's been fortunate on his journey with Deere. When he started on CFD and heat transfer he was a department of one and the value of his work was yet unknown.

"I was playing the role of a fortune teller then," he said. "Using all that I knew to give confidence in what I knew and being honest in what I didn't know. I took each failure and pressed it back into the process. But, and this is important, I was never told to do one thing or another. I was given the freedom to explore and figure it out. That's a tremendous gift."

The Fellow Award recognition acknowledges both sides of that – the recipient and the work.

The Fellows honor brings a desire to pay it forward. Sass recognizes his environment allowed him to excel and reach this point and he shares with new hires that vision for work beyond the assigned tasks but work that has passion in it.

The award, he said, also provides hope to others in the company.

"I know for sure there are areas in Deere where you would have said 20 years ago, 'What's that and why does it matter that there are nascent technologies inside this company?' It matters because maybe there is one Grade 6 engineer involved in it that might turn into a Fellows 20 years from now," he said. "You may feel like some of it is the unknown. But if it's your passion, you can make an impact. Ask questions and it won't be unknown for long."

Just like a tornado.

Imagine that.

"What I want to do is make it accessible to the engineers that love the math and love to be able to test out designs, like if they were Orville Wright in the shop trying to make a plane," he said.


Diesel Engine Technology