Quadtrac Development

A New Machine

One of the key innovations by Case IH in the 1990s was the Quadtrac. The high floatation provided by tracks is of great interest to farmers, as it allows them to get in the field when conditions are too wet for tires and also compacts the soil less, which is better for the crops.

When Quadtrac project engineer Brian Vick came to North Dakota to be part of the Steiger engineering team headquartered in Fargo, the Quadtrac program was just getting going. The engineering team felt a track system could work very well with the Steiger chassis. They also had some unique ideas on how to make the track system more effective than other tracked tractors on the market.

“The Steiger team is made up of very hands-on engineering-type of people, and most of them have a farm background. We were just excited by the concept,” Vick said. “Some of the old Steiger guys immediately saw the value of putting tracks onto a Steiger frame.”

The most competitive tracked vehicle on the market in the 1990s was the Caterpillar Challenger, which used two large tracks. The concept for Quadtrac was to use four tracks, which would be more maneuverable than the Challenger, and avoid the problems created by skid steering. The team also wanted all four tracks to be able to pivot, which would improve traction as well. The Quadtrac would also have the advantage of a Steiger chassis, which can both articulate and oscillate. This means it can bend and twist in the middle, which is another advantage in rough ground. The engineering team concept was to create a tractor that keep the tracks on the ground in almost any terrain, giving class-leading traction and minimal compaction.

The engineering team had been doing concept work on the Quadtrac in the late 1980s, and had figured out that the major challenge was that the tracks and undercarriage used for dozers and excavators couldn’t handle the 20 mile-per-hour transport speeds necessary for farming. In 1989, Case IH turned to Goodyear to develop tracks, which were embedded with cables that would hold the track together even when driving at transport speeds. That worked out well, and the Case IH-Goodyear partnership was a long-lasting one that continued for decades.

The Quadtrac prototype was shown at the 1992 and 1993 Farm Progress Show. This photo is from the 1993 show. Brian Vick Collection

Once a prototype was built, enthusiasm for the project began to build, particularly within the ranks of those who worked with the early machine. “When you just look at some of the early concept pictures, it was very nontraditional and there was a lot of skepticism,” Vick said. “After you drive the prototype, then you’re sold.”

The engineering team brought management members through the plant to see (and drive) the machines, and slowly convinced them that this concept was viable.

The project took another step in the early 1990s, when Quadtrac prototypes appeared at the 1993 and 1994 Farm Progress Shows. “There was just tremendous customer enthusiasm for the prototypes at the shows,” Vick sad. “Guys were saying they could get into the field earlier and would be able to work in the marginal conditions. Even when they know they shouldn’t be there, they can get their job done and get a crop in a marginal season. That just had tremendous value for them.”

“It’s probably that customer enthusiasm that really drove us after ’94 to get it launched for production.”

While the Goodyear tracks worked well, the undercarriage was another matter. Steiger initially outsourced the manufacturing of the undercarriage to companies with experience with excavators and dozers. The results didn’t work for agricultural vehicles, and the team determined they would need to build their own.

That wasn’t an issue, as the team in Fargo’s forte is heavy steel manufacturing. The tricky part was understanding that the design requirements were more complex and all-encompassing than just building an undercarriage.


Another view of the prototype Quadtrac. Brian Vick Collection

“We had to actually go through and redesign the entire architecture of the tractor to build this from the ground up to be a track vehicle,” Vick said. His team trying building undercarriage components that simply bolted up, with unsatisfactory results.

“The structural loads that go through a tractor are very different between a track vehicle and a tractor on tires. So we had to actually change the chassis and the axles to really make this a solid track vehicle.”

The chassis had to react properly to the forces exerted by those tracks, and the team had to design a chassis and axles strong enough to handle tracks. Steiger ended up changing the specs for all the tractors so that any Steiger machine could handle tracks.

Another challenge was the seals for the undercarriage wheels, which are put under extremely high loads. They have to spin quickly, and work in extremely gritty conditions. The solution was for the Steiger team to design a new seal (which they patented).

The suspension system for the track undercarriages required significant design work, as did the isolation of the cab. Rubber isolators and linkages had to be carefully engineered to protect the chassis and the operator from the forces generated as the tracks crossed the ground.

The result of all the engineering is a machine that has terrific traction in any terrain. As envisioned, the system has four tracks that pivot on a chassis that can twist and bend. Quadtracs can handle the worst field conditions with aplomb. The system is also uncommonly smooth. “The main thing is you’re just bridging over all of the sharp jolts in the field, all the ridges and furrows. So you glide over the sharp contours of the field,” Vick said. “It’s very, very smooth in the field. We do have some of the older customers, some of the older gentlemen, who’ve told us they were planning to retire, and after they got the Quadtrac tractor they decided to stay in the business for a few more years because the ride is so much better.”
 

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