Back in the late 1940s, Buster Peterson drew up designs for an innovative way to give customers more earthmoving power beyond Caterpillar’s largest tractor of the day, the D8.
Peterson determined that two Cats were better than one and created the “Twin D8” – two Caterpillar D8 tractors joined together for pushing one large dozer blade and running other huge attachments.
As far as anyone knows, none of those original Twins is around today.
Cat lovers, however, need not despair of ever seeing such an awesome sight as the dual D8 creation. Thanks to some antique Caterpillar lovers, the latter generations of Peterson Cat leadership and some really talented technicians, the Twin D8 was recreated in 2013.
Not only that, but that Retro Twin D8, which hadn’t run in about eight years, just finished getting some TLC. It’s now running again – making its return debut at the Great Oregon Steam-Up show and now on display at the Antique Caterpillar Machinery Museum in Salem.
“It's been a really awesome opportunity to be stewards of this historical piece,” says Nate Degerstedt, Peterson Cat technical communicator and trainer, who helped get the twin machine running again. “It's definitely a great privilege.”
(Check out the videos at the end of this story to see the Retro Twin D8 in action.)
The Original Twin D8
Howard Peterson, founder of Peterson Tractor & Equipment Co., with the King Ranch Hi-Clearance Twin, which was delivered in 1951 to the Texas ranch for land clearing.Peterson Cat
Buster was the brother of Howard Peterson, founder of Peterson Tractor & Equipment Co., in San Leandro, California. Buster developed multiple patented innovations for Caterpillar equipment during his time at Peterson, now known as Peterson Cat.
According to the book “Peterson: 85 Years and Going Strong,” Buster’s other recorded Twin D8 was a high-clearance version for the King Ranch that was delivered to Cat dealer Wm. K. Holt Co. of San Antonio, Texas, in March 1951. Weighing 52 tons, it had a 36-inch ground clearance and cost around $55,000. The front had a knockdown bar that could push down trees 40 feet high and 20 inches in diameter. The rear had a Holt root plow that could cut a path 16 feet wide and 16 inches deep to prevent the mowed down mesquite trees from growing back. They also added a seed blower on the rear to reseed as the land was being cleared.
This Cat Twin D8 was delivered to the Hungry Horse Dam project in Montana in 1950. Peterson Cat
Buster obtained a patent for the Twin D8 in 1954. That was the same year, though, that Caterpillar launched its 286-horsepower D9, making the Twins obsolete.
The Retro Twin D8 is Born
The operator station for the Retro Twin D8, based on the Hungry Horse Dam design.Peterson Cat/Nate Degerstedt
In 2012, he met with friend and fellow Cat collector Glen Ghilotti at Akin’s ranch in Placerville, California. Akin showed him a coupling he had specially made for tying the clutches together for a Twin D8.
The pair, along with Duane Doyle Sr., then Peterson Cat president and CEO, came up with a plan to recreate the Twin, based on Buster Peterson’s drawings for one that worked at the Hungry Horse Dam in Montana.
Akin would supply the vintage D8 tractors from his collection. Ghilotti would rebuild the engines and supply the transportation. And Peterson Cat would rebuild the frame and track assemblies and merge the tractors into one. They would use the same bay where the original Twins were built.
The project also coincided with Peterson Cat’s upcoming 80th anniversary in 2016.
“Our goal was to recreate something that was unique to Peterson,” Duane Doyle Sr. said at the time. “And our 80th anniversary was the catalyst for that. There was certainly no financial justification for these machines, but they’re a link to our past. And something we are very proud of.”
Peterson Cat/Nate Degerstedt
Another upgrade was being able to use one lever to drive the whole machine, or each engine could drive its own tracks. They also added an equalizer bar underneath between the two track frames. This allowed the tracks to follow ground contours rather than rocking.
Aside from the few changes, the dozer was built from scratch using Buster Peterson’s original drawings, based on those same principles and appearance. It was equipped with a 16-foot 4-inch blade.
Retro Twin D8 Roars Back to Life
Peterson Cat/Nate Degerstedt
Eventually, it went on static display at Peterson’s branch in Hillsboro, Oregon, where it had been for about eight years when Nate Degerstedt got the idea to spruce it up and get it running again. Caterpillar’s upcoming 100th anniversary in 2025 also made the timing right.
Degerstedt has volunteered for 24 years at the Powerland Heritage Park and Antique Caterpillar Machinery Museum in Salem, Oregon. The park is home to the annual Great Oregon Steam-Up antique tractor show.
“I actually had the opportunity of seeing it run the last time it was at the Great Oregon Steam-Up, and that was close to probably nine years ago,” Degerstedt recalls. “I think for any of us that are Cat enthusiasts, it's a pretty unique machine. It's impressive, what it is and the history behind it.”
About a year ago, Degerstedt spoke with Duane Doyle Jr., current CEO and president of Peterson Cat. Doyle is the great-grandson of Howard Peterson, who founded the company in 1936.
“We got the approval to move forward, and I started working with the management and the crew at the Hillsboro shop location to put in some time and effort to get it up and going again,” Degerstedt says. “I had a lot of great help, guys that are really talented mechanically.”
After an estimated 250 to 300 hours of work collectively, the Peterson crew brought the Retro Twin D8 back to life.
“There wasn't a whole lot of work as far as anything terribly invasive,” he says.
The righthand steering clutch had become stuck. The pony motor had some timing issues. Fluids were changed. Components were examined and addressed as needed. It got a new paint job.
Peterson Cat/Nate Degerstedt
“Shout out and thanks to my counterpart Steve Nelson for pitching in and giving me a hand on this,” he posted along with a photos and video of the Twin in action. “And most importantly, thank you to the owners of Peterson Cat for the opportunity to operate it and and entrusting me to care for this incredible machine.”
Degerstedt admits to being a little nervous about cranking up the Twin.
“For me to have the opportunity to fire it up for the first time – definitely had the jitters,” he says. “It was a little bit of an overwhelming experience.”
But once the engines were running, a sense of relief came.
“We could really kind of sit back and relax and enjoy it,” he says.
Soon after getting the Twin back running, it was on its way down the road to Powerland Heritage Park, where it was on display for the Great Oregon Steam-Up in July and August. The dozer is now at the park’s Antique Caterpillar Machinery Museum.
“People caught wind of the move,” Degerstedt says. “There was quite the crowd of people that showed up to witness it.
“It's really a great opportunity to share, not only Caterpillar’s history with folks, but the Peterson family history in the industry. It feels good, and it's something that I'll always remember.
“Having admired this tractor for a number of years and being able to have a hand in it, as well as the other folks that are working on it, we're all really excited with the opportunity to show it off to the thousands of people that come out to the festival and visit the museum throughout the year.”
Watch the Retro Twin D8 in Action
Degerstedt posted some video of the Retro Twin D8 in action after the Peterson Cat crew in Hillsboro got it up and running again:
Here's some video of the Retro Twin D8 in 2016. It's being operated by Ed Akin and filmed by Glen Ghilotti, both of whom helped make the re-creation a reality. (Both men have since passed away.)
