CASE STUDY Industrial

Series 60 repower boosts productivity for one of the largest yarder towers in the world.

Posted on March 26, 2018

Logging in the dense forests of Washington’s Olympic Peninsula is challenging work. Steep mountainous terrain and twisting gravel roads make a logging truck’s daily commute long and treacherous. It rains more than 200 days of the year, dumping 10 to 12 feet of rainfall. Brisk winds from the nearby Pacific Coast add another degree of difficulty. Despite all these obstacles, Dahlgren Logging Inc. has harvested timber here in the mountains and canyons for nearly 60 years.


Dahlgren Logging Inc.


Series 60


24/7 reliability, power and low maintenance


Forks, Washington, United States

The yarder tower is our most important piece of equipment. Now, it’s bringing the wood up the hill much faster.

Pete Dahlgren - Dahlgren Logging Inc.
Headquartered in the small town of Forks, Washington, Dahlgren Logging was founded in the early 1960s by Joel and Ingrid Dahlgren. Today, four generations of Dahlgrens keep the company humming. Pete Dahlgren runs the company now, with family members involved every step of the way, from the logging site to the office. The operation runs like clockwork, cutting and hauling 17,000 truckloads of logs each year from private landowners. And at 87 years old, Joel can still be found outdoors putting in a full day’s work.
When early settlers harvested timber near Forks nearly 100 years ago, they used teams of oxen. Nowadays, logging equipment with powerful engines do the heavy lifting. Dahlgren Logging has a full arsenal of equipment at its disposal. “We can tackle just about any job. We’ve got a crew of 40, along with logging trucks, loaders, bulldozers and eight yarder towers. We’re actually one of the few tower loggers left,” says Pete Dahlgren

High-wire performance

Yarder towers are mobile tree hauling machines equipped with a telescoping tower that extends high above the forest floor. A sky line consisting of thick cables runs between the tower and a huge stump further down the hill, where the logs are cut. The machine fires up its hoist, pulling heavy logs through the air on the sky line, like a chairlift moves skiers up a mountain. Then, the logs are deposited at a landing area and loaded onto trucks. Capable of hauling a 150-foot, five-ton tree from more than 5,000 feet away, the Berger-manufactured Yarder Tower is a true force in the forest, making logging and timber transportation easier for Dahlgren Logging Inc.
Weighing in at 160,000 lbs. and towering 110 feet above the forest floor, Dahlgren’s Berger M2R Yarder Tower is the second largest yarder tower in the world. This heavy-duty machine is equipped with a backup camera system, a 48,000 lb. tower that extends from 78 feet to 110 feet high and a main cable drum that houses 5,000 feet of 1 3/8-inch diameter cable. The tower is key for Dahlgren’s operation, and when it came time for a repower, a Detroit Diesel Series 60 engine from mtu distributor Pacific Power Group was the top choice.

Qualified for the job

“We’ve got 13 logging loaders that run on the Series 60—and most of them are factory remanufactured. We’ve been pleased with their performance. So we decided to switch to the Series 60 for our yarder tower,” says Pete Dahlgren.
Hauling heavy trees from the forest requires an engine that can handle heavy stress and long operational hours, making Series 60 engines from Pacific Power Group perfect for the job. The engine’s reliable performance and superior construction make them well suited to challenging conditions. The 630 HP Series 60 remanufactured engine selected for this yarder tower provides the performance, smooth operation, low maintenance and extreme power and torque that’s required for logging the tough terrain around Forks.

Off to a flying start

The repowered yarder tower has been hard at work in the forest since January 2017. Recently Joe Grycko from Pacific Power put it through its paces and analyzed its engine data. “This is quite a step up. When the yarder throttles up to fourth gear, running 1800-2000 rpms, those logs are flying up the hill at 60 mph on those cables. The cable drum spins like crazy,” says Joe. “The original transmission was 3-speed only. Now, they have a 6-speed transmission and much more horsepower, which equates into faster line speed and more production.”
And for a logging company, productivity is everything. “Logging is not a straight line. We go up a hill, then down a hill. When there’s a slowdown in any part of that process, you’re not making any money,” says Pete Dahlgren. “The yarder tower is our most important piece of equipment. Now, it’s bringing the wood up the hill much faster. Our landing site gets buried in logs, and we can barely get enough trucks up there to carry them away. It’s doing what it needs to do, and doing it well.”