Pärhä Oy: “Lokotrack® powerhouse – Efficient electric crushing and screening”

“The Lokotrack® secondary crusher is a true powerhouse. Its robust diesel engine drives a generator that supplies power to the unit’s own equipment: the pre-screen, the cone crusher, and a large two-deck screen. Thanks to a connecting cable, surplus power also runs a separate large three-deck screen for final product separation,” says Jari Pärhä, entrepreneur of the family business Pärhä Oy. 

Jari Pärhä is more than satisfied with the cost-efficiency of Metso’s two-stage plant and mobile screen. The primary crushing is handled by the diesel-electric Lokotrack® LT120E™ jaw crusher, followed by the electrically powered LT330GPSE™ cone crusher-screen unit, and precise final classification is done by the e-Power Lokotrack® ST4.10E™ three-deck screen. 

“We calculated that all Metso crushing and screening units powered by diesel-generated electricity, plus two-wheel loaders on site, consume about 0.7 liters of fuel per produced ton of aggregate – which is quite a modest figure,” Pärhä says. 

Continuous development 

Pärhä Oy’s partnership with Lokotrack began in 2013 with the purchase of an LT106 jaw crusher. Four years later, capacity was increased with the diesel-electric LT120E jaw crusher and LT330GPSE cone-screen plant. Last year, the primary unit was upgraded to a new model based on excellent performance.

Automation has also advanced significantly, making operators’ work easier. Additional features such as Remote IC remote control improve equipment management and enhance safety. 

Pärhä applies a method familiar from Norway and Sweden, where the LT120E jaw crusher operates separately, about 20 meters away from the secondary crushing and screening units. A wheel loader picks up the primary crushed rock and feeds it into the LT330GPSE via a feed hopper. 

The secondary crusher differs from mainstream setups: material passes through a pre-screen before entering the cone crusher, allowing fines and selected fractions to be removed when needed. 

“For concrete aggregates, quality is more important than quantity. With the feed hopper and pre-screen combination, we ensure a steady, continuous feed to the secondary crusher, which stays consistently full. This improves cubicity and extends the wear life of parts,” Pärhä explains. 

“The LT120E is also powerful enough that in separate operation, we don’t need to run it at full capacity all day,” he adds. 

Concrete aggregate expertise 

Based in Heinämaa, Orimattila, Pärhä Oy is recognized as a specialist in concrete aggregates. The family-owned company operates six quarries in the Päijät-Häme region, producing mainly crushed aggregates for concrete plants. 

In March, Metso’s two-stage plant and mobile screen were completing a 35,000-ton contract at the Pennala quarry south of Lahti. In addition to 6–12 mm and 12–16 mm aggregate sizes, the process produces stone dust and 3–6 mm grit for winter sanding. 

The reddish rock is crushed in two shifts, including necessary maintenance work. 

“We produce about 3,000 tons of smaller concrete aggregates per day. For larger sizes, the output would be even higher. Finished aggregates are delivered within a radius of about 100 kilometers,” Pärhä says. 

Looking ahead 

What will Lokotrack and other quarry equipment look like in 40 years? 

“Rocks will still be reduced in jaw and cone crushers. Automation will make work even easier, lowering the threshold for new people to join the industry. Remote operation will become more common, and quarry equipment will be controlled more from monitoring rooms than from machine cabins,” Pärhä predicts.