April 2003 - Logging and Sawmilling Journal -

Advances in site prep tools by Swedish company Robur Maskin—and solid partnerships with its distributors in Canada—are resulting in benefits to both contractors and forest companies.

While the term optimizing is usually applied to high-tech computer sawmill equipment that delivers greater efficiencies, optimizing is also being done out in the bush these days. Scarification tools are evolving towards becoming highly responsive computerized devices so that site prep contractors can operate more efficiently with less downtime, while at the same time still giving forest companies the high results they require.

Advances in planting and seeding practices have also played an important role over the past decade. Combined with the development of new tools, contractors working in the challenging Canadian climate are now able to deliver superior seedling survival and growth rates—in variable terrain and soil conditions—to their forestry clients. Swedish company Robur Maskin, a world leader in the manufacture and distribution of site prep equipment, has introduced a number of improvements to its product line to help contractors meet the challenges of today’s demanding site prep environment.

“We have said that first we have to sell the method to the landowner and then the machine to the contractor,” says Klas-Hakan Ljungberg, president of Robur Maskin AB. The business was founded by Ljungberg’s grandfather in 1922 and sold to a company called Contrafact AB in 1983. Since then, it has grown by acquiring both the Donaren and TTS lines of site prep equipment to add to its own Bracke brand products. At the same time, it has continued to make significant improvements to its disc trencher and mounder, also known as a patch scarifier. In the mid-1990s, it introduced a new product—a one-pass mounded site preparation and mechanical planter system.

Ljungberg says the acquisition of Donaren and TTS has resulted in the best ideas from all three product brands being combined into Robur Maskin’s current product line. The most significant advances have been the use of heavier steel, a heavier duty planetary gear on its disc trencher resulting in significantly extended service life, less electrical wiring and exposure to the elements, and standard digital computer hardware—with powerful software capabilities— being incorporated on all three equipment types.

For example, there were 40 wires leading from the company’s old computer control system compared with only three from its new one. Robur Maskin has managed to keep its control system operator-friendly. The average operator can learn the computer’s capabilities in about a day. The company has solid distribution partners in Canada. Recently, Hakmet became Robur Maskin’s distributor in Canada from Quebec east, as a result of Robur’s acquisition of TTS. KBM Forestry Consultants Inc in Thunder Bay, Ontario has handled Robur Maskin’s site prep equipment line since 1975. They own the distributorship from Ontario west. “KBM has a lot of site prep and forestry knowledge,” says Ljungberg. “They have been a good distributor for us.” Like Robur Maskin, which began by manufacturing scarification equipment before becoming part of a larger full-service silviculture planning, implementation and equipment supply company, KBM Forestry Consultants began as a site prep contractor and equipment supplier in 1973.

Today, it is a fully-integrated forestry services company involving equipment sales and service, as well as forest management, silviculture and environmental management consulting services. It also participates in research and development projects with northwestern Ontario educational institutions. One example of the company’s integration involved KBM’s consulting division adapting Truckbase GPS mapping technology for site preparation tools. This included testing of these tools by the contracting division and distribution of the system to clients in central Canada by the sales division.

The company has even expanded operations to Chile. KBM Forestry Consultants continues to offer contract site prep services, treating on average 10,000 hectares annually in northwestern Ontario. KBM’s sales manager, Jim Pare, says Robur Maskin has been very responsive to the requirements of Canadian contractors. “They listen to us with regard to what we need here in Canada,” says Pare. “It can sometimes be different than what they need in Sweden. We’ve worked together to develop new ideas of doing things.” He views Robur Maskin’s acquisition of other equipment suppliers as a positive move because it has led to a more streamlined product line.

It has also resulted in some fairly significant product developments. “The improvements they’ve made give the operator a lot more flexibility when they are in the block and doing site prep work,” says Pare. “For example, one area might have lowlands and the remaining area uplands. How you do site prep in those two areas is quite different. The fact that the equipment is computer-controlled allows the operator to apply a different treatment in different parts of the cutblock from a control panel in the cab while the machine is operating.”

The result, he says, is more and better planting sites, leading to faster growing trees and more wood per hectare down the road. The purpose of site preparation is to create microsites to replant or reseed a harvested area. Site prep equipment such as disc trenchers and mounders are pulled along or mounted on either a forwarder or skidder with the objective of removing the top insulating layer of organic material and building a soil berm or mound to allow the sun to heat the soil. Organic material is incorporated into the mound, providing critical nutrients and moisture for the seedling to establish a healthy root system, while discouraging growth of competing vegetation and insects.

“The humus creates a compost effect,” says Ljungberg. “The increase in soil temperature from 10 to 15 degrees in the boreal forest allows you to gain a lot in growth.” The Robur Maskin line, suitable for work in both North America and Scandinavia, continues to evolve. One of the most important research and development partnerships the company has developed over the years has been with the forestry division of Swedish multinational, SCA. The company has been involved in site prep since 1967 and on average treats about 16,000 hectares per year.

SCA has worked hard to develop a highly efficient and productive silviculture program because it is the largest private owner of forest land in Europe—a total of 2.6 million hectares, of which two million is productive. With its seven sawmills, three paper mills and a pulp plant in Sweden, it has a strong economic incentive for optimizing the benefits from its silviculture program. SCA director of silviculture field contacts, Mats-Ake Lantz, has been responsible for implementing silvicultural programs aimed at maximizing seedling survival rates and growth for the first 25 years.

In the late 1990s, the company conducted a four-year study to establish standard equipment specifications for scarification and many of its findings have been incorporated into Robur Maskin’s equipment designs. KBM Forestry Consultants has struck a similar relationship in Canada with Abitibi-Consolidated to develop simultaneous seeding and site preparations systems for their freehold lands near Thunder Bay. The research from this relationship led to pneumatic seeding systems that have successfully reforested more than 30,000 hectares at considerably lower costs, compared to planting.

The SCA study established criteria for selecting either the three or four tooth mattock wheel mounder. Its findings also helped to establish the features now available on Robur Maskin’s new computer control system for both its mounder and disc trencher. It is a digital system built by German manufacturer IFM. The control system consists of eight pre-set options—six for trenching and two for mounding. Essentially, it allows the contractor to input site-specific scarification instructions, as well as temporary pre-programmed settings. With the push of a button, the scarifier is then able to make a temporary adjustment so that proper site preparation technique is used on specific ground conditions.

Disc trenchers are used in about 40 per cent of SCA’s current scarification program—particularly in areas with a lot of big stumps and rocks—but the company prefers to use a mounder. “If we can use the mounder, we use it everywhere,” says Lantz. Over the years, SCA has witnessed better seedling response in mounder-created microsites, particularly in the first five years. However, mounder use has not been entirely responsible for the improved seedling response. In addition to better microsite development and proper placement of seedlings, Lantz says the company has also benefited from better quality nursery stock. SCA also makes use of Robur Maskin’s Bracke planter for difficult sites with limited access to high water tables. It can plant approximately 300 trees per hour, mounted on a wide-tracked excavator or harvester.

Research, re-engineering leads to advances in site prep equipment

By Tony Kryzanowski

Robur Maskin's scarification tools can be mounted on a variety of prime movers, from forwarders to skidders. A company technician (below) inspects a Bracke 321D disc trencher before shipment to the customer.

A combination of research, digital computer advances, and re-engineering has resulted in significant improvements in Robur Maskin’s equipment designs in recent years. The company’s control system—combined with design changes to its Bracke 321D disc trencher—allows for adjustment of the disc angle, spacing between the implement arms, arm down pressure, hydraulic up pressure on the arms for less ground disturbance, as well as the ability to work intermittently. The hydraulically-driven discs on the disc trencher have a variable disc rotation speed of between five and 35 rpm and adjustable ground pressure of between zero and 568 psi.

The arms and discs are designed to give extensive manoeuvrability both upwards and sideways to reduce strain on the prime mover. Contractors can attach the disc trencher to either a skidder or forwarder with approximately 135 to 200 hp. Production rates will range from .5 to 1.5 hectares per hour depending on terrain and the desired number of microsites per hectare. Accessories include a seeder and micropreparation for seeding. With regard to improvements on the Bracke R390R mounder, adjustments can now be made to ground pressure, width, spacing between arms, locked distance, as well as programming of different mattock wheel lock positions and rotation speeds.

With the control system’s versatility, the mounder can be configured as a multi-functional tool. For example, under a seed tree system, the two side arms can prepare the ground for seed through a process called screefing, while the centre arm can mound for planting. Production rates in standard mounding will range from .8 to 2.3 hectares per hour depending on the terrain and the desired number of microsites per hectare.

Row spacing can vary from 1.2 to 2.2 metres. The longitudinal spacing can vary from two to three metres between each mound. Mound size can also be pre-set for small, medium or large, depending on the site. The recommended prime mover for the B390R mounder is a 140- to 185-hp skidder or 130- to 170-hp forwarder. Mattock wheels come in three- or four-toothed configuration. Robur Maskin also markets the Donaren BD296 two row mounder. It comes equipped with the same control system as on the Bracke mounder and disc trencher, as well as about half the same mechanical parts as the disc trencher.

Its production rate varies from .6 to 1.4 hectares per hour depending on terrain and the desired number of microsites per hectare. The company also offers a smaller TTS 10 series scarifier.

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