Field Note March 2011 Road rehabilitation in the Normandy operating block, Caribou Forest Site Brad Sutherland Senior Researcher In July 2010, FPInnovations visited a road rehabilitation site northeast of Sioux Lookout, Ontario, in the Caribou Forest. The area is operated by AbitibiBowater Inc. Disc trenching and regeneration of roads conducted in the northern portion of the Normandy operating block in 2005 and the southern portion in 2010 were investigated. Objective Roads in the northern portion of the Normandy operating block were decommissioned by permanently blocking vehicle access in 2005 through the removal of water crossing structures and with an excavated berm at the block entrance. In addition, road surfaces were disc trenched to facilitate regeneration, and seeded or planted to jack pine to rehabilitate to forest conditions similar to that of the adjacent regenerated cutblock. Remaining roads in the southern portion of the Normandy block were disc trenched in July 2010 and will be regenerated to jack pine in 2011. Road decommissioning was conducted to meet tourism requirements while the regeneration of road surfaces addressed caribou management guidelines. The objective of FPInnovations visit was to document current practices of road decommissioning activities in Ontario. Details of the operations In July 2010, road surfaces were disc trenched using two TTS-35 passive disc trenchers mounted on John Deere 748 and Timberjack 660 skidders. The operating technique was to travel one way down the road in a zigzag path, and then return, crossing over the original path, resulting in a double-helix final pattern (Figure 1). Treated roads that are easily accessible will be planted to pine in 2011, while more remote portions of the block will be aerially seeded. Figure 1. Site preparation of main road with a disc trencher using a double-helix pattern. In 2005, roads in the northern portion were disc trenched using the same equipment and zigzag pattern as observed in 2010. As the treatment was exploratory, a portion of the treated roads was aerially seeded to jack pine (Figure 2) and the other portion was planted with jack pine container stock (Figure 3). Productivity Disc trencher productivity on block roads was approximately 600 m of road per hour to produce the double-helix pattern. 1
Observations and comments Depth of disc trencher furrows was variable and appeared deepest on branch roads (approximately 10 to 20 cm deep) where there was no additional aggregate added to the sandy parent soil. On main roads where a built-up aggregate base course was evident and the level of road traffic higher, furrow depth was shallower (approximately 5 to 10 cm deep) even though the contractor indicated that both trenchers were used on main roads in an effort to penetrate the compacted road surface. Each trencher produced a double-helix pattern. The contractor responsible for the disc trenching felt that any towed implement such as a passive or powered disc trencher cannot achieve adequate disc penetration on high-traffic main roads with compacted aggregate base-course layers. In addition, the equipment is subject to greater wear and tear on skidder tire chains, trencher disc bearings, and teeth than would be expected from use on low-traffic branch roads where little or no gravel has been applied. In a case study of landing rehabilitation in central British Columbia, disc penetration depth averaged 30 cm using a powered disc trencher following double passing over the same furrow (Sutherland 2000). Soils in this study did not have an aggregate surface applied but were highly prone to compaction due to the presence of finer textured silt and clay particles. Figure 2. Pine regeneration showing variable results four years after seeding of disctrenched main roads. Regarding the relative success of planting versus seeding, the stocking to pine on branch roads that were disc trenched and planted in 2005 appeared noticeably higher and more consistent in 2010 than with seeding on the main roads. With less compaction and built-up aggregate layers than on main roads, Figure 3. Pine regeneration four years after container branch roads can offer a more favorable microsite for regeneration. In addition, planting of disc-trenched other variables can affect seed germination and survival in any given year. branch roads. Therefore, relative comparisons of success between the two alternatives for regeneration of rehabilitated roads can be difficult to make. In choosing between the option to plant or seed decommissioned roads, access to road systems that are closed and have water crossings removed can present an obstacle to planting crews thus making aerial seeding a more attractive and less costly alternative. Road surfaces are a harsh environment for seedling establishment, so any treatments that can improve microsite quality such as tilling or the addition of organic material prior to seeding should improve the success of regeneration efforts. References Sutherland, B. 2000. Comparison of five treatments used to rehabilitate compacted landings. For. Eng. Res. Inst. Can. (FERIC), Vancouver, BC. Advantage 1 (16) 12 p. Contact: brad.sutherland@fpinnovations.ca FPInnovations would like to thank the Ontario Ministry of Northern Development, Mines and Forestry for providing funding support for these field visits and AbitibiBowater Inc. for their cooperation in providing background information for this Field Note. 2
Field Note March 2011 Site Road rehabilitation on Wind Road, Lac Seul Forest Brad Sutherland Senior Researcher In July 2010, FPInnovations visited a road rehabilitation site north of Sioux Lookout, Ontario, near Upper Wapesi Lake in the Lac Seul Forest. The area is under a Sustainable Forestry Licence to McKenzie Forest Products Inc. of Hudson. Ripping of branch roads and recontouring of gravel pit activities were investigated. Objective Upper Wapesi Lake is a remote tourist outfitter lake where the current forest management plan for the area requires that roads within a buffer zone surrounding the lake be decommissioned to prevent vehicle access. Roads immediately adjacent to the lake would be rehabilitated to forest conditions similar to that of the adjacent cutblock. In addition, drainage structures along Wind Road were removed to meet caribou management guidelines and gravel pits were recontoured and cutbank edges removed to meet safety requirements and improve aesthetics. The objective of FPInnovations visit was to document current practices of road decommissioning and rehabilitation activities in Ontario. Details of the operations Approximately 10 km of branch roads were ripped using a single standard ripper tooth on a Caterpillar D8N crawler tractor (Figure 1). The operating technique was to rip to a depth of approximately 1 m down one side of a block road and return on the opposite side (Figure 2). Aerial seeding of jack pine would be conducted on the ripped roads the following spring. Figure 1. Standard ripper used for 2-pass road ripping. 1
Figure 2. Branch road treated with two passes of a ripper tooth. Gravel pits in the area were recontoured using a crawler tractor and blade to remove over-steepened banks and achieve a more natural angle of repose. A Caterpillar 330 CL excavator with standard bucket was used along pit edges to minimize disturbance of pine regeneration. Productivity Ripper tooth productivity was approximately 750 m of road per hour on branch roads using a double pass. Observations and comments The goal of the ripping treatment was to decompact roads and produce a roughened surface. Ripping to a depth of 1 m will fracture the road surface and substrate thereby improving infiltration and allow easier root penetration from regenerating seedlings. On the cohesive soils (sandy clay) observed on the branch roads, ripping produced a pronounced berm. This raised and roughened surface provides shade that will enhance the microclimate for vegetation growth. It is expected that ripping in sandy soils without the clay fines present may not result in the same degree of disturbance. This is a consideration if one of the goals of ripping is to prevent vehicle access. In terms of adequate machine size needed for ripping, the operator indicated that in these heavier soils, the D8 was lugging in 1 st gear using the single ripper tooth at full depth. Multiple ripper teeth may be considered to improve the efficiency of ripping operations, but horsepower requirements to achieve the desired depth and degree of disturbance will dictate the minimum prime mover size category required. A case study of road rehabilitation of forest roads in Alberta and Saskatchewan highlights examples of several different ripper tooth configurations (Sutherland and Gillies 2001). References Sutherland, B.; Gillies, C. 2001. Rehabilitation of temporary forest roads in Alberta and Saskatchewan. For. Eng. Res. Inst. Can. (FERIC), Vancouver, BC. Advantage 2 (6) 11 p. Contact: brad.sutherland@fpinnovations.ca FPInnovations would like to thank the Ontario Ministry of Northern Development, Mines and Forestry for providing funding support for these field visits and McKenzie Forest Products Inc. for their cooperation in providing background information for this Field Note. 2
Field Note March 2011 Road decommissioning and rehabilitation near Jorick Lake, Lac Seul Forest Location Brad Sutherland Senior Researcher In July 2010, FPInnovations visited a road decommissioning/rehabilitation site approximately 40 km southeast of Sioux Lookout, Ontario, near Jorick Lake in the Lac Seul Forest. The area is under a Sustainable Forestry Licence to McKenzie Forest Products Inc. of Hudson. Excavation for road closure and brush raking, as well as rehabilitation of branch roads were investigated. Objective Jorick Lake is a remote tourist operator lake where the current forest management plan for the area requires that road access within a buffer zone surrounding the lake be decommissioned to prevent vehicle access. Roads immediately adjacent to the lake would be rehabilitated to forest conditions similar to that of the adjacent cutblock. The objective of FPInnovations visit was to view the state of the rehabilitated roads four years after treatment. Details of the operations Block road surfaces in the buffer zone were bladed to a maximum depth of approximately 60 cm with a brush rake mounted on a Caterpillar D8 crawler tractor in December 2005 followed by helicopter seeding to jack pine in March 2006 (Figures 1 and 2). Figure 1. Road screefing with a brush rake (Photo courtesy of McKenzie Forest Products Inc.). Figure 2. Pine regeneration on brush-raked roads four years after aerial seeding. Road closure to the area was completed in October 2006 using a Caterpillar 330 excavator with a standard bucket and live thumb. Two operating patterns were employed. On road surfaces within the buffer zone, a 1
five-of-dice pattern (four scoops outlining a square plus one scoop in the middle) was repeated along the road surface (Figure 3). At the entrance to the block, a culvert water crossing was removed and the operating pattern was switched to a series of cross-berms on the road approach to the crossing. Logging debris including stumps from roadside slash piles was included in the berms of all excavated surfaces. Productivity Figure 3. Road decommissioning with an excavator using a five-of-dice pattern. Scarification of road surfaces with the brush blade consisted of two passes (out and back) to achieve complete coverage. Productivity was estimated at 1000 m of road per hour. Excavation of the road using the full depth of the excavator bucket and the five-of-dice pattern resulted in a productivity of 500 m of road per hour. Observations and comments The decommissioning of roads with a brush rake was exploratory in this case study. Brush rakes are typically designed to pile brush on the ground surface and lightly scarify surface organic layers for pine regeneration. According to company staff, decommissioning packed road surfaces proved challenging with a brush rake. A more robust design and possibly different tooth configuration may have improved the suitability of this implement for the task. Rather than undertake such modifications, the company has opted to conduct road decommissioning with either an excavator, a disc trencher, or crawler tractor mounted ripper tooth. Excavator berms and scoops proved to be an effective barrier to vehicle entry into the block as there was no sign of vehicle travel four years after treatment. Further, after four years of settling, the hummocky surface still presented a major deterrent even to foot travel. Immediately following the excavation treatment, it was felt that the treatment depth and spacing was probably excessive and that a shallower depth and wider spacing of excavated berms and scoops would prove adequate as a barrier. Reducing the intensity of the treatment in this manner should reduce costs through increased machine productivity. Identifying the minimum effort or intensity of road decommissioning required to prevent access is a case-specific challenge that can involve a number of factors. Contact: brad.sutherland@fpinnovations.ca FPInnovations would like to thank the Ontario Ministry of Northern Development, Mines and Forestry for providing funding support for these field visits and McKenzie Forest Products Inc. for their cooperation in providing background information for this Field Note. 2
Field Note April, 2012 Site Removal of water crossing structures on the Wind road, Lac Seul Forest Brad Sutherland Senior Researcher In July 2010, FPInnovations visited a road decommissionning site north of Sioux Lookout Ontario near Upper Wapisi Lake in the Lac Seul Forest. The area is under a Sustainable Forestry Licence to McKenzie Forest Products Inc. of Hudson. Culvert and bridge removal and stabilization against erosion and sedimentation activities were investigated. Objective Upper Wapesi Lake is a remote tourist outfitter lake where the current forest management plan for the area requires that roads within a buffer zone surrounding the lake be decommissioned to prevent vehicle access. As part of rehabilitation measures to meet caribou management guidelines, drainage structures were removed along Wind road to block access to the area. These locations were then stabilized to reestablish natural drainage patterns and minimize erosion and sedimentation to water courses. The objective of FPInnovations visit was to document current practices of road decommissioning and rehabilitation activities in Ontario. Details of the operations Culvert removal included back spreading of fills onto the road surface on either side of the crossing using a Caterpillar 330 CL excavator with a standard bucket and live thumb. Woody debris from nearby slash piles were spread along stream banks for erosion control, and newly disturbed soil surfaces were hand seeded with turf lawn seed mix (Figure 1). Where road approaches were sloped down towards decommissioned crossings, water bars were constructed using an excavator to divert road surface runoff onto the adjacent forest floor for filtering of sediments (Figure 2). Removal of the temporary bridge involved lifting decking panels and carefully sliding stringers off of cribbing using an excavator (Figures 3). Cribbing was left intact to maintain the stability of stream banks (Figure 4). Exposed soils around cribbing were seeded and water bars constructed on crossing approaches. At the beginning of the road system, a berm was constructed to block vehicle access just before the first decommissioned water crossing. Figure 1. Water crossing with rock and woody debris armouring following culvert removal. 1
Figure 2. Water bars constructed on approach to newly removed culvert crossing. Productivity Figure 3. Removal of deck panels from a 12 m span bridge. Figure 4. Cribbing left intact to stabilize banks following removal of decking and stringers. The 12 m span bridge removal observed during the site visit required 135 minutes and included removal of four deck sections and stringers using the excavator, cables and chains, loading of these components onto a flatbed, hand seeding one approach, and constructing one water bar. I-beam stringers were held in position at each end on the sill plates of the support cribbing using rebar rods embedded in the sill plate. Prior to sliding the I-beam structure off of the cribbing, the four rebar attach points were cut to facilitate stringer removal without disturbing crib structures. Cutting was done manually with a hack saw and required 60 out of the total of 135 minutes. The site foreman estimates that typical removal times for decommissioning a crossing with a 12 m bridge is approximately 1.5 hours. Decommissioning a culvert crossing requires approximately 1 hour for culverts up to 1500 mm diameter and approximately 2 hours for culverts between 1500 and 2000 mm diameter. Observations and comments The excavator operator indicated that a 330 size-class machine was required for this type of work to offer the counter weight needed to handle bridge stringers and the reach height necessary to load stringers onto the flatbed. Using temporary bridge structures is more cost-effective than dismantling a permanent structure while leaving the cribs in place. Water bars are an inexpensive solution to block access and redirect water flow and could be built at multiple locations on the approaches to a water course, especially on long grades. Contact: brad.sutherland@fpinnovations.ca ------------------------ FPInnovations would like to thank the Ontario Ministry of Northern Development, Mines and Forestry for providing funding support for these field visits and McKenzie Forest Products Inc. for their cooperation in providing background information for this Field Note. 2