Good access to forests is one of the main challenges in maximising timber mobility. Road construction in most forests, while normally straightforward, can be challenging in steep sites and especially where roads are required to traverse streams and rivers or exit to public roads over difficult terrain.
Grants are available (Table 1) to cover the cost of forest road construction while funding up to €5,000 is available for special construction works (SCWs). These include roads over rivers and streams as well as difficult projects such as building up bell mouth entrances lower than public roads which require additional gravel and stone to allow safe access.
Funding is also provided where forest roads connect to an existing forest road network – State or private – where there is agreement between owners. This is becoming more relevant as the forest estate increases, resulting in greater contiguity of forest properties which will require cooperation between forest owners – State and private – to optimise the forest road network.
Forest roads
Conditions of grant aid for forest roads are outlined in the Forest Roads Scheme, 2015-2020. These include conforming with Department guidelines conditions in documents such as Forestry Standards and Procedures Manual, Code of Best Forest Practice – Ireland, Forest Service Environmental Guidelines and Forest Road Manual, published by COFORD.
To ensure that forest roads are constructed to optimise timber mobilisation, a felling licence number for the area to be thinned and harvested in roaded forest must be included with the application.
Bridge building
One of the main challenges in forest road construction arises when crossing streams and rivers. The Forest Roads Manual: Guidelines for the design, construction and management of forest roads states that where such crossings are unavoidable: “ Forest Service guidelines on water must be observed. Regional Fisheries Boards must be consulted before proceeding with work and Local Authorities may also need to be consulted.”
The manual provides detailed guidelines to ensure that stream and watercourse crossings by bridge, culvert or ford must be designed to meet transport needs and minimise impacts on the site. While fords are still acceptable in certain circumstances, the emphasis is on building culverts and bridges to minimise interference with rivers and streams.
Daragh Little, managing director forestry at Veon Ltd, outlined the challenges and opportunities the forestry company faced in constructing a bridge and forest road in their forest harvesting site near Clonaslee.
A ford had been adequate during the establishment of the forest, “but to facilitate timber extraction, it was necessary to construct a bridge to traverse the River Barrow in a site designated as a Special Area of Conservation,” he said.
“ The bridge went through the normal planning process with significant input from the National Parks and Wildlife Service (NPWS) and local fisheries board.”
Once the bridge was constructed, a road was designed which was grant aided under the Forest Service Road scheme. The company constructed a 900m forest road last November and December, a year after the bridge was constructed. All Veon foresters have project supervisor construction stage (PSCS) certification, which is a requirement for forest road and bridge construction on forestry sites.
Paul Brosnan, marketing director of Veon, described the five main stages in building the River Barrow bridge from planning to completion.
1. Design. The clear span bridge was designed to carry a 16.6m concrete span. Consultation and agreement was reached after discussions with the Forest Service, NPWS and local fisheries board.
2. Abutment construction. The foundations of the bridge were excavated on both sides of the river and abutments constructed with reinforced steel. The concrete was left to cure for 28 days before further work.
3. H-beams installation. These were laid across the river using a crane and shuttering erected.
4. Concrete pouring. Once the shuttering was secured and further steel put in place, the concrete was poured and left for a further 28 days to cure. At all times, the river was protected by covering the bridge carriageway during curing to ensure no splash from the concrete.
5. Hand rails: After curing was complete, handrails were erected on both sides of the carriageway for health and safety reasons.
Grant increase
Special construction works of this magnitude are expensive and could, depending on river width and site topography, run into six figures.
The €5,000 SCW grant, while welcome and adequate for culvert and small bridge construction, is insufficient for large-span projects. These are small in number but it may be worthwhile to fund these up to 50% of bridge construction costs where volume of timber removed and other benefits are taken into account.