Forest road construction
The key to successful thinning
Forest roads provide crucial access to and within a forest. They assist inspection and management, provide and facilitate forest fire protection, permit economic and efficient timber harvesting and provide recreational opportunities within a forest.
A well planned forest road can also enhance biodiversity in the open spaces between the road and the trees.
For forest owners approaching first thinning, the availability of a forest road suitable for the loading and haulage of logs by timber lorries is crucial.
As the loading of timber is illegal on public roads, even small plantations will require some road construction to provide timber loading areas. This may involve the construction of a new harvest road or the upgrading of an existing road to harvest road standard.
COFORD has published a Forest Road Manual which outlines the guidelines for the design and construction and maintenance of forest roads.
Roads are costly to construct and should be carefully planned and built. Poor design and construction can lead to high maintenance costs and may result in an adverse impact on the local environment.
It is important to plan the best possible access for the extraction and loading of timber before a forest road is developed. A road should be given an adequate period of time (1 or 2 years) to settle before any harvesting operations commences.
The standard tree clearance width for the construction of a forest road is 15 metres.
Proper design will ensure that a long-lasting harvesting road is produced. Impediments such as rock outcrop, aquatic zones and man-made obstacles -for instance ESB wires and gas pipelines- will influence the route of the road. Design methods will depend on the soil type present. Peat sites usually require building on top while a mineral-based soil may be dug out.
Roadside drains and a degree of camber on the road will improve the overall drainage and the control of run-off water and therefore reduce erosion. The design of a forest road is dependent on the intended use.
A bellmouth entrance may be the only requirement on some smaller roadside sites while additional roads and turning areas may be necessary on larger sites.
Construction works should be carried out by competent and experienced contractors. Where possible, road construction should be carried out in the spring and summer to minimize site disturbance. The availability of roading material e.g. stone or gravel on farm will reduce costs. If a road is constructed well in advance of use and allowed to settle, there is less risk of deterioration.
All forest roads will experience wear and tear during harvesting operations. It is important to repair them as quickly as possible. Taking time to plan, design and construct the roads will reduce the maintenance required in the future.