Road Transport Vehicles for Hauling Uncomminuted Forest Energy Products in Sweden

Forestry residues as a renewable energy source are becoming increasingly competitive to fossil fuels. An important issue, however, is effective transportation solutions for this type of material. In this paper we describe and discuss several alternative vehicle systems which have been used in Sweden. We describe and discuss a specialized vehicle for the transportation of loose residues, bundled residues, and tree sections; a specialized stump hauling vehicle; a recently developed vehicle for the transportation of bundled residues; a container system vehicle for stump transportation. All these different machineries have their merits and shortcomings depending on the type of forest energy product. 1. Introduction Concerns regarding climate change and global warming [1, 2] have led to ambitious goals of reducing greenhouse gases due to use of fossil fuels [3, 4]. Many countries have adopted strong policies to reduce harmful emissions. These policies are often implemented by imposing higher taxes on fossil fuels which increase fossil fuel prices relative to alternative energy sources. As a consequence renewable energy sources in general and forest energy products in particular have become increasingly more demanded [5]. In Sweden for instance many central heating and power plants use some sort of forest energy product as input to produce heat or power. According to the Swedish District Heating Association [6], biomass, including processed and unprocessed forest energy products, accounted for almost 50% of the input material for heat production in 2008, a 120% increase from 1996. An important issue, and the one this paper is occupied with, is the logistics involved in the process from harvesting to transportation of the forest energy products to the final user. Forest energy products come in various forms, for example, as residue products from clear cuttings, small trees [7], or stumps [8]. The raw material can be processed in a number of ways before road transport such as wood chips, tree sections, and loose and bundled residues [9–13]. Compared to fossil fuels, forest energy products have lower energy density, which implies that a larger mass must be transported to produce the same amount of heat or power [14]. Moreover, forest energy products can be harvested in many different locations in the forests as compared to fossil fuels which usually have a main extraction point. For the latter, standardized transportation modes, for example, pipelines and trains, can be used while use of trucks, at least initially, is unavoidable for transporting forest energy