In addition to chipper-forwarders, there are now commercially available machines capable of harvesting, self-feeding, chipping, and transporting woody biomass. Though not commonly in use, these machines have the advantage of performing “single pass” utilization of thinned materials, when larger diameter (e. g., >5-inch DBH) must be processed.
14.7 Woody Biomass Transportation
Along with harvesting and processing costs, transportation costs are a major determinant of the delivered cost of woody biomass. Even after communition or compaction, woody biomass tends to be bulky and difficult to transport efficiently. The preferred approach, when possible, is to maximize net payload by using the largest trailer possible. For example, high — capacity chip tractor-semi-trailer combinations, also called chip vans, can exceed 19 m in length, 45 000 kg in gross vehicle weight, and 30 000 kg in net payload. Large payloads distribute the fixed costs of transportation over a larger amount of material and generally, though not always, result in greater input/output efficiency in variable costs, such as fuel consumption. Larger payloads also reduce operational delays associated with the loading and unloading of many small trucks compared to loading fewer large trucks. Though ideal from an operational standpoint, a number of factors constrain the use of these vehicles in woody biomass logistics.
