Economics of a hydraulic hammer for forest road construction in a mountainous area
This research deals with productivity and cost of rock disintegration and side casting of materials with the use of a hydraulic hammer mounted on a PC 220 Komatsu crawler excavator, which is used on rocky slopes of Hyrcanian forests of Iran. A continuing time study was applied during the road construction. To estimate the volume of rock disintegration, the average end area equation was used. The increasing cut-slope height decreased productivity. The productivity of hydraulic hammer averaged at 5.5 m<sup>3</sup>·h<sup>–1</sup> for the mean work volume of 5.07 m<sup>3</sup>·m<sup>–1</sup>. The unit cost of the system was 7.7 €·m<sup>–3</sup>. From the economic point of view a new machine with multipurpose system could be recommended for forest road construction operations in rocky areas.