Table 1. Costing example for single-machine systems (SMS) versus two-machine systems (TMS) on small tracts in Sweden. In this example, the assumed relocation cost per tract per machine was €400. The logging cost was assumed to equal the Swedish national average for clearcutting during 2023.
Machine system Tract size / Volume per harvesting site (m3) Total relocation cost per machine system (€) Relocation cost
(€ m–3) 		Logging cost
(€ m–3) 		Total logging cost including relocation (€ m–3) Relocation costs’ share of total logging costs (%)
SMS 50 400 8 13 21 38
100 400 4 13 17 24
200 400 2 13 15 13
300 400 1.33 13 14.33 9
400 400 1 13 14 7
TMS 50 800 16 13 29 55
100 800 8 13 21 38
200 800 4 13 17 24
300 800 2.66 13 15.66 17
400 800 2 13 15 13
1

Fig. 1. Previous examples of large single-machine systems (LargeSMS): A) harwarder (Komatsu X19 prototype during unloading using a loading grapple); B) dual machine (Ponsse Buffalo Dual in harvester mode). A harwarder processes the logs directly onto the machine’s load space (termed direct loading), while a dual machine initially works as a normal harvester and processes the logs into piles on the ground. Thereafter, the dual machine converts into a forwarder, loads the logs from the ground, and forwards them to the landing. Photos: Rikard Lundqvist (A) and Ponsse Plc (B).

2

Fig. 2. Examples of quick coupling technology on: A) the Komatsu X19 harwarder prototype and; B) the Fibredrive 1750 harwarder prototype. Quick coupling technology increases the competitiveness of single-machine systems (SMS) compared to two-machine systems (TMS) by reducing the time needed to switch between harvesting heads and loading grapples on both harwarders and dual machines. This reduction in time consumption allows for more efficient work methods and/or raises the SMS’ machine utilization. Photos: Rikard Lundqvist (A) and Back Tomas Ersson (B).

3

Fig. 3. Rotatable and tiltable load spaces/bunks on previous SMS (Valmet 801 Combi harwarder and Fibredrive 1750). These types of bunks allow for efficient direct loading, efficient unloading, and semi-automation on SMS. Photos: Skogforsk (A) and Back Tomas Ersson (B).