We compare a few parameters for these extraction machines?
Comparisons have become difficult due to the numerous different options and types of each machine that exist. Nevertheless, we have tried to group together a few broad points for each machine.
Comparisons have become difficult due to the numerous different options and types of each machine that exist. Nevertheless, we have tried to group together a few broad points for each machine.
|
Cable skidder |
Grapple Skidder |
Clambunk skidder |
Fowarder |
|
| Purchase costs | Lower | Low | High | High |
| Load size | Small | Larger | Largest | Largest |
| Speed in stand | Fast | Fast | Slower | Slower |
| Manoeuvrability | Good | Good | Not too good | Fairly good |
| Top soil disturbance | High due to lower lift of load | Fairly high, slightly more lift than cable skidder | Fairly low, large proportion of timber lifted | Least as whole load is lifted off the ground |
| Slope down | Relatively steep (<35%) | Relatively steep (<35%) | Steep, as load distribution is good (<40%) | Steep, due to good load distribution (<40%) |
| Slope up | Relatively steep as cable can be pulled to timber and load dropped and winched if required (<25%) | Less steep as must drive to timber and load cannot be dropped (<15%) | Relatively steep due to lower skid resistance of load dragging (<35%) | Steep, due to no skid resistance of load (<35%) |
| Labour requirements | 1 operator, and consideration for chocking and de-choking | 1 operator | 1 operator | 1 operator |
| Loose equipment | Chokers, taglines | None | None | None |
| Log or tree lengths | Preferably tree lengths or full trees (long logs if trees very large) | Preferably tree lengths or full trees (long logs if trees very large) | Preferably tree lengths or full trees | Logs |
| Extraction distance | Relatively short (max 400 m) | Slightly further than cable skidder (max 600 m) | Fairly long distances (max 1000 m) | Fairly long distances (max 1000 m) |
Source: Michal Brink and Andrew McEwan