Underwater logging?

Triton Logging Inc specialise in logging submerged trees.

Millions of trees are often flooded when new dams are built. These trees are often well preserved due to anaerobic conditions. These trees are quite suitable for use if they can be extracted. Triton Logging is the leader in the design and manufacture of underwater logging equipment. They have their headquarters in British Columbia (Canada), but they operate around the world. The “Sawfish” underwater harvesting system fells and recovers submerged, standing trees.

The Sawfish can work down to any depth, where alternative systems such as grapples or divers can only operate to approximately 25 m (82 ft). It combines traditional timber harvesting with submarine vehicle technology. It uses remote control for precise navigation. It cuts the tree and then attaches an inflatable (reusable) airbag to the tree which floats it to the surface. Multiple cuts can therefore be made without the Sawfish having to return to the surface. One bag is used per tree, which means that the Sawfish must surface approximately every 50 trees.

The Sawfish weights 7000 lbs (3,175 Kg) on land, but is slightly buoyant in water. It is fully remote and uses 8 video cameras and sonar for navigation and positioning. Its power is sourced from a 75 hp (56 kW) electric motor, with biodegradable and vegetable oil based hydraulic fluids. The feller grapple is able to cut trees up to 55 in (140 cm) in diameter. Source: www.tritonlogging.com

Return to Articles