Triton Logging Recovers Underwater Forests

According to Triton, there are about 45,000 dams in the world over 100 meters (330’) tall. Most of these dams flooded land at a time when timber was considered a virtually unlimited resource. Clearcutting reservoir areas would have been time-consuming, so the typical practice was simply to flood standing forests; worldwide a timbered area twice the size of New Jersey is underwater. Triton conservatively calculates that over 300 million trees, preserved in the anaerobic underwater environment, are ready for harvest. That translates to 100 billion board feet of timber awaiting only an effective recovery process.

When Triton CEO Chris Godsall began looking at harvesting this forgotten treasure, he immediately identified the need to avoid the dangerous practice of sending human divers underwater with pneumatic chainsaws and, for efficiency and environmental reasons, to avoid the more common practice of pulling a tree up by its rootball. As a result, Triton developed the Sawfish™, which the company describes as “the world’s only deep-water logging machine.” The size of a minivan, the Sawfish is a submarine powered by an electric motor and tethered to a surface barge, where a human operator remotely “flies” it. Rated for depths up to 700 feet (200 m), the Sawfish begins harvesting a waterlogged tree by attaching and inflating one of the 50 reusable airbags it carries. Hovering above the reservoir bottom to avoid disturbing the ecology, the Sawfish grapples a tree trunk with hydraulic arms and cuts it with its 55-inch (1.4 m) chainsaw. Released by the Sawfish, the tree buoys up to the surface to be recovered by a team on a barge as the Sawfish moves to its next target. The Sawfish can harvest over 100 trees a shift, or one every five minutes, surfacing only to replenish airbags; power for the harvester is generated on the barge and transmitted through an electric cable in the tether.