Parks Canada, who are excavating the HMS Terror and HMS Erebus wrecks, have the oldest dedicated underwater archaeology team in the world. Their investigation of the Franklin vessels combines traditional scuba and surface-supply breathing techniques, with the latest high-tech equipment.
Ryan Harris, one of Parks Canada’s senior underwater archaeologists said:
‘ROVs are amazing tools, there are some things machines do well and certainly do better than human beings, but definitely not everything. It’s the appropriate marriage of human and technology that will get the job done.’
The water temperature at the wrecks can drop to -2oC. While divers need special hoses that feed warm water to their suits to stop them freezing, ROVs can stay underwater a lot longer. They also don’t shiver.
The small Deep Trekker ROVs can go deep inside the wrecks and reach areas that are too dangerous for divers.
The team also used new very-high-resolution multi-beam echo sounders and magnetometers to survey the extended debris fields of both sites. Ryan says:
‘We’re continually looking out for newly-developed technologies that might help us …no one tool will work in all environments and in all circumstances. I am able to get much more information from a site when I can get up close and have a tactile experience. Then again, often you can glean hidden details within video footage gained from ROVs that escaped you on the site.’
Over coming years, they hope this combination of human expertise and the latest technologies will reveal why the vessels sank, why they ended up over 72 km apart and even, using DNA analysis, which crew members were the last to leave.