The Titan submersible's shattered remains on the Atlantic seafloor have been completely cleared of all the debris by the recovery ship Horizon Arctic.
The ship's deep-sea robot brought up important parts, as evidenced by the volume of material that washed ashore. The root cause of the Titan's catastrophic implosion, which claimed five lives 11 days ago, may yet be found with the aid of these.
Some of the fragments in St. John's, Newfoundland, were still easily identifiable despite efforts by quayside workers to cover them.
One of the most noticeable was the front titanium end cap from the carbon fiber sub that had a cylinder shape.
The viewport window would have been in the middle hole, giving it the appearance of a metal doughnut.
The lifting sling of the crane passed effortlessly through the gap. The acrylic window's current location is unknown. Its durability and capacity to withstand the pressure at a depth of 4 km had been questioned. However, there is currently nothing to infer from its absence in the St. John's photographs.
What appeared to be the titanium flanges were also brought ashore. These are the metal rings fastened to the carbon fiber hull of the Titan's cylindrical ends. In that case, the end caps would have come into contact with the flanges.
The center of the investigation, which is currently being conducted with US and Canadian authorities, will be the flanges and how they connect to the carbon fiber.
The interface between the acrylic window and the titanium, hemispherical domes or end caps, as well as the location where the carbon fiber would have been bonded to the titanium flanges, are what I think the key parts to look at, according to Blair Thornton, professor of marine autonomy at Southampton University in the UK.
"It's obvious. To advance the investigations, the best we can hope for is that both of those components were recovered, he told BBC News.
A number of bags of trash were lifted onto trucks that were waiting. We don't know what was in them. There might have been fragments of the carbon fiber hull itself.
If there are, investigators will want to look closely at them for any signs that the carbon layers have started to delaminate, especially where they joined the flanges. Extreme conditions may cause carbon fiber layers to begin to separate.
The rear equipment bay was one of the larger landed objects. When diving, it was concealed by a pointed tail cone, but otherwise it was an open cage. The images clearly show that it was severely damaged when it was torn free of the sub.
Look at the long sticking out rod. When the sub was at sea's surface, it would typically use this antenna to connect to the Iridium satellite phone network.
The antenna would have been self-powered, and the lack of communication over this system after the Titan started to dive was a clear sign during the search phase that the vehicle had never risen again.
What's left of the Titan's landing frame, which was used to support it when it was placed on a flat surface, like a workshop floor or its launch barge, are the lengthy metal struts that were lowered onto the ready trucks. The recovered sections would have been fastened to a framework that was fastened to the titanium end rings.
Large white panels made up the exterior cladding or fairing of the submarine. They served as a covering for tubes and wires that ran along the exterior of the carbon fiber hull.
Some people have claimed that these panels are pieces of the actual hull, but carbon fiber pressure vessel pieces would be rigid and black. Contrastingly, as they were lowered onto the truck, these white panels began to bend.
There were no containers that might have been used to transport human remains that we could see being removed from the ship. The US Coast Guard claims that it may already have such materials.