Forget Franklin and his crew, the ships themselves were extraordinarily interesting! The Canadian Parks service has a video online of their exploration of the Erebus, and the link is provided below, but here is a short summary of the characteristics of the ship.
After sending an aquatic robot down to explore the remains, a few courageous went diving to the bottom of the ocean to explore the ruins more thoroughly. They had to be very careful with their air hoses and equipment to make sure that none of the ship was damaged as they explored.
The first thing that they analyzed were the guns onboard the ship. This prompts the question… why were they carrying such massive guns on an arctic exploration? Although there were such dangerous things as polar bears and perhaps hostile tribes (for lack of a better term for the groups of people living there), canons seem a bit excessive… and they seem to be a lot of weight to carry for an expedition trying to conserve space. The answer lies in the ships original purpose- it was a royal navy ship, and as such, it was equipped the minimal required arsenal. In reality, if the two ships had found the passage, they were meant to return to England via the Pacific, and since they didn’t know what sort of dangers they might encounter, they were equipped with high powered guns… just in case.
In the stern of the ship, there was a stern post and a rudder post. Perhaps one of the most interesting things about this ship is that the Erebus and the Terror were a couple of the first two ships to have a screw propeller for polar navigation. The ship was carrying 12 days of coal, and the crew was told to only use the steam engine when there was no wind for their sails, or if they had to get through a temporary passage in the ice. Because they didn’t want to have the propeller in place all the time (in the water, it would just slow them down), so there was a mechanism in the stern to allow them to raise and lower the propeller in and out of position. When they were wintering over in the arctic, the ice couldn’t rip away the propeller.
On the quarterdeck, (which is now covered in kelp) the officers controlled the ship. There was a skylight that looked down into the room where the senior officers would have taken their meals- the higher officials, the captains, lieutenants, and medical officials, for instance. Beside the skylight, there was the ship’s tiller. This allowed the ships helm to attach to the rudder in order to steer the ship. It’s made out of bronze, and is quite strong. When they added the propeller to the Erebus, they actually needed to lengthen the ship a little bit, and with that, they needed to lengthen the connection to the rudder- they did so with bronze.
The tallest point on the remains of the HMS Erebus was a capstan, a revolving cylinder that would turn on its axis, and it was used to manage cables from the sails and other things used for steering. The capstan was also used for retrieving the ship’s heavy anchors. The tallest of the three masts was broken off from the ice.
The bilge pump remains intact. All wooden ships take in water, and if the water isn’t pumped out regularly, the ship will sink. They guess that the ship actually sank because, after the crew abandoned it and the ice broke free, there was no one to pump the water out of the ship, and so it just sank to the bottom.
Link to the video, enjoy!: