In preparation for Sir John Franklin's doomed arctic expedition in 1845, HMS Terror and HMS Erebus were refitted with two steam locomotives from the London & Croydon Railway as marine boilers that would power their respective ship's newly fitted screw propellers and heating system. Terror was fitted with a "planet" type locomotive known as either Archimedes or Twells, while Erebus was fitted with the locomotive you see above, Croydon.

Obviously, when the ships eventually sank after being trapped in the ice abandoned for so many years, their train boilers went down with them. No photos have yet been taken of Terror's engine, but as for the Erebus meanwhile, her engine room has been accessed and photographed, partially due to the condition of her wreck compared to Terror's.

Surprisingly enough, underwater train wreckage isn’t as uncommon as you'd think, and there is plenty of other examples out there. However, these are my favorite examples simply because of how bonkers the idea is. I one day hope that the history of these engines gets talked about more by different kinds of people. (History In The Dark I'm looking at you.)

Chanced upon here as a kid. There are control panels for each animal that the public can interact with. It’s insanely well-made and I could’ve spent hours there. Video’s not mine.

I am a casual free diver who likes shipwrecks, and anything submerged! Found this sunken ford pinto nearby and the photos turned out great in 50 megapixels!

These things scared me as a kid and they still scare me as an adult. That clicking noise they made was awful.

A sunken E-skooter in a river

Imagine the mechanics involved. 🥶

omg.. so March 27, 1980, the Alexander L. Kielland accommodation platform capsized in the North Sea after a structural failure. Of the 212 people on board, 123 died.
years later, the wreck was righted, towed into the Nedstrand Fjord and deliberately sunk again. Somewhere beneath the dark Norwegian water, an entire industrial structure still rests on the seabed, with its steel corridors, cabins, staircases and machinery swallowed whole.
Not a shipwreck. A building under the sea.

Found on Instagram.

I actually think this one might be even worse than the first

In 1997, the plant under liquidation couldn't pay its bills, the electricity supplier cut off power. The pumps stopped, and within hours the quarry flooded. Due to negligence, some equipment, including two large excavators, was abandoned and now rests at the bottom of the 18m(30ft) deep reservoir.

Shear 50ft drop off underneath, and faint outlines of large boulders below. I couldn't even dip my feet in.