I dunno mate, I didn't build it like.But what mechanisms were these? It has no actual ballast tanks on the sub itself, they are on a different platform. I have heard people say they can use balloons but how are they inflated, where are they stored, at what depth do they work and at what pressure? They were operating in over 3800 meters of water. They would need a hell of a system that works at greater than 380 bar to work that deep. What’s the failsafe weight, how would that work?