Submersible Build Log

Ambient Model 1

Ambient Design 1

This is a 1:10th scale model being tested in the sea.

I was trying to use the very basic diving bell idea, but have large soft tanks all round to give it a good amount of freeboard when surfaced.  The idea was to be able to have a top hatch, so you wouldn't have to swim in from the underneath.  This model was very stable both on the surface and underneath.  The lead weight is just out of the picture underneath. The main tanks are flooded and the model is neutral at this point.  You can just see the fishing float sticking out from underneath that gives an indication of the level of cabin air.


The real one was going to have an automatic pressure compensation system combined with a series of vent holes in order to try and keep the level of cabin air constant to maintain neutral buoyancy.  There was to be one hard tank to fine tune buoyancy.


The soft tanks were this shape in an attempt to allow water to fill the tanks around the centre at first.  This was to keep the centre of buoyancy (COB) as close to the metacentre as possible in the transitional period from surfaced to submerged.  


It might have worked if the water was FLAT calm, but proved unstable.  Due to wave action, the centre of buoyancy moves around and there is a point where water sloshes to one side, causing a dramatic change in COB and an unacceptable list. Not enough to completely overturn the model and spill cabin air, but not really acceptable.


Once underwater however, COB is well above COG and the model is in fact now very stable again, even if shoved really hard, it was very difficult to upturn.