What is a ‘Catastrophic Implosion’?
We can assume the implosion actually happened on the first day of the dive – but perhaps not exactly at the same time communication was lost with the mothership. But why did it happen?
Most, if not all, submersibles and submarines operating at depth have a pressure vessel made of a single metallic material with high yield strength. This is typically steel for relatively shallow depths (roughly less than 300m), or titanium for deeper depths.
A titanium or thick steel pressure vessel is usually a spherical shape that can withstand the crushing pressures you might expect at 3,800m – the depth at which the Titanic wreck lies.
The Titan, however, was different. Its pressure vessel was made of a combination of titanium and composite carbon fibre. This is somewhat unusual from a structural engineering perspective since, in a deep-diving context, titanium and carbon fibre are materials with vastly different properties.
Titanium is elastic and can adapt to an extended range of stresses without any measurable permanent strain remaining after the return to atmospheric pressure. It shrinks to adjust to pressure forces, and re-expands as these forces are alleviated. A carbon-fibre composite, on the other hand, is much stiffer and does not have the same kind of elasticity.
We can only speculate about what happened with the combination of these two technologies, which do not dynamically behave the same way under pressure.
But what we can say almost certainly is that there would have been some kind of loss of integrity due to the differences between these materials. A composite material could potentially suffer from “delamination”, which leads to a separation of the layers of reinforcement.
This would have created a defect which triggered an instantaneous implosion due to the underwater pressure. Within less than one second, the vessel — being pushed down on by the weight of a 3,800m column of water — would have immediately crumpled in from all sides.