Implosions and scientific realities

Q: What is implosion? How can it destroy a sub like Titan?

Krishna: Implosion is an opposite of explosion. In an explosion, the force acts outwards, but in an implosion the force acts inwards. Implosion is a process in which objects are destroyed by collapsing (or being squeezed in) on themselves.

Explosion and Implosion

True implosion usually involves a difference between internal (lower) and external (higher) pressure, or inward and outward forces, that is so large that the structure collapses inward into itself, or into the space it occupied if it is not a completely solid object. Examples of implosion include a submarine being crushed from the outside by the hydrostatic pressure  of the surrounding water and the collapse of a massive star under its own gravitational pressure.

When a submersible is deep in the ocean it experiences the force on its surface due to water pressure. When this force becomes larger than the force hull can withstand, the vessel implodes violently.

Implosions, like explosions, are very violent. As the hull breaks apart under the huge external pressure, a large amount of energy is released. It would have killed all the occupants instantaneously.

The key is the design of the hull that protects the vessel against the large external water pressure that is trying to crush the hull. Much of the existing technology is based on steel, titanium and aluminum. The performance of these materials under extreme stress is well understood.

However, the Titan's hull had an experimental design. It used mostly carbon fibers, which have the advantage of being lighter than titanium or steel, so Titan could have more space for passengers.

Properties of carbon fibers for deep sea applications are, however, not that well understood. It can crack and break suddenly. Also, Titan had previously gone for deep sea dives a few times, which would have contributed to the fatigue of the hull to make the hull more prone to catastrophic failure.