Heathrow Harry
Initial reports from the Argentine Navy indicate that they had a problem with their snorkle which allowed water to enter the hull and shorted out the forward battery. What transpired after that to cause the sub to sink is only speculation at this time. As the author of this report indicates, it's not beyond the realm of possibility that the forward battery exploded.
That acoustic signal originated near 46-10S, 59-42W at 1358Z (GMT) on 15 November 2017. It was produced by the collapse (implosion) of the ARA SAN JUAN pressure-hull at a depth of 1275-feet. Sea pressure at the collapse depth was 570 PSI. The frequency of the collapse event signal (bubble-pulse) was about 4.4 Hz.
The energy released by the collapse was equal to the explosion of 12,500 pounds of TNT at the depth of 1275-feet. That energy was produced by the nearly instantaneous conversion of potential energy (sea-pressure) to kinetic energy, the motion of the intruding water-ram which entered the SAN JUAN pressure-hull at a speed of about 1800 mph.
The entire pressure-hull was completely destroyed (fragmented/compacted) in about 40 milliseconds (0.040s or 1/25th of a second), the duration of the compression phase of the collapse event which is half the minimum time required for cognitive recognition of an event.
What I don't understand is, if the boat took on water through the snorkel which led to a battery short then a possible explosion in the forward battery bay, why would it implode ?
A cylinder filling with water from an explosion is then not going to implode with the force being described in the article, and if filled with sufficient water to over come the blast tanks and sink then the amount of water involved would surely cause the inside hull pressure to start equalising near to the outside pressure.
An explosion in the forward battery bay opening up the hull and sinking rapidly to the bottom would make more sense.