Bruce, thanks for posting this link. I was able to view a translation to english by opening the link using Google Chrome browser. The report mentions battery number 3 as problem source.

The Loss of the ARA SAN JUAN has become - as expected - a political football in Argentina with the opposition party blaming the Government and the Navy.

To defend their position, it appears someone on the Government/Navy side of the issue has released my SAN JUAN Assessment.

This came as a hell of a shock to me; however, since my full report is out there, I - for brevity's sake - post the following highlights.

I. Summary Assessment

The explosion of hydrogen generated by the forward battery group – acknowledged by the SAN JUAN to have been water-damaged by flooding through the snorkel mast and experiencing short-circuits – instantly killed the entire crew at about 1330 GMT on 15 November 2017. The explosion – which occurred about one hour and 40 minutes after the SAN JUAN submerged - did not breach the pressure-hull.

The SAN JUAN – still intact - then slowly sank from an intended operating depth of 40m (130-feet) to collapse (implode) at 1351 GMT at a depth of 468m (1535-feet) in 35 milliseconds (ms) with an energy release equal to the explosion of 5216 kg (11,475 lbs) of TNT at that depth. That force was created by the essentially instantaneous conversion of potential energy ((sea pressure of 46.5 bars (684 psi)) to kinetic energy, the motion of the water-ram which entered the SAN JUAN pressure-hull with an estimated velocity of 900 m/s (2000 mph). The acoustic signal produced by the collapse (implosion) was detected by CTBTO underwater sensors as a major source at distances as great as 7730 km (4175 nautical miles).

Collectively, the content of the SAN JUAN messages – the last of which was sent at 1152 GMT - and the CTBTO acoustic data are consistent with a single cause for the tragedy: the explosion of hydrogen generated by water-damaged batteries in the forward group.

V. Conclusions

The apparent inability of the SAN JUAN crew to either surface to send a message or to release an emergency signal buoy is consistent with the conclusion that the event that prevented those actions was instantaneously fatal to the entire crew.

That event is assessed to have been the explosion of hydrogen released by water-damaged batteries in the forward group which built-up to explosive levels over a period of about one hour and 40 minutes from about 1152 to 1330 GMT while the SAN JUAN was submerged and unable to ventilate: exchange the air within the pressure-hull for outside air.

The heat and pressure from the hydrogen event would have been transmitted throughout the entire SAN JUAN pressure-hull in about 30ms (0.030s). The minimum human cognitive recognition time is between 80 and 100ms under optimum conditions.