Navaleye,
Four Thousand pounds of Sea Water overcame the buoyancy available by blowing all Tanks....Main and Negative and Trim?
As we know of the problem....doesn't that mean the Boat was on the surface or close enough to get off a message to their HQ which in turn told them to return to Port.
Why would the Boat remain submerged or leave the surface knowing they had the problem they did?
It is a US Navy policy that in the event of possible/known contamination of Batteries by Sea Water....the Boat surfaces and remains surfaced. One US Sub did that and actually sent crew members topside while they ran the Aux Diesel to ventilate the Boat.
Admittedly, we do not know of the actual situation and are only relying upon what has been published in News Reports....but from what is being said....a lot of my Submariner buddies are very curious about what did happen.
They also reminded us the "remaining oxygen (breathing time)" being quoted is for the full crew in a single compartment or shared environment. Meaning....if only some of the crew survived and are trapped...but have full access to air and devices to alleviate fouling of the air then there might be a longer period for survival but other issues come into play....being in cold water submerged....it gets very cold.
Background Information on RN Submarines and Snorkeling.
http://rnsubs.co.uk/dits-bits/articl...-snorting.html
Article on the HMS Affray loss.
http://www.hmsaffray.co.uk/portrait_of_a_disaster.htm