I listened to the news on the BBC this morning (broadband connection) and from what they were saying the fire broke out in an electrical panel causing not only loss of life but very heavy damage. One crew member said they only had seconds to get on their EBS masks before smoke spread throughout the boat.

The sheer professionalism shown by these submariners got them through even though there was loss of life. They are very lucky to be alive. Had the fire knocked out the blowing system control and hydaulics that control the planes and rudders as well as the hull valves the entire boat and crew could have been lost.

I also saw some newsreel of the boat on the surface and it was clear that they had no steerage as they were beam on to the very heavy sea.

Both snort and induction masts were raised so it would seem that they at one point tried to line up the ventilation system to help remove the fumes and smoke, that would be a normal procedure. Normally these are raised to run the diesals but can be lined up for ventilation too.

Re the comment about using them to move troops, I cannot see that they could use these for troop transports. Room inside a submarine even a modern one is very tight. During the Falklands war Conqueror carried a small group of SBS south. To do that Part III crew (unqualified submariners) were put ashore to make room for the extra people. Conquerors qualiifed crew was usually 100 plus up to 20 Part III's under training.

A group of 10 SBS was carried. At most they would only be used for insertion operations of special forces.

A conventional boat is very quiet but the life of the battery limits its dived capability time to about 4-5 days before snort-diesaling is needed to charged the battery, a noisy operation and potentially hazardous if you are where you should not be, as a snort induction mast has to be raised above the surface and the exhaust mast raised so it is just below the surface. Depending on sea state the induction can be pooped and it shuts off causing a rather nasty ear popping as a partial vacuum is drawn as the diesals are still running and will suck air in from inside the boat. As an apprectice tiffy I did a number of patrols on the older O class boats operated by the RN. Tight, smelly and uncomfortable, but it was home!

Nuclear powered boats do not need this. The reactor provides both propulsion power and steam power to turbine generators. Yes they are noisier but modern one are covered with anechoic tiles to absorb hull noise.

In tight situations where noise must be kept to a minimum then the reactor coolant pumps are reduced in speed as well as the number operating.

Non essential systems are shut down to reduce load and therefore noise, movement in the boat is reduced and the galley shut down, cold food only. If we knew we were going on what was called a 'sneaky' then we would also have elsan chemical toilets carried on board so that the main heads would not be used and flushed again a potential source of noise.

This could last for several weeks.

Why do people volunteer for submarines well that is a question that is hard to answer. I was volunteered (read pressed) to nuclear boats as they were suffering from a shortage of marine engineers due to the long patrols abd the fact we were always first on and last off because the reactor need to be baby sat even in a shut down state.

I did not want to quite and return to skimmers (surface ships AKA targets) because I belonged to a group of very professional people in an elite service.

No doubt most of the crew of the Canadian boat will go back to sea in submarines. It is just the way submariners are.