I realize this thread is a little more informal than some of the material I have elaborated with, and it is easy for me to see that I am a little more out of place in that regard than virtually everyone else. I could bore most to tears with opinions that go back decades on this thread topic.
The posts show an obvious awareness of the topic, as per the actual events in the Atlantic as opposed to the role of centimetric radar and service entry delays of vessels that could have reversed the outcome, or the stark contrast of resources, tactics, and strategies in the Pacific creating equally contrasted results, so I need not be concerned with the role of a submarine. The growth of this thread in nine days serves to show an interest in the topic, but it probably does not warrant the amount of my free time given to it beyond a little more dscussion here. Forums like this offer some opportunity to exchange views, but in the end it is all conjecture short of a tiny residual that sometimes carrries forward.
Strategic demands always far outpace the rate at which forces can be adjusted to counter them. The Soviet threat and the USSR vanished in a matter of a few years through a combination of fiscal bankruptcy and the passing on of the generation that had been literally bled white during the 'Great Patriotic War'. More recently, the strategic situation changed within an hour or so, just as it had sixty years earlier (the effect on Canada was indirect but nonetheless on a major scale). Strategic changes can and often do take on a nature that would otherwise seem improbable before the fact, especially if only a cursory examination of them is made beforehand. We have had forces in Afghanistan for five years now and have lost 82 and many more seriously wounded to date with a commitment to stay for another 3-4 years. If you had suggested that would be the case on September 10, 2001, you would have been viewed as a complete nutjob, and the government of the day was more than happy to continue to allow the armed forces to disintegrate indefinitely in order to maintain its hold on power through the electorate. Being declared the government by vote does not automatically give it sovereign authority over the land in fact.
If you do not think the minimum effective defence of the north is not important, then you have not done more than a cursory examination of the dangers that lie ahead and the relative ease that they can be countered and forestalled indefinitely. Submarines provide a very potent capacity to deny control over a sea area out of all proportion to their cost and the damage they can actually inflict making them good deterence assets when applied on a limited scale, but building them even in wartime would take years, so what you have in place to assert sovereignty within a few days or weeks will largely be all that you are going to have when it is put to the test.
If not four Arctic submarines, why then four Victoria's? Or twelve ocean frigates? Or Afghanistan? Why not just a part-time militia trained as social workers and armed with an emergency supply of vaseline as like millions of Canadians would advocate? Capitulation is another option as well, or the phased version of it advocated by many in the military so we can concentrate even more power in the hands of the few who know whats best for all of us. What do we need any freedom for if central planning will provide everything we need more efficiently?
Our sovereign rights are viewed with such insignificance that even a California company has claimed oil and mineral rights in the Arctic, claims that would primarily pertain to ocean areas adjacent to Canadian (and Danish) territory. If Canada can develop effective basic forces to defend its own soil, then it will have the forces it needs to ensure an effective role in defence of international stability that also impacts directly on its own safety and security as well. Global wars are driven by the polarizing effect of one or two powers being left to act alone in international affairs, and a middle power like Canada needs the modest capacity at the level of a basic naval task force for which a few additional submarines would be essential ASW assets if it is to have any significant effect.
The irony is that if this small submarine squadron is successful it will never be put to the test. In the process, we will have affirmed our sovereignty and gained possession of the technology to ensure it indefinitely. The vast amount of information to be gained on the topography, currents, tides, and ice conditions on the outer shores as long as Italy or the geology and wildlife present in the inland waterways greater in area than France would have value in being able to decide what could or should not be done in terms of future use of this vast reserve. A half billion dollars was spent on a satellite with a few years service life to provide grainy periodic real time pictures only of the surface and nobody questions that investment, these boats could provide vastly greater amounts of information and maintain surveillance and sovereignty assurance over the region for a longer period of time. The fairweather arctic patrol ships are another half answer typical of institutional thinking and will no more assert sovereignty than CCGS Amundsen and other ships are doing right now. Repeatedly making three quarters of the mortgage payment will lead to foreclosure.
It has been the history of countries for thousands of years that becoming complacent and comfortable with ignoring the basic defence of the soil leads to their end virtually without exception. We had a basic strategy in place for decades up to recent times that made reasonable use of scarce resources to hold the line given the threats of the day, but I see nothing comparable today beyond DND's affinity to the Iron Triangle and the status quo of career interests at home that appear to be at expense of the defence of the soil regardless of the window dressing provided. Through the Arctic, not also the Arctic. Ignoring the primacy of the defence of the soil also will make gaining domestic political support for planning very short lived, and when the Victoria's are gone in fifteen years short of a distinct Arctic submarine design they will not be replaced as will many of the armed forces' remaining assets. The end of the country could follow some decades beyond that before the bicentennial year, just like the end of the USSR and the dozens of countries that have vanished in the last century due to an insufficient critical mass of sovereign power.
There is a lot on the internet and elsewhere concerning fuel cells, but IMHO at least 95% or more of it is hype and much of the rest is theoretical at best. This is not to suggest that the research is not important, since decades from now there may not be much liquid petrolia that is economical to extract, whereas the amount of natural gas reserves are much greater and it may be economically essential in the distant future to employ more efficient means of energy extraction if only to reduce the collective effort diverted to basic living so we have more time for other concerns.
To take one example, there are numerous references to generating hydrogen from aluminum/gallium combinations and using it for so-called green cars. Notwithstanding the fact that it completely ignores the energy needed to generate the metal as well as the fact the gallium is as expensive as silver, it does serve to demonstrate the strong electropositive energy capacity of aluminum by even a simple laboratory demonstration, not to mention the much lower energy content in hydrogen-oxygen bonding. Aluminum is recycled on a large scale because of the electricity cost of smelting fresh material from the source oxide ore.
Aluminum fuel cells have been employed on various test platforms, and it is not a question of making it work, but a question of economics. There is some development needed to improve on the performance, but that development has been slowed by the lack of a unique developed market for it and a lower cost efficiency relative to existing markets that it could offer a substitute to. It will always be easier simply to pull 'ancient solar fuel' out of the ground, but a submarine requires the air to consume it that is scarce below the surface. If the energy cost is higher for the tonnage, then the minimum size should be sought and the bulk of the tonnage required applied to another platform to provide energy economy by size.
The thing to bear in mind is that experimental electric vehicles do not compare directly with use in a submarine. Aluminum fuel cells can be located outside the pressure hull, whereas a diesel engine can not. Lead acid cells are heavy, whereas aluminum fuel cells would consume less of the available displacement margin. Ships are more efficient transport vehicles relative to trucks, planes, and trains, submarines are even more efficient than surface ships. Apples and broccoli may be good for you, but they are good for you for much different specific reasons.
It would not be a cakewalk to develop the propulsion system for a submarine, but it does not require large engineering concerns to develop workably sized proton exchange membranes and similar new technologies. Not to denigrate some of these large multinational companies, but a large part of their motivation has to do with acquiring monopolistic control over future technologies. Other companies and militaries will not go near such development as well because it conflicts with their own interests; don't hold your breathe waiting for the nuclear submarine group to find alternate forms of propulsion, since they will not undermine their own future cash flows or perceived dominance at sea. A crude aluminum fuel cell can be made with little more than a piece of foil and some common household alkalis; good luck with the hydrogen-oxygen fuel cell and the nuclear reactor for the car, eh. We have a few submarines to take the technology to sea under realistic conditions to provide reasonable cost estimates and the opportunity for design refinements that are scaleable to a full submarine.
Mention of the Type 212 AIP was made in an earlier post primarily to underscore the state today of more difficult technologies and of the reduced complements of the latest generation of boats. I can't offer any definite numbers here because the data has not been developed to an applicable form or it is restricted or classified for obvious reasons. The Type 212 AIP 'Sans Hydrogene' would offer a last resort fall back position, but it has serious dangers and deficiencies associated with it. The volatile oxygen offers the always present dangers of another Kursk and the score of British high-test peroxide torpedo explosions nor is the power available anything more than a minimum. Aluminum is a much denser, powerful, and safer fuel that does not need large quantities of oxidant to work. It likely will be an important technology in the future as volumetrically oriented armoured vehicles reach obsolesence around the 2050 timeframe as well, and a new form of prime mover will be required to work with more expendable component hardened vehicles. With aluminum expertise in eastern Quebec, aerospace expertise to the west, and small submarine expertise on both coasts, there would be enough to consider a clean sheet of paper as one of a range of options.
Detailed empirical estimates can be off by wide margins, but by lengthy calculations made long ago there was the potential evident for a propulsion system that could rival nuclear boats. Don't ask for them now, the basic numbers were lost a long time ago during the long periods of sovereignty abrogation of previous governments, nor would I have full confidence in them since too many assumptions would have had to have been made in the process. In the real world, unforeseen problems can greatly reduce the end effect, but even with greatly degraded performance levels they would still be more than adequate.
I would elaborate on my qualifications to make such calculations, but the details would present as boisterous, and that is not in my nature. It would be beside the point as well, since this is not about me. I have never had the time, money, or reason to tinker with such an applied electrochemical device (and have bigger priorities than such a things), but others have built forms of them for other uses, and as a matter of intuitive insight I am of the opinion that it is the only practical proposition.
In the end it comes down to the people currently engaged in the exercise; the money will come if they do the job right. Reduced to a brochure reading exercise while exhorting phantom sub recon game theory, the project will come to nothing.