Vanguard Magazine

14 AUGUST/SEPTEMBER 2020 www.vanguardcanada.com SUBMARINES area of open water or very thin ice that shifts with the overall ice-pack move- ment. While the exact thickness of ice that a submarine can surface through is dependent of the design of the subma- rine itself, and specific details are under- standably classified, it is almost certainly less than three metres and often less than one metre. Submarines pictured surfac- ing through the ice are fitted with spe- cialized equipment and have searched for an appropriate area to surface, which can often take some time as the ice field is continually shifting. To be clear, a submarine cannot surface whenever and wherever it chooses when conducting under ice operations. 7 • Atmosphere – once a submarine dives it is necessary to monitor the atmosphere and change it as required. In a nuclear sub- marine, a liveable atmosphere is manufac- tured through a very power intensive pro- cess of electrolysis of seawater to produce oxygen combined with the use of carbon dioxide scrubbers. Because the reactor generates sufficient power, this process does not require the submarine to snort. In the case of conventional (including AIP fitted) submarines, the atmosphere is completely changed out when snorting, and although there are abilities to pro- long breathable atmosphere whilst dived, they are necessarily limited. Moreover, should there be a major fire while oper- ating under the ice, all submarines must return to the surface and snort to clear smoke. It is this factor, which precludes non-nuclear-powered submarines from conducting deep under-ice operations, as the time it takes to be able to clear the ice edge, or find a polynya, to either surface or snort is limited by the extant capacity of the battery and the fitted Emergency Breathing System (EBS). Nuclear Power Given the above, one would ask why does Canada not simply invest in a fleet of nuclear-powered submarines? As a nation with a domestic nuclear power genera- tion industry there is no technical reason why Canada could not build and main- tain nuclear-powered submarines. In fact, Canada has investigated acquiring nuclear submarines twice before, and in both cases the Government decided not to proceed because it was unaffordable, as it would have impacted other Canadian govern- ment initiatives. The cost of a nuclear-powered subma- rine fleet is driven by a multitude of fac- tors, notably it is the magnitude of the supporting nuclear infrastructure, not the submarine itself, which determines the overall project costs. During the Canadian Submarine Acquisition Project – SSN in the late 1980s it was the substantial cost of the infrastructure, on both coasts, that whilst remaining submerged, without having to snort. It is important to note that while these systems can dramatically increase the endurance of a low-speed patrolling submarine, their requirement for additional specific fuels significantly limits how long they can operate, as well as, impacting sustainment activities when forward deployed. Therefore, AIP sys- tems are typically not used for long dis- tance submerged transits to and from an operational patrol area. • Nuclear powered submarines produce power by having a nuclear reactor gener- ate heat that is used to create steam in a Pressurised Water Reactor (PWR) sys- tem. 6 The steam is then used to power turbines or turbo-alternators to propel the submarine, as well as, generate elec- tricity (megawatts). Because a nuclear reactor is a true air-independent power generation system, there is no require- ment for the submarine to snort nor carry additional fuel types. Moreover, because the core life of a modern naval nuclear reactor is designed to last the service life of the submarine, submerged endurance is dictated by the amount of food it can carry for its crew. • Ice – a submarine can surface through ice but there are some very finite limita- tions. Typically, when conducting under- ice operations, most submarines surface in what is called a polynya, which is an As a nation with a domestic nuclear power generation industry there is no technical reason why Canada could not build and maintain nuclear-powered submarines. HMCS Windsor operating off Halifax. Photo: Ken Watson.

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