Vanguard Magazine

design, what then are the limiting factors that define conventional submarine endur- ance? These can be broken down into a number of subsets, as follows: • Fuel - to meet anticipated future mis- sions, the submarine must carry enough fuel for power generation for both pro- pulsion and onboard services. 4 This is not just fuel for diesel generators, it also includes any specific fuel for fitted air- independent-propulsion (AIP) systems, which necessarily includes liquid oxygen. • People - while submarine crews are typically smaller in number than compa- rable surface warships, habitability and adequate food storage will limit effec- tive persistence during lengthy patrols. Using the definition of transit and pa- trol capability provided by the RCN, this translates into a minimum of seven weeks at sea with the ability to extend the time at sea further. Moreover, unlike the surface navy, there is no replenish- ment at sea – you sail with what you have onboard. Thus, food in a submarine be- comes more than simple nourishment, mealtimes break up the monotony of a patrol and are critical to good morale and fighting efficiency. As fresh food typically does not last more than two weeks, everything else must be stored according to pre-prepared menu plans, mainly in freezers. • Waste - people also produce waste and environmental regulations, particularly the MARPOL Polar Code when operat- ing within 12 nautical miles of any ice shelf or fast ice, demand that sufficient onboard waste storage be incorporated into the design. 5 These three factors alone drive the size of the submarine, with Canada's requirements demanding a larger submarine design then those historically operated by European submarine manufacturers where Canada has historically looked to for submarines. Moreover, open-ocean operations require different sea-keeping characteristics than a submarine that is designed to operate in shallower waters of the Baltic, North and Mediterranean seas. In addition to size, there are other fac- tors that determine endurance, specifically the maintenance schedule of the subma- rine and how it is maintained in practice. Once a submarine deploys its ability to conduct defect repair is severely limited, therefore, the material condition of the submarine is critical to mission achieve- ment. To do this, the supporting infra- structure must be in tune with the de- signed maintenance philosophy - whilst being adequately supported logistically, so that maintenance schedules are met with- out inordinate delays impacting subma- rine availability. 6 Pushing a poorly or inad- equately maintained submarine to a high operations tempo will invariably result in limitations of the crew to meet endurance expectations. Furthermore, operating or- phan fleets, that are not in service with an- other navy, further restricts maintenance efficiency, as a common supply chain and platform information sharing can signifi- cantly enhance technical support activities. In short, the submarine must be techni- cally reliable, which is a reflection of both design and maintenance support activities, particularly supply chain. Once deployed on operations, endur- ance can also be measured tactically, in the limitations of the fitted systems. In a HMCS Corner Brook. Photo: Cplc Blake Rodgers, DND. 14 OCTOBER/NOVEMBER 2023 www.vanguardcanada.com decisively shifted to the Asia-Pacific from the Euro-Atlantic. Throughout the Cold War Canadian sub- marines routinely deployed to, and then operated in, the eastern Atlantic (EAST- LANT) and the maritime choke points of the GIUK gap. 3 Today the focus has shifted to the Asia-Pacific and the Canadian Arctic, which involve significantly greater transit distances without external support close at hand. It is noteworthy that Canada's current fleet of Victoria-class submarines were originally designed and built for the British Royal Navy (as the Upholder-class) to transit from the Clyde submarine base in Scotland to the GIUK gap, patrol for three weeks and return. These submarines were never intended for the endurance that Canada required and were only acquired as a stopgap submarine capability extension until such time as a replacement submarine was obtained. Understanding that a Canadian subma- rine will need the endurance normally as- sociated with larger nuclear-powered sub- marines, but in a conventional submarine E N D U R A N C E While modern AIP systems allow for the ability to generate power without snorting, they are all limited by the amount of liquid oxygen carried onboard, which typically reflects less than three weeks of operation.

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