A common submarine built between the Oberon and Upholder generations could not be a short-range coastal boat. Britain wanted conventional submarines able to support special operations toward the Arctic, while Canada needed a design that could move between widely separated coasts and work near the ice. Australia imposed its own demand for very long Pacific transits. Ice-strengthening and the ability to reach thinner ice for air would matter if a diesel-electric boat entered northern waters. Air-independent propulsion is raised as a possible way to reduce the frequency of surfacing, although the machinery still sets hard limits. The three navies arrive at a shared long-range requirement for different geographical reasons.
Notable Point · 3:36:03-3:42:31
Why a Commonwealth SSK would need exceptional range
British Arctic missions, Canada's two-ocean geography, and Australia's Pacific distances all push a shared conventional submarine toward long endurance.