The answer is as follows: a) The engine room in the Victoria class submarines contains large diesel engines that operate, when required, in a confined space that receives minimal cooling air. Like all the machinery rooms in Canadian warships operating under tropical conditions, the peak temperatures were uncomfortable. Submarines pose the greatest challenge in this regard, since, by design, they do not have regular access to outside air. For this reason, along with most modern machinery spaces, the Victoria class submarines have an automated engine room and the need for the continuous presence of engine room operators is limited.
b) This was the Canadian Navy’s first experience of operating a Victoria class submarine under tropical conditions. The data collected to date suggests that the environmental conditions, tropical or temperate, do not significantly influence the engine room temperature since the majority of outside air introduced to the space is devoted to supporting combustion in the diesel engines. Thus, the cooling and heating effects of outside air is limited.
c) The highest temperatures were recorded in the tropical environment immediately after the diesel engines were stopped and the submarine dived to its operational depth. The peak temperatures were also recorded in the highest part of the compartment adjacent to the hot engine exhaust manifold.
d) The temperatures experienced within the engine room in tropical conditions are not unique to the Victoria class submarines. They are consistent with temperature levels experienced in many diesel-electric submarine engine rooms.
e) Safety of the crew was of paramount importance for the commanding officer and crew exposure to the engine room temperatures was managed by the submarine’s physician assistant. There were no heat stress related injuries during the transit.
f) The transit demonstrated that, although at times uncomfortable, the Victoria class submarines can safely operate in a tropical environment. The Navy will continue to examine options for improving localized equipment cooling, air conditioning, and living conditions within the submarines as future deployments may include operations in tropical areas of the world.
g) Since the engine room is automated, it is not a priority for major modifications to reduce the temperature under either temperate or tropical conditions. Options for improving the comfort in the accommodation spaces and operating stations are currently being considered. Working conditions in the engine room will be monitored and the crew’s exposure to high temperatures will be managed in the same manner applied to many of our Canadian Forces members serving around the globe under similar conditions.