The K-class concept sought submarines fast enough to accompany the battle fleet and submerge during an action to attack with torpedoes. Oil-fired boilers, steam turbines, funnels, and the air paths needed for combustion were a hazardous fit for a hull that had to seal and dive quickly. Even when the machinery produced the desired surface speed, it did not solve the command problem of mixing submarines into a tightly maneuvering battle line. Submarines operate and sense in a three-dimensional undersea environment that surface formations cannot treat like another line of ships. The design therefore arrived before navies possessed a workable doctrine for coordinating the two forces.
Chapter · 53:04-56:43
K-class fleet submarines arrived before workable coordination
The K class sought submarines fast enough to join the battle fleet, but steam machinery and the difficulty of coordinating submerged and surface forces defeated the concept.