How large can a naval shell become before crews can no longer handle it manually?
Short answerAbout five inches is the practical limit, with 5.25-inch ammunition marginal and larger shells requiring mechanical assistance.
NotesThe practical boundary is not a single switch between hand loading and automation. Crews can handle ammunition around five inches directly, while 5.25-inch rounds already push the limit. Above that size, machinery increasingly carries the physical load even when sailors still control each step manually. A manually directed loading cycle may therefore rely heavily on mechanical assistance.