Shipyards need railways, canals, and industrial clusters

An advanced shipyard could not sustain itself. Japan also had to contend with earthquake risk and competition between army and navy spending while moving guns, bearings, steel, and armor among industrial centers. Railways and canals could connect factories directly to yards and reduce dependence on coastal shipping. Britain partly concealed this problem because its major shipbuilding districts sat inside concentrated industrial complexes able to provide most necessities locally. The apparent safety of sea transport also reflected a pre-submarine setting in which coastal shipping seemed less vulnerable. Between the world wars, Britain's Big Four railway companies recapitalized parts of the network and promoted direct factory-to-yard links. The example shows how transport policy could sustain naval production.