How an early marine-engine breakthrough could spread ashore

The early-boiler scenario extends beyond warships to railways and industrial efficiency. Marine and locomotive machinery differ, but the underlying capacity to manufacture reliable high-pressure equipment could transfer between them. Faster and larger merchant ships would give foreign customers more reason to order from British yards. In the American Civil War scenario, southern buyers might import British ships or machinery instead of investing as much in local production. Northern shipbuilding has a larger market that could sustain domestic investment. These effects depend on the assumed British technological lead.