Modern Ships Wooden ships patrolled

Modern Ships
Wooden ships patrolled the oceans on expeditions up
until the late 18th century when ship builders began
to experiment with iron. The British, Portuguese,
Dutch and Spanish navies introduced cannons on
their ships. But the weight of these increased stress
on the wooden beams. So iron was used to reinforce a
ship’s internal frame. By the 19th century, the fourth
phase of ship design occurred. Iron (and later steel)
replaced wood as the preferred material for constructing ships. To prevent sinking,
especially during maritime battles, ship designers built watertight bulkhead
compartments. These were separate boxlike sections made of iron. If a ship had a
hole in it, water would only fill up the one bulkhead.