But unlike a road surface, the sea itself is continually in motion, changing its shape underneath the hull. The ship travels along the surface, rising and falling with the waves like a truck responding to bumps in the road. One can think of the sea as a bumpy platform. Here, we’ll try to explain the problem in everyday language, and indicate how designers are trying to solve it. You can get some indication of what is involved from or. It’s not easy to predict how a new design will respond to rough seas. But there is always pressure to develop new configurations, or stretch existing ones beyond familiar boundaries. It’s a trade-off between safety, strength and speed, and although there’s no perfect solution, designers have learned where the risks lie, what hull shapes work well, and which are the ones to avoid. We use the term sea-keeping to describe how a ship responds to rough seas. But it wasn’t just a question of speed: clippers could keep up a steady pace in conditions that would defeat other craft. With their slender hulls, tall masts and square sails, the fastest could reach 20 knots and they broke records with every season. Clippers could navigate, for example, between the east and west coast of the American continent via Cape Horn, and race across the Indian Ocean to bring luxury goods from China to Europe. A notable example was the nineteenth century ‘clipper’ sailing ship. In the past, shipwrights relied on experience and craftsmanship to produce vessels capable of surviving in all weathers. Building ships to withstand impacts of this kind poses a challenge to designers, one that distinguishes marine architecture from all other branches of transport engineering. Vessels heave, pitch and roll for hours on end as waves batter the hull, sometimes breaking over the deck and threatening to damage the superstructure or even turn the vessel over. From time to time, a storm will raise waves that are taller than a ship’s mast. There is no shelter in the middle of the ocean. © Harper's Young People M.1115 Seakeeping
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