Hasta La Ideas

It’s the cargo you can’t see that’s the problem

Ships need what’s called ballast, a certain amount of weight in their holds to provide stability. In a fully laden cargo ship, the cargo itself can serve as the ballast; but it can’t make its return journey empty, or something like what you see in the photo below would happen:

As we saw in an earlier post, this is why many New England cities that served as early trade ports with Europe are paved with cobblestones; ships traveling from the Old World were loaded up with the stuff, to be dumped on American shores to make room for New World goods. Enterprising city officials turned the otherwise uselss rocks into roads.

Over a century ago, some ingenious, unknown ship designer(s) came up with the idea of using seawater itself as the ballast. On its surface this is a brilliant idea. Valves allow seawater to fill compartments in the bottom of the ship as it is unloaded with cargo, enabling the ship to maintain perfect equilibrium. And when the ship gets into its next port and needs to load up, the seawater is simply evacuated.

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