In previous posts, we’ve been looking at possible designs for Blackbeard’s Queen Anne’s Revenge (QAR), at how Disney’s fanciful design probably didn’t work, and had a discussion how ships were measured in the Golden Age of Pirates.
Something else came out of looking at Disney’s QAR – a question about freeboard.
Here’s a cool test: throw a baseball bat into your bathtub. Oh, uh, fill the tub with water first. See how, even though the bat is made out of wood, she sits low in the water like a submarine. You could blow wind at that thing all day long and have no effect on how it moves in the water. Go ahead and try it. We’ll wait… Now, splash some waves around her. They wash right over – there is no dry place to stand.
Now take an empty shoebox and drop it into the tub so that it floats like a boat. Give her a blow, and off she goes, skittering across the water like a dry leaf. The slightest breeze tells the shoebox where to go. Give her some waves – even big ones, and she stays dry as a pirate’s bones.
Was you a sea cap’n in Blackbeard’s day, the ship you’d be looking for would have properties of both the shoebox and the bat. You’d want her to sit low in the water, where wind and wave would have no effect. But you’d want to sit high above the water, too, so that you could fit cargo, crew, and guns up where it’s dry.
The shapes of ships in the sailing days, then, were just that mix: cut the baseball bat in half width-wise, and you get a nice, semi-circular cylinder. Cut the shoebox in half height-wise, and you get a nice, dry box that sits upon the seas. Now, scale them so that they are the same width and length, and connect one to the other, and there, you have a nice, dry hull that has good seakeeping capabilities.
The challenge lay in the mix between the above-water box and the below-water bat: too low and she wallowed like a pig in mud, but too high and the wind pushed her sideways. It’s a problem of too much freeboard – the sides of the ship actually act like a sail, making it extremely difficult to steer on a windy day. Worse, too much freeboard can be deadly, as the Swedish found out with the Vasa in 1628 – the richest, most powerful warship in the world in her day. The Vasa took a sudden random breeze against her high, high sides, and over she went, upside down and sinking in just ten minutes with all hands.
That brings us back to Disney’s Queen Anne’s Revenge, and that enormous, enormous stern castle. It makes for great film making inside, with that cool window and all that headroom. But it would make for dreadful and dangerous sailing. Her stern would sit low in the water, pushing her bow up like a motor boat. And any wind other than dead over the stern would push sideways against that beautiful stern castle, making her sail sideways. Worst of all, she has a very shallow draft, the baseball bat part of the hull, which means she’d roll like a beach ball.
In our search for the true Queen Anne’s Revenge, we have to remember that Concord, the original ship, must have been a well-designed merchant ship, drafted with a steady and wise hand.
The search continues!