Steam Box Art

If you’ve ever examined the complex, curvy shapes of the planks that make up a wooden boat’s hull, you might have wondered, “How do they get straight pieces of wood to bend that way?” Steam is part of the answer, brute force is the other.

By Soundings Editors

June 11, 2018

Unlike fiberglass boats, which get their shapes from a highly polished mold, wooden boats rely on hundreds of unique, handcrafted frames to get their curvaceous good looks. Much like a skeleton, a wooden boat’s internal frames give the boat its shape and structural integrity.

Cutting and fitting these frames is easy enough — generally speaking — but fabricating and installing the planks that cover them can be challenging, especially in larger vessels. To get the job done, shipwrights first measure and then cut the planks to size using saws, chisels, hand planes, adzes and axes — or whatever they can get their hands on that works.

Though the planks are shaped with extreme accuracy, they are too dry and stiff to conform to the shape of the hull. To make it more pliable, shipwrights load the plank into a steam box to soften it up. After a couple of hours, the plank can be removed and then coaxed into place using sledgehammers, wedges, clamps and screws. This video shows the process.