How Did the Vikings Make Wooden Ships Waterproof?
The success of the Vikings was due to their mighty longships, but how did they make them waterproof?
About 1,000 years ago, the Vikings roamed most of the Old World thanks to their unrivalled ability to build seaworthy ships - and even made it to America. Their most common method of building the efficient ships is known as clinker building and dates back to the Iron Age.
Clinker building requires that the boat is built like a shell of planks, that overlap and hence seal the hull. Shipbuilders used an axe to cut out the planks, planed them, and boiled the planks in long cooking vessels. Subsequently, the planks were bent to suit their positions on the ship hull. By means of wooden or iron nails, the planks were fastened to frames, which functioned as the ship’s ribs.
To make the ship waterproof, the Vikings placed animal hair dipped in tar between all the planks. In other cases, they used moss. This had to be done yearly.