Why didn’t the wood rot or eventually absorb water and allow water to enter the boat?
In: 9
The same way you make a barrell that holds wine. When wood gets wet it expands, so when you build a ship together with all the seams already tight, when the wood gets wet, it has no where to expand to except it’s neighboring piece of wood. that creates a dam effect. once all the joints are sealed, it will be waterproof.
A few reasons.
First, wood is not the only product that comes from trees. Pines and evergreens also produce waterproofing agents like tar, pitch and turpentine. These are excellent at acting as water-repellent glue. When you pound fibres such as those from coconut husks or shredded cedar bark into the gaps between wooden planks and then add this, it’s a very strong seal that takes a tremendous amount of stress to break.
Second, wood is not really absorbent of water until it’s been exposed to it for a very long time, or bugs or fungi get at it. It takes a while for properly dried wood to become “waterlogged” and heavier than the surrounding water so that it sinks. So if you ‘season’ your wood by air-drying it prior to using it to form your vessel, it’s naturally waterproof for some time.
Third, there’s maintenance. Got a timber that looks like it’s starting to rot? Replace it. If below the water line and holding the water out, beach your craft so it’s not going to let in water while you tear it out.
Later on in marine history, there’s paint, which is excellent at protecting wood from direct exposure to water until it eventually flakes off.
Yes, the wood would eventually rot and also become infested with water-bugs that would eat it and ruin the boat.
This is why boats are historically a *ton of work* to keep constantly repaired and functional.
As u/lekoli_at_work points out, yes, wood does swell when it’s wet, helping seal the leaky spots, but they also coating the wood in metric fucktons of oil, which repeals water.
Think of any old timey movie you’ve ever seen from that era, pirates or pilgrams, or whatever. Are the sailors just sitting around on the boat relaxing? No! They are constantly doing stuff like “Swabbing the decks” and working on shit, they weren’t doing that because sailors are neat freaks. They are removing as much water, dumping on oil, and repairing as much as they as quickly as they can. This is exactly why the sailors were always so young and beaten down, it was a ton of work.
Wood rots in oxygen, so submerged wood will not rot — as evidence of this, we find sunken ships from thousands of years ago that remain intact. There were some areas that were vulnerable, and ships would require periodic repairs to replace damaged wood.
In terms of waterproofing, there are a variety of materials that were used over the years, with pine tar and oils being common options.
You can impregnate wood with wax or oil or other chemicals. And ships are not just cheap wood, the wood for ships is high quality wood that is processed on many different ways.