Why do Ships Sink?

Only Mike Brady could keep your attention for 15 minutes by explaining how a ship will sink when flooded with water.

I thought it was because, all of a sudden boats realise that they’re heavier than water? It’s like when aeroplanes crash because they realise they’re not birds.

One of my favourite interview moments I ever heard was during an Australian press event for Clive Palmer's (still never to be) Titanic 2... As one of the engineers was explaining how the new replica would be much safer than the original, one of the reporters tried to get a soundbite moment by asking him "so would you say it's unsinkable?" Quick as a whip he replied, "oh no, I would never say that. For the record: if she can float, she can absolutely sink." Ship building 101 right there. The man wasn't about to be caught out by that old trick.

Mike. I love you my friend. However, you forgot to mention loose lips

Polynesian explorers used to intentionally flood their wooden canoes in rough weather to stop from bouncing around in the waves. You'd think they would sink, but the wood is naturally buoyant. :hand-orange-covering-eyes:

Usually when an unplanned field modification results in a larger-than-standard cold water intake to be installed somewhere on the hull.

Just a quick story. I served in the USN, and was assigned aboard the aircraft carrier USS Independence. I went aboard while the ship was in dry dock. I’ll never forget the first time I saw the ship sitting in that dock on blocks and was overwhelmed at its size and remarked out loud “ how on earth does it float?!” First time at sea was scary and exciting for me. And after a while, we all became convinced it was unsinkable, short of an atomic blast: or so we reasoned. About a year latter we were caught in a massive storm in the Mediterranean Sea for about 3 days and night, that quite terrible. Suffice it to say, all hatches were shut and no one was allowed to go up on the flight deck or open any outside hatches. With 40 to 60 ft swells, we 🎉had water over the bow . I know because I went up in the island structure and managed to see out over the flight deck. Up until that time, we’d seen many rough seas and we thought little of it. But this big typhoon changed it all for me and about 3,000 of my shipmates. The power of a storm at sea is an awesome and scary thing to endure when all you can do is ride it out. During those 3 days and night, I think everyone onboard spent the majority of their of their time praying, because you certainly couldn’t sleep through it. More to tell about that experience, but I’m afraid people would think I was exaggerating.

IJN Yamato and HMS Barham were on the way down anyway when their magazines exploded, it hastened the end but not by much in either case. With USS Arizona and HMS Hood (also with the British battlecruisers at the Battle of Jutland) the magazine explosions were the direct cause of the sinkings.

I believe in the UK North Sea during oil and gas exploration a fishing boat that had been mysteriously lost some decades earlier was found on the seabed in the middle of what geologists call a pock-mark. These are the marks left behind when gas escapes from beneath the seafloor. What is thought to have happened to this unfortunate trawler was that as it sailed along minding its business, a huge bubble of methane gas burst out of the sea bottom having escaped from geologic strata below and the boat found itself suddenly surrounded by a mixture of water and gas which does not have the same buoyancy as seawater. It would therefore have almost instantly sunk. All on board were lost and there was no distress call.

The Swedish Warship Vasa comes to mind. It sank in calm seas as it was simply too top heavy.

It’s our friend Mike Brady, from Oceanliner designs

A tiny tidbit regarding Yamato sinking: In October 1944 the sister ship Musashi was also attacked by the US aircraft in the Battle of the Sibuyan Sea. The ship took approximately 19 torpedoes and 17 bombs and yet sank only hours after the battle. That's why the US torpedo bombers were ordered during the attack on Yamato to aim exlusively at one side of the ship in order to capsize it - that's why Yamato went down capsizing and after receiving many, but not as many hits as Musashi.

Interesting video, the physics behind ships is already mind boggling!

Because of water! Put the ship on land and it wont sink!

“Because water gets in them”, the witty ones will say. Funny, I was typing almost that exact phrase.

This does raise another, related question. The rules concerning safety of life at sea have been continually updated after every major disaster in history. But in the last few decades, we have seen a massive increase in how many people are on a given ship without a resulting tragedy to give impetus to updating those rules. There were ~3,300 people on Titanic, but the newest cruise ships can have more than 10,000 people on board. How have the relevant authorities adjusted their rules and plans to account for the possibility of having to rescue that many people at once? Or are they still depending on "any ship nearby help out"?

Scuttling. That's another way water gets in on the wrong side of the hull and ruins that buoyant force thingy. Opening the seacocks, valves that are for allowing water in and out of the ballast tanks or for allowing water inside clean the bilge, etc., to intentionally sink the ship, perhaps to prevent the vessel from falling into the wrong hands. Perhaps one of the greatest examples of this is the scuttling of 50 German warships at Scapa Flow in November 1918 by their crews under order from Admiral Ludwig von Reuter to prevent the British from boarding and capturing them.

According to Amazon's Rings of Power, things sink because they are drawn to darkness but other things float because they are drawn to light. I'm afraid I didn't make it past that line which was about three minutes into the first episode, so I'm not sure if they went into the thing in anymore depth (see what I did there?!). However, THESE videos are great!

This is such a good overview of not just Titanic, but several famous sinkings, that it could be used as THE introductory video for the whole channel.

This channel is so relaxing and helps me go to sleep. I guess it’s bad that sinking skip information helps me to sleep.