A massive category-three storm is bearing down on the high seas, tearing through everything in
its path. The seas roil with huge waves, boats bob up and down on the surface,
and fishermen pray to whatever Gods they know to get them through the voyage safe.
And you’re aboard a giant cruise ship, enjoying a lovely dinner! Maybe afterwards,
you’ll go down to the casino and try your luck.
Yes, cruise ships do seem like strange little oasis in the middle of a sea storm.
But how do these massive boats manage to survive bad weather?
It’s all in the design. When people buy tickets on a cruise ship, they’re not just
buying recreation - they’re buying safety. They want to know that all their needs will be taken
care of for the duration of the cruise, and that includes ensuring that the passengers are safe.
So cruise ships are designed to withstand all sorts of rough conditions - in a way
past ships couldn’t. During the heyday of sea travel, it was fairly common for ships
to be lost at sea. Rough weather, a rogue enemy ship, or a collision with an iceberg
could send the ship to a watery grave - with most or all the passengers going with it.
So what changed?
Obviously, the most famous maritime disaster of all time, the Titanic,
didn’t help. The sinking of the British passenger ship the Lusitania only years
later at the hands of a German torpedo only made it clearer - something needs to change.
These were both hardy ships, ocean liners that were meant for long-distance travel. They could
head from one end of the Atlantic to another in a single go - but that also meant they were
sacrificing maneuverability for strength. If everything went right, they would be reliable,
but if something went awry, there would be very little hope to save the voyage. The Ocean Liner
was a reliable ship - but it was replaced by something better, and today only one Ocean
Liner remains in service. The Queen Mary 2 is more of a relic of an older age of sea travel.
And it’s been replaced with a ship with a much higher rate of survival in case of emergency.
The cruise ship is typically made of lighter material than an ocean liner, and they can be made
to be much bigger. In fact, the Titanic was only 883 feet long, while the largest cruise ship today
- Royal Caribbean’s Wonder of the Seas - is almost 1,200 feet long. While ocean liners focus on being
sturdy, the average cruise ship has some hidden secrets inside that make it much more seaworthy.
So what’s hiding inside these floating cities?
Cruise ships are often…ridiculous. Only a small portion of the ship is below the waterline, and on
top of the ship is a massive multi-level complex often containing thousands of staterooms, dozens
of restaurants, and countless rooms featuring opportunities for recreation. It towers into the
sky, looking very top-heavy. Yet for those people sailing through a storm, their cruise experience
will be largely uninterrupted! Outdoor activities might be cancelled, and the outdoor decks might
be closed to keep people away from the railings during rough waters, but people on the inside
will be able to enjoy their food, activities, and sleep with only some moderate turbulence.
And a lot goes into making sure it stays that way.
The design of the ship actually works in favor of keeping the
ship afloat. The top-heavy nature means the ship is pulling down on the water,
providing a balance to the buoyancy that pushes it upwards. It’s a tricky balance,
and a big part of this is the ship’s center of gravity. While the goal of the design of
a ship is to keep the center of gravity in the middle, that’s not always possible. Ships have a
lot going into them, and the engines and machines that keep it running weigh a lot more. That means
the bottom of the ship will be heavier than the top half, no matter how tall the top half looks.
And it’s all about balancing that.
If a ship is too bottom-heavy, it’s likely to keep sinking. If a ship is too top-heavy,
it’ll be more unstable - which is less dangerous than a ship sinking,
but nothing ruins a cruise faster than it toppling over on its side. So designing a cruise ship is an
extensive process that involves carefully balancing out its weight distribution and
figuring out exactly how much you can build on top of the massive ship. The machinery
being at the bottom keeps the ship’s center of gravity low, ensuring stability in the water.
Stabilizer fins keep the ship from rolling too easily. And the ship is equipped with GPS
devices and other modern navigation systems to ensure it avoids obstacles and remains stable.
But what happens if an obstacle is unavoidable?
Cruise ships will take detours to avoid storms when possible,
but sometimes a storm comes on hard and fast. That’s why the ship relies on far more than its
center of gravity to stay afloat. The design of the bottom of the ship has round edges,
which makes it a lot easier for it to roll on the water and then restore its initial position.
It also has a number of ballast tanks to keep it stable, which is something earlier ships lacked.
These water-filled tanks provide additional stability and distribute the load evenly.
So what is it like surviving a storm on a cruise ship?
Surprisingly, fine! No system is going to be able to completely keep you from feeling the
impact of a raging storm outside, but as long as you stay within the cruise ship,
you’re going to be fine. People have described turbulence, but this is more like mild swaying
than the violent nausea-inducing shaking you might have felt on an airplane or a
much less seaworthy ship. In severe storms, the ship may stop to let the storm pass,
but overall cruise ships can handle harsh weather in a way older ships could not.
And this does more than just save vacations - it saves lives!
Cruise ships are strong, but they’re not invincible. They often have less hull strength
than ocean liners, but better radar to avoid obstacles like icebergs. If they were to hit one,
the odds are that it would rip through the hull and cause serious damage to
the ship. But not all disasters are created equal, and even in the worst-case scenario,
cruise ships are better equipped to survive a disaster than the their cousins.
Let’s look at a tale for two disasters.
Everyone knows the story - the Titanic hit an iceberg and sank, and then Jack and Rose didn’t
try to fit two people on that one board. But how much do we know about what actually went
wrong with the Titanic? When it hit that iceberg, it ripped a hole in the hull of
the ship under the water level, at least three hundred feet long, and that sent freezing cold
water flooding into the base of the ship. As this primarily affected the back of the ship,
it eventually sent it tilting upwards, leading to a massive breakage and making it much harder
to evacuate. This led to a death of over 1,500 people, one of the worst peacetime
maritime disasters of all time. Of course, the biggest culprit in the death rate was the lack
of lifeboats - it was unsinkable, after all. But the design of the Titanic didn’t help.
Now, let’s look at a modern-day equivalent.
The cruise ship industry is considered much safer than the old-timey seafaring industry,
but that didn’t help the residents of the Costa Concordia off Italy’s coast in 2013. Carrying
over four thousand people on board in 2012, it was just kicking off a seven-day cruise
when it struct a rock reef and tore a 16-foot gash into the ship’s hull around 25 feet below
sea level - a very similar blow to the one that took the Titanic down to a watery grave. The ship
began flooding, the engines and generators went offline, and the ship began to sink.
But what happened next was very different.
The ship began leaning heavily to its side, and sank much more slowly. This allowed the crew to
begin a hasty evacuation process, and thanks to a suitable supply of lifeboats, they were able
to evacuate the passengers over a six-hour period. Thirty-four people ultimately died,
but most of the deaths were caused by the ship tilting and passengers falling into the water.
Three people were even rescued from the ship over twenty-four hours after it hit the rock,
as the ship was sinking very slowly thanks to its design
and well-distributed ballast tanks. The Costa Concordia was ultimately scrapped,
and it’s one of the worst maritime disasters of the 21st century, but it was nowhere near
as bad in terms of loss of life as the maritime disasters of the 20th century.
So are cruise ships foolproof?
The answer is…almost! The Costa Concordia was one of the only total losses of a cruise
ship in recent memory. Most of the worst maritime disasters in the 21st century are
of passenger ferries, and while the Costa Concordia was certainly the most expensive,
its loss of life was dwarfed by disasters involving much smaller boats. Cruise ships
are designed to survive intense storms while minimizing its impact on the people inside,
and in the event of a hull-breaching disaster, it has enough safety features
to allow time for a safe evacuation. While we have no evidence of what would happen in
the event of a military attack like the one on the Lusitania - and we hopefully never
will - the modern cruise ship seems designed to give its passengers an easy and safe ride.
Now they only have to worry about a few other things, like viruses spreading on board - be
they norovirus or Covid. Plus, there’s always the risk that the power could go out and leave
you stranded on the open water for several days as the toilets overflow and the food runs out,
like in the infamous “Poop Cruise” on Carnival Sunset. Plus, you never know who you’re going
to be seated next to at dinner - and if that one guy tells you one more anecdote about him
yelling at Starbucks baristas, you may just wish for the ship to sink to the bottom of the ocean.
Want to know more about the most infamous ship disaster of all time? Check out “The
Sinking of the Titanic (Hour by Hour)” or watch this video instead.