Why Cruise Ships Are So Slow

Why Cruise Ships Are So Slow

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So you’re having a race between a plane,
a car, and a ship. Now whoever decides to place their big bet
on the ship would have a bad day. Loser! And this is despite the fact that ships have
the most powerful engines! But why? We’re going to find out right now. Ships come in all shapes and sizes. From motorized dinghies to yachts; from glorious
looking white cruise ships to grim and bulky container ships and tankers. But they all share one quality: their engines
seem excessively powerful, yet they still can’t seem to output the speed you would’ve
expected from this kind of power. The reality is the exact opposite of the expectations:
a big liner can cross the Atlantic Ocean in a week, but a cargo ship would have to spend
more than two weeks to do the same thing. For a plane to go from an airport in Western
Europe to New York, for example, it would take only 8 hours. Some people might ask why we even use ships
if planes are so much faster. Well, here’s the catch: you won’t be able
to carry thousands of tons of weight by plane. The same goes for the number of passengers
– some ships can carry more than 5,000 passengers in one go! Try to fit that crowd in an airliner. Hey we can duct tape ‘em to the wings! As a further illustration, let’s take a
look at the supermassive ore carriers like Valemax – she’s a 1,188 ft long monstrosity
that can carry 400,000 tons of metal ore deadweight. That’s more than the weight of the entire
Empire State Building! Yet the ship will only go 17 mph, or 15 knots
as mariners would call it. That’s not even as fast as the running speed
of an Olympic track athlete. So in general, ships are going slow just because
they don’t need to go faster; their aim is set somewhere else completely. They sacrifice speed for better carrying capacity. Cars and planes may be faster, but even with
half of a cruise or cargo ship’s regular burden, cars wouldn’t even move, and the
plane wouldn’t be able to leave the ground. The engines of big ships are huge powerhouses
taking up entire rooms and swallowing tons of fuel each day like it’s a snack. ‘Emma Mærsk’ – the biggest cargo ship
in the world, capable of carrying up to 12,000 20ft metal containers, has an engine that
weighs 2,300 tons. When installed in the lower part of the ship,
it takes a three-story construction built around it for the crew to be able to provide
maintenance. It’s capable of producing more than 100,000
horsepower output of engine power. Transferred to an energy value, that would
be more than enough to power up a small city. “Uh, engine room, yeah we got some bad news. We need to step it up down there, the captain
wants to go water skiing.” This example may sound extreme, but it shows
just how much more powerful big ships are compared to cars or even planes. In contrast, ships have much more trouble
moving at all. When a plane flies, it needs to maintain enough
speed to stay up in the air, and it needs to avoid clouds when possible. You’ve probably experienced this nerve-racking
moment for yourself: when a plane goes through clouds it shakes quite a bit. This is because clouds are denser than air,
causing friction with the plane when it collides with the water vapor the clouds are made of. Unfortunately, ships have no choice but to
deal with the dense environment that often almost fully covers the ship’s hull. Water produces huge friction, slowing down
any movement significantly. Even something as fast as a bullet would slow
down and finally stop after just 100ft through the water. This is why every ship needs more power to
move at all. But brute force isn’t the only way ships
deal with the friction problem. Another big deal is the necessity to minimize
the area where the ship comes in direct contact with the water. And here come two big problems. It probably already occurred to you that not
all ships are huge liners, and some other ships can actually be quite fast. Yes, and those fast vessels are smaller. They go faster because they weigh less and
can glide right on the surface of the water using the thrust of their engines. Another trick smaller boats use is splitting
the hull into two parts. These boats and yachts are called catamarans. Their buoyancy isn’t as good as that of
a single-hull vessel, but they greatly reduce the need to touch the water with their smart
design. Getting back to the big stuff. A large ship is naturally submerged in the
water with a part of its hull up to the waterline. But this line shows only the predicted level
of water for the ship alone. If the ship is loaded with cargo, it’ll
be submerged deeper than that. And this means that it not only needs more
power to move its weight, but the water will make it even slower because there’ll be
more friction in play. But dealing with water is even trickier than
that. When a ship moves in the water, it displaces
a volume of water equal to the volume of its hull that’s submerged. This displaced water becomes waves that go
to the sides of the ship. These waves further increase the area of contact
with the water and therefore increases the friction. It may not seem like a big deal, but in reality,
it doesn’t only slow the ship down by as much as 40%, but also notably increases the
consumption of fuel. And that’s a big deal for transport companies. Good thing there was an ingenious solution
to this problem. All modern-day ships have a so-called bulbous
bow – the thing that’s submerged in the water right under the nose of the ship. These are exclusively designed for each type
of ship. Depending on the size, carrying capacity,
speed, and shape of the ship, the bulbous bow would also differ in size and shape. A bulbous bow is the first thing the water
meets when a ship is moving. Following its form, the water will try to
make a certain type of waves, but then it will encounter the main hull and also try
to produce waves of another type. When these two waves try to form at the same
time, they simply can’t, because they cancel one another out completely. This is why modern ships don’t produce waves
around them anymore, and their speed is no longer so heavily affected by them. You can see for yourself – the water around
modern big ships is relatively flat. If the shape of a bulbous bow is even slightly
deformed, it won’t be effective at all, and waves will appear once again. But hey, if you want some speed, that doesn’t
mean you have to forget about ships and boats entirely! Even cruise ships these days can be fast. HSC Francisco is one ship just like that. It combines the size of a cruise ship, capable
of carrying 1,000 passengers in luxury, and the design of a catamaran. Each side of the hull is fitted with wave-piercers
to further improve the speed of the ship. And if it wasn’t already enough, it’s
powered by a gas turbine engine that drives two water-jets. These jets shoot powerful streams of water
and propel the ship forward. Each jet stream shoots 6,300 gallons of water
every second and provides enough thrust to speed the ship up to an unbelievable 58 knots,
or 67 mph. For such a huge vessel, this speed is almost
unheard of. And that’s not the fastest you can go on
the water of course. WP-18 Special Forces Interceptor is a boat
you’d expect to see in a sci-fi movie. But it’s real, and it’s literally cutting
edge design is specially developed to cut through waves at the extremely high speed
of 65 knots, or 74 mph. The main purpose of this vessel is, as you
can guess, to intercept ships that are trying to escape. Like, for example, pirates or other criminals. And let’s just say, it’s not even worth
trying to shake this speed demon from your trail. A rush for top speeds was, and always will
be, in people’s minds no matter what. This gave birth to another incredible vessel
– The Mystic Powerboats C5000. A 50ft long catamaran boat that’s so fast,
it needed a cockpit to protect the driver. The max speed achieved in this boat is mind-blowing
250 mph. If you want to go even faster, I have bad
news for you: the sea won’t let you, because it won’t be calm enough. Speeds higher than that would be too dangerous. For a boat that goes this fast, the waves
would be as hard as concrete. Going into one of them would launch the boat
into the air like a trampoline and the next wave would simply crush it. So it seems like about 300 mph is the natural
speed limit of the sea itself. Hey, if you learned something new today, then
give the video a like and share it with a friend! And here are some other cool videos I think
you’ll enjoy. Just click to the left or right, and stay
on the Bright Side of life!

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100 Comments

  1. Well I did learn something new. I thought the thingy in the front was for balancing the boat AND I'm so happy my hubby is not a speed boat driver !! I need him alive 😉 Thanks 👍

  2. 🧑🏻
    👕
    👖

    This is Ben, he has no friends
    One like = one friend

    👈🏻Small Artist here any help would be appreciated

  3. You have been çüršęd until year 2050 😯

    Turn This Blue to Undo

    👇🏽 I’m gifting my next 100 subs! 💫

  4. I enjoy some of this videos but they’re way too long being over 10 minutes and having to watch annoying commercials at the beginning. Reason why I’m forced to watch without actually clicking on the video and having to read the awful captions and slow beginning.

  5. Hi @brightside, i wanna ask you something about your something, please try search Sisi Terang in YouTube search bar.
    Why? Because ‘Sisi Terang’ is an Indonesian version of Bright Side, they have the same video intro as you have, and i still don’t know if that account is officially from Bright Side or not. Here, I’m talking about this account’s name, this account’s rights, and about copyright things.

  6. MSC Gülsün, the world's largest container ship by carrying capacity, set sail on July 8, 2019 from the Port of Tianjin in China to Europe.9 Jul 2019

  7. 3:46, apparently there are some heavy weights and stuff in that rubber ducky. It defies physics, hats don't stay on underwater, the boat would float for a bit, and, yeah none of that makes sense.

  8. Hello small youtuber here, PRESS THE BUTTON!!!

    You are amazing and beautifull and i wish you a piecefull and good life and i hope you get many friends.
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  9. Title: Why cruise ships are so slow.

    Me: They aren’t slow they are fast they just look so slow because they are so big. They also need to go slow because water has very little friction so it takes a while for it stop, especially navigating through a breakwater into a port in the exact place so they customers can get off the boat and have a look around.

  10. Brightside can't even get simple scientific facts right. Planes don't experience turbulance in clouds because they are denser than air. How can clouds be denser than air, if they were they'd just sink, right? What utter rubbish and demonstates a complete lack of even the most basic scientific understanding. If planes do experience turbulance within clouds it's due to the convective updraughts that are causing the clouds to form in the first place.

  11. Slower is cheaper, they are paying by the day, not the mile. Go 10 miles off shore, drive around in circles for 6 days, go back. The idiots would be just as happy.

  12. If you guys aren't sure what is a cruise ship, can you google it b4 you give this title?!
    Here i have done it for you :
    A cruise ship is a passenger ship used for pleasure voyages on which the voyage itself, the ship's amenities, and usually the different destinations (ports of call) along the way each form part of the passengers' experience.

    This clip is not talking about cruise ship at all!
    And you gave a very bad illustration of ship vs airplane.
    (If one plane can't carry so many people, then get more plane to carry!)
    Most of the time, It's not airplane couldn't carry heavy staff, its because airfreight is more expensive then sea-freight. (not to mentioned those extremely big and heavy staff)

    Do your research well because you post. Your millions subscribers don't come easily.
    Don't take us for granted and mislead the public.

  13. Actually you are right cars won’t be able to move but semi trucks will when caring a container when a cargo ship goes down a little bit cause the load it’s called draft

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