The Costa Concordia cruise ship hit a rock near the coast of Italy, ripping a hole in its hull and causing it to list. Due to its high center of gravity, the ship had difficulty returning to an upright position as water filled the damaged side of the hull. Though the ship had taken on water and was listing severely, the captain initially decided to continue sailing. However, during a sharp turn attempted later, the change in tilt angle exposed the hole to more water intake, causing the ship to capsize. It ultimately sank after capsizing so close to shore that it ran aground.

2. The Sinking of the Costa Concordia
Click on the video link to learn more about the sinking of the Costa Concordia.
https://www.youtube.com/watch?v=MxPJCNv_U84

3. The following reconstruction of the
sinking of the Costa Concordia is
based on news reports, videos, and
photographic evidence. We apply
logical reasoning to come up with
the scenario.

4. The Sinking of the Costa Concordia
Because the ship was approaching too close to land, it hit a rock jutting out of the
water, almost like a car riding over a bump on one side of the car.

5. The Sinking of the Costa Concordia
The rock would have caused the ship to list clockwise, as shown. Because of its
high center of gravity, the ship would have listed at a greater angle than a ship with
a lower center of gravity.

6. The Sinking of the Costa Concordia
Think of a hemispherical piece of styrofoam with a short straw sticking out. Tilting it
sideways will have the hemisphere return to its equilibrium position fairly quickly.

7. The Sinking of the Costa Concordia
Try the same thing with a longer straw, which has a much higher center of gravity.
In this case, the straw will bend more and return to equilibrium much slower, due to
the higher center of gravity.

8. The Sinking of the Costa Concordia
A cruise ship has a very high center of gravity, so when it lists, it returns to its
equilibrium position slowly.

9. The Sinking of the Costa Concordia
The collision with the rock created a giant hole in the hull of the ship. And water
immediately rushed into the hull.
Hole in
the hull.

10. The Sinking of the Costa Concordia
Because of the ship’s tilt, the water rushing into the hull collects on the opposite
side, away from the hole.
Water fills
one side of
the hull.

11. The Sinking of the Costa Concordia
The slowness of returning to an equilibrium while water is rushing into the hull
actually keeps the ship listing. From this point on the ship will continue listing and
will not return to its equilibrium position.

12. The Sinking of the Costa Concordia
It’s possible that the ship reached a new equilibrium point. If so, the ship was listing
at such an angle that the hole in the hull was above water, with little additional water
was coming in.
20°
At this angle
no additional
water comes in

13. The Sinking of the Costa Concordia
The ship should probably have been evacuated immediately, but the captain
decided to continue sailing, until it was clear the ship could go no further. At this
point a hard turn to the port on the island is attempted.

14. The Sinking of the Costa Concordia
The sharp turn would have reduced the angle of the ship’s listing, due to centripetal
acceleration. But reducing the angle of title would have exposed the hole in the hull
to more water and the ship would have taken on more water.

15. The Sinking of the Costa Concordia
With more water coming into the hull, while the ship is turning, the Costa Concordia
capsized.

16. The Sinking of the Costa Concordia
Because the ship was so close to land, in capsizing it hit bottom and remained in
the position it now finds itself in.

17. The Sinking of the Costa Concordia
• In summary, this chain of events led to the
sinking of the Costa Concordia:
– The ship hits a rock jutting out of the
water.
– The rock causes the ship to list and rips
a hole in the hull.
– The ship takes on water on one side,
causing the ship to stay tilted.
– The ship continues sailing but then a
sharp turn is attempted.
– This sharp turn changes the angle of
tilt of the ship, exposing the hole in
the hull to more water.
– After taking in more water, the ship
capsizes and runs aground.