Mar 29, 2021 - Economy & Business

How we'd float the boat

Ever Given container ship with balloons attached
Illustration: Will Chase/Axios. Satellite photo: CNES/Airbus via AP

Marine architects and salvage experts were flummoxed on how to free the massive Ever Given container ship until today's breakthrough at the Suez Canal. But Axios devised three novel prescriptions for unsticking the big ship:

1. Helium balloons: After all, it worked for that guy in "Up" (and "balloon boy"). The key here is Archimedes' principle — that the upward buoyant force on a body immersed in a fluid is equal to the weight of the displaced fluid (in case you forgot that one from your physics class).

  • WIRED calculated that you would need to displace 50.7 million pounds to raise the ship by one meter, allowing tugboats to pull it free. So we'll use 50.7 million as our magic number. One cubic foot of air weighs 0.0807 pounds (yes, air is a fluid). Then we must subtract the weight of the helium itself (0.0114 pounds/cubic foot), which gives us 0.069 pounds as the weight that one cubic foot of helium can lift.
  • A standard party balloon holds about 0.526 cubic feet of gas, and thus could lift 0.036294 pounds. So to raise our ship one meter we would need 50.7 million pounds divided by 0.036294 pounds of lift per balloon, or 1,396,925,111 helium balloons. Call it 1 billion. That’s roughly half the helium that exists on earth.
Container boat surrounded by pool noodles
Illustration: Will Chase/Axios. Satellite photo: CNES/Airbus via AP

2. Pool noodles: Using our trusty Archimedes principle, a standard 3.5 inch by 55 inch foam noodle can lift about 18.3 pounds. Taking 50.7 million pounds divided by 18.3 pounds of lift per noodle gives us a required 2,770,492 foam noodles. Call it 2 million.

Dolphins surrounding Ever Given container ship
Illustration: Will Chase/Axios. Satellite photo: CNES/Airbus via AP

3. Dolphins: A landmark study in 2008 showed that dolphins can exert between 200-400 pounds of force when swimming. Let's take the middle of that range and assume that our dolphins can all push upwards on our boat with 300 pounds of force (and that they can all work in perfect synchrony, something we might need Aquaman to help with.) Then dividing 50.7 million by 300 pounds of force per dolphin, we'd only need 169,000 dolphins. Sounds like a plan.

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