You would never make it to the bottom of the ocean without any equipment, because you would run out of oxygen, and your body would be shut down by the pressure underwater. So if you want any chance of surviving this journey, you’ll need some sort of capsule to bring you safely to the bottom.
But what would this capsule look like? Would you be able to make it back to the surface? What features would it need to survive the extreme conditions?
Number one: The Ability to Withstand Pressure
How will you know what your capsule will need to bring you to the bottom of the Mariana Trench safely? Let’s take a look at two capsules that have already made the journey: the DSV Limiting Factor and the DeepSea Challenger.
About 70% of the Deep Sea Challenger’s volume is made up of something called syntactic foam. Syntactic foam is the only floatation material that can withstand the incredible pressures in the Mariana Trench.
It’s made up of millions of hollow glass microspheres suspended in a paste-like substance called an epoxy resin. Not only does this material have the strength to withstand the constant pressure, it also has the low density required to keep the capsule buoyant.
If you didn’t have this sort of protection, you’d fall victim to the high pressure levels pretty quickly. The pressure from the water would push in on your body, causing any space that’s filled with air to collapse, including your lungs. At the same time, the pressure from the water would push water into your mouth, filling your lungs back up again with water instead of air.
Number two: The Ability to Return to the Surface
It’s one thing to be able to make it down to the bottom of the Mariana Trench, but it’s even more important to be able to make it back up to sea level. The DeepSea Challenger has 450 kg (1,000lbs) steel weights attached to either side of it to ensure it will sink to the bottom.
And then, whenever you’re ready to return to the surface, you can simply release the weights. But what if you encounter some sort of emergency?
Well, If there is a power failure, the weights will drop automatically. And if you have a support team at the surface, they can command the weights to drop as well. There is also a special wire that attaches the weights to the sub that will corrode after 11-13 hours in seawater, just in case.
Number Three: An Oxygen Supply
Your submarine capsule is a sealed container that has a limited supply of air. If you want to keep that air breathable, there are two main things that need to happen.
For one thing, the oxygen has to be replenished as you use it. If the percentage of oxygen in the air falls too low, then you’re going to suffocate. Also, the carbon dioxide needs to be removed from the air. If the concentration of carbon dioxide rises, it will become toxic.
The DSV Limiting Factor’s air supply consists of a rack of oxygen cylinders, and a system that operates like a small planet. The carbon dioxide you exhale into your capsule is removed by devices called carbon scrubbers. They clean the air, allowing you to breathe it again.
Basically, you would be breathing the same air over and over again. This gives you an oxygen supply that will last for an impressive 16 hours, along with an emergency backup that will last an additional 96 hours.
Number Four: Long Battery Life.
When you make your journey down to the depths of the ocean, you’re going to be relying entirely on battery power, so make sure you’ve got a lot of it. The DeepSea Challenger has about 70 bread loaf-sized battery packs inside oil-filled plastic boxes mounted into the sub’s sides.
The batteries are spaced just far enough apart that they won’t be disrupted when the foam structure that they sit in shrinks by about 1 percent under the ocean’s pressure. Having a lot of batteries isn’t just important for the obvious stuff, like controlling the ship. There are also dedicated battery systems for search and rescue purposes.
For example, one battery system is completely dedicated to powering LED lights that can assist a recovery team trying to find the capsule when it returns to the surface. So there you have it. Surviving a trip down to the Mariana Trench is pretty easy, as long as you can afford a fancy submarine. Some companies have even started bringing tourists down there.
- “CO2 Scrubber” 2020. Greenliving. lovetoknow.com.
- “Q & A: If You’re At The Bottom Of The Ocean Or In Space… | Department Of Physics | University Of Illinois At Urbana-Champaign”. 2020. van.physics.illinois.edu.
- “What Is Syntactic Foam? – Engineered Syntactic Systems”. Engineered Syntactic Systems.
- “How Deep Underwater Can A Human Go?”. 2014. Popular Mechanics.
- “The Mariana Trench: Earth’s Deepest Place”. National Geographic Society.
- “What is Syntactic Foam?“. 2018. Jayhawk.
- “Mariana Trench: The Deepest Depths”. livescience.com.