Pressure & Plunge: Understanding atmospheric pressure and the Titan Submersible's Fate

Atmospheric pressure, ocean depths and the titan submersible

Hey there! Welcome to another science newsletter.

It was disheartening to hear of the loss of lives in the June 18^th Titan submersible implosion. Today, I will explain the role of atmospheric pressure in relation to this tragic event.

Firstly, let's delve into the concept of atmospheric pressure. Put simply, it is the weight of the air that surrounds us while we sit or stand. This air exerts force on everything it encounters, including our bodies. It's worth noting that this pressure decreases as we ascend in altitude. So, the pressure experienced atop a mountain is considerably lower compared to that in the ocean. The unit for measuring atmospheric pressure is “atmosphere” and it is often abbreviated as “atm”. For the pressure in the ocean, it goes up about 1 atm for every 10 meters of water depth. At a depth of 4,000 meters, the pressure is approximately 380 atm (that’s like 4 bulls standing on every inch of your body).

The titanic wreck that the Titan submersible was going to tour is about 3,800 meters deep – that’s as deep as four times the height of the tallest building in the world (plus another 500 meters). That’s very very deeee..…pp. Now, large ses animals like whales can withstand extreme ocean pressure, but for humans, you can only withstand so much. According to the National Oceanic and Atmospheric Administration, regular scuba divers should not venture beyond a maximum depth of 39.6 meters. It's worth noting that submarines and submersibles are designed to withstand greater atmospheric pressure, but even they have their limitations, especially when it comes to the mind-boggling depths of the ocean.

On another note, there’s been several speculations as to why the titan submersible imploded. I won’t necessarily go into the details of that since it’s not the main purpose of this. However, I will give brief insights from different experts. The first speculation was given by Alfred McLaren – a retired US Navy captain. According to him, he suggests that the Titan submersible failed not because it was made from carbon fiber, but because it was created using three dissimilar materials – carbon fiber, plexiglass, and titanium. His idea is that these materials have distinct molecular structures, and the repeated exposure to the ocean's conditions caused expansion throughout the vessel and its eventual implosion.

A second opinion suggested that the carbon fiber composite structure could not handle the external pressure typical of what is found at ocean depths. These are two of the most prominent speculations as to why the titan submersible imploded. During my research, I also found that titanium submersibles such as the “DSV Limiting Factor” can handle such massive pressure for multiple trips to ocean depths and are less prone to implosion. However, the obvious advantage to using carbon fiber in the Titan is not solely due to its strength, but its strength to weight ratio. It weighs less than titanium. According to this video here, Titanium can withstand up to 3.2 times the pressure it takes to break carbon fiber, but it also weighs 3.2 times as much.

For the purposes of this post, the more relevant question is “how did the titan submersible implode?” This video below simplifies the how. It provides a visual description of what deep sea implosion looks like.

This other video demonstrates the force of atmospheric pressure. It’s a little bit lighthearted but don’t miss the key points.

PS: I want to emphasize that my intention is not to be insensitive to the individuals who lost their lives in this tragic incident. My aim (as always) is to explain the science underlying the tragedy and to help my readers understand the complexities surrounding the event. My heartfelt wishes go out to the families of the departed, may they find healing and solace in this difficult time.

Thanks for reading again and please look forward to my next post.

Image credit: Photo by Mat Brown on Pexels.