Ocean engineering expert offers perspective on the missing Titanic submersible
The search continues for a tiny submersible lost in the North Atlantic. The 22-foot vessel, called Titan, had set out with five men on board to explore the wreckage of the Titanic when contact was lost.
Stefano Brizzolara, codirector of the Virginia Tech Center for Marine Autonomy and Robotics, shared insights on the challenges facing the submersible and the searchers.
Q: Why does the Titanic’s wreckage pose a challenge to sonar detection?
“The structural failure of Titanic and its sinkage left lots of parts and debris around the two halves of the vessel, which makes it very difficult to detect a small submarine like the Titan. Another challenge is the location of the sonar scan area: modern sides scan sonars offer very good resolution, but they need to be operated in close proximity to the bottom (which is at a depth of about 4,000 meters) to ensure a good resolution. An ideal vehicle for this search operation would be similar to a self-propelled autonomous underwater vehicle that our lab designed, capable of operating at that depth and making a high-resolution scan of the ocean bottom.”
Q: Why is communication with the submarine underwater challenging?
“Electromagnetic waves decay in a matter of meters in sea water, so communication underwater is based on acoustic waves. The propagation of acoustic waves in water is highly affected by temperature, salinity, and density in stratified bodies of sea water, especially at distances over 4km. The sudden change of density and temperature of sea water act as a lens that refracts and may even effectively reflect acoustic waves, making it practically impossible for them to reach the surface. In fact, navy submarines use this feature to hide themselves from surface ship sonars.”
Q: What design issues could cause trouble for a submersible like Titan?
“The thruster configuration of Titan was not apparently designed with redundancy in mind, so if one or more thruster failed, the other ones may not be sufficient to maneuver and bring the vehicle back to the surface. Additionally, the integrated joystick type of control of the thrusters may not be able to cope with a failure of one or more thrusters. Also, even with all thrusters working, the available thrust for the vehicle to maneuver and unblock itself from deadlock onto a structure protruding from the Titanic relic, or from grounding on a sea bottom structure, may not be enough, depending on the type of entanglement.”
Q: What other risk factors exist?
“Regarding oxygen reserves, Titan does not have any system to reform carbon dioxide into oxygen like naval submarines have, unfortunately. Another problem is temperature. At those depths the water temperature is close to zero Celsius and the temperature inside the vehicle can drop pretty quickly, especially in case of some power system failure.”
About Brizzolara
Stefano Brizzolara is a professor and Crofton Faculty Fellow for Virginia Tech’s Kevin T. Crofton Department of Aerospace and Ocean Engineering and cofounder of the university’s Center for Marine Autonomy and Robotics. Read more about him here.
Schedule an interview
To schedule an interview, contact Mike Allen in the media relations office at mike.allen@vt.edu or 540.400.1700.