Emergency ascent in case of failure or power out


This has been discussed before and - i guess - been deemed impractical.
The Trieste had iron shot ballast held in place by electromagnets. In case of problems or loss of power, the ballast was dumped and the thing ascended.(Now that’s genius, right?) One could imagine a sacrificial ballast slug which is dumped in case of systems failure. Just an idea …


I looked at this issue but decided not to work forward on it after looking at the environment in which I might operate the unit.
Considering that the ROV is tethered, there is likely an entanglement potential. This being the case, would an emergency ascent of the ROV exacerbate an already troublesome situation. When operating in a cave environment the auto ascent feature may also create problems and would likely not facilitate easy recovery of the ROV. Perhaps in the open ocean environment it would be beneficial to have such a system, where the ROV (and tether) could ascend to the surface unobstructed.

I have opted to equip the ROV with a reinforced (1/4in poly rope) to help with retrieval. Additionally, I am a certified diver and I tend to operate in environments where I could (if absolutely necessary) retrieve the unit by diving after it.

Just some considerations… :smile:



The above is so true, I rest my case :smile:


Ron - I agree with some of the things you say but diving after it. How would you recover it at 300 ft? Are you a tech diver?

What about a backup power supply?


I guess the only way would be to send down another ROV with a grabber and some buoyancy control device to help lift the weight. Has anyone experimented with CO2 capsules like you get in lifejackets, but controlled through a valve, perhaps?