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My favorite part of the article is the mention of the submarine hitting an uncharted sea mount. I rarely think about the fact that they can't just leave sonar

My favorite part of the article is the mention of the submarine hitting an uncharted sea mount. I rarely think about the fact that they can't just leave sonar on at all times to be aware of their surroundings and often rely on known mapping data.

whatever1 3y ago
But why submarines do not have a tethered drone traveling I don’t know, 1 mile ahead of them and hit such obstacles?
- asdfman123 3y ago
  Cost and complexity is probably one part of it.But more importantly, I imagine having a drone ahead of them would generate noise, thus decreasing stealth. It's probably one of those things that shouldn't happen if you're doing everything else the "right" way.
- Thrymr 3y ago
  It would not be trivial to design an separate underwater vehicle that could travel ahead of a submarine at flank speed (>30 knots), let alone do so quietly.
edgyquant 3y ago
Why not exactly? Due to stealth or some other reason?
- geoduck14 3y ago
  Stealth is a big component. Also, Sonar is known to impact marine life I believe there are Sonar bouys that are toed behind ships to detect submarines. These could be used, and I would guess that these are used to map the sea floor, but the sea is so flipping big that there are still unmapped areas. But I'm not an expert and would defer to an actual expert (or ChatGPT)
  - jedc 3y ago
    Active sonar (where a device sends a pulse of energy & listens to replies) can impact marine life. Passive sonar (where you just listen to acoustic energy in the water) is used by submarines and surface ships to find submarines. With both on-board and towed sonar. Submarines don't have any sonar designed to map the sea floor, though there are tools to identify the depth below the keel at any given time. Creating proper maps of the sea floor are done by much more specialized equipment/systems/processes. https://en.wikipedia.org/wiki/National_Geospatial-Intelligence_Agency https://en.wikipedia.org/wiki/National_Geospatial-Intelligen...
jedc 3y ago
(former US submariner here) Also commented downthread, but sonar IS always on at all times. https://news.ycombinator.com/item?id=35780124 https://news.ycombinator.com/item?id=35780124 Honestly, I'm extraordinarily surprised that the USS San Francisco didn't sink killing everyone onboard. Have you seen the photos? https://en.wikipedia.org/wiki/USS_San_Francisco_(SSN-711)#/media/File:US_Navy_050127-N-4658L-030_Submarine_USS_San_Francisco_in_dry_dock_to_assess_damage_Guam_Jan_8_2005.jpg https://en.wikipedia.org/wiki/USS_San_Francisco_(SSN-711)#/m... The only reason that the submarine was able to get to the surface and stay there after this was because the damage was just on the port (left) side. Even with that luck, they were only able to stay on the surface because a piece of equipment was able to stay running for several times longer than it was designed to do. You can read more about it in various places (like here: https://nationalinterest.org/blog/reboot/what-happens-when-submarine-hits-underwater-mountain-184924 https://nationalinterest.org/blog/reboot/what-happens-when-s... ) but imagine being at work and suddenly getting thrown toward a wall at 20++mph. Damages and injuries everywhere, and its a miracle only one person died.
- officeplant 3y ago
  >but sonar IS always on at all times Yeah completely forgot there is both active and passive sonar.

whatever1 3y ago

But why submarines do not have a tethered drone traveling I don’t know, 1 mile ahead of them and hit such obstacles?

asdfman123 3y ago
Cost and complexity is probably one part of it.But more importantly, I imagine having a drone ahead of them would generate noise, thus decreasing stealth. It's probably one of those things that shouldn't happen if you're doing everything else the "right" way.
Thrymr 3y ago
It would not be trivial to design an separate underwater vehicle that could travel ahead of a submarine at flank speed (>30 knots), let alone do so quietly.

edgyquant 3y ago

Why not exactly? Due to stealth or some other reason?

geoduck14 3y ago
Stealth is a big component. Also, Sonar is known to impact marine life I believe there are Sonar bouys that are toed behind ships to detect submarines. These could be used, and I would guess that these are used to map the sea floor, but the sea is so flipping big that there are still unmapped areas. But I'm not an expert and would defer to an actual expert (or ChatGPT)
- jedc 3y ago
  Active sonar (where a device sends a pulse of energy & listens to replies) can impact marine life. Passive sonar (where you just listen to acoustic energy in the water) is used by submarines and surface ships to find submarines. With both on-board and towed sonar. Submarines don't have any sonar designed to map the sea floor, though there are tools to identify the depth below the keel at any given time. Creating proper maps of the sea floor are done by much more specialized equipment/systems/processes. https://en.wikipedia.org/wiki/National_Geospatial-Intelligence_Agency https://en.wikipedia.org/wiki/National_Geospatial-Intelligen...

jedc 3y ago

(former US submariner here) Also commented downthread, but sonar IS always on at all times. https://news.ycombinator.com/item?id=35780124 https://news.ycombinator.com/item?id=35780124 Honestly, I'm extraordinarily surprised that the USS San Francisco didn't sink killing everyone onboard. Have you seen the photos? https://en.wikipedia.org/wiki/USS_San_Francisco_(SSN-711)#/media/File:US_Navy_050127-N-4658L-030_Submarine_USS_San_Francisco_in_dry_dock_to_assess_damage_Guam_Jan_8_2005.jpg https://en.wikipedia.org/wiki/USS_San_Francisco_(SSN-711)#/m... The only reason that the submarine was able to get to the surface and stay there after this was because the damage was just on the port (left) side. Even with that luck, they were only able to stay on the surface because a piece of equipment was able to stay running for several times longer than it was designed to do. You can read more about it in various places (like here: https://nationalinterest.org/blog/reboot/what-happens-when-submarine-hits-underwater-mountain-184924 https://nationalinterest.org/blog/reboot/what-happens-when-s... ) but imagine being at work and suddenly getting thrown toward a wall at 20++mph. Damages and injuries everywhere, and its a miracle only one person died.

officeplant 3y ago
>but sonar IS always on at all times Yeah completely forgot there is both active and passive sonar.