Elevated CO2 in submarines absolutely impairs performance. One example: there was a guy on my boat who got migraines when CO2 got too high - he was useless. Luckily the fix is simple - just turn on another CO2 scrubber.
There's nothing special about a submarine that makes CO2 somehow different than anywhere else.
I used to row in London on the Thames, and yeah, the tides are nuts. The river rises seven meters in the span of about 3-4 hours. (It takes about 7-8 hours to flow out.)
I got to know Quentin Stafford-Fraser a bit when I was at Cambridge. He's a really down-to-earth guy who was working on all sorts of interesting projects.
Years ago I got to know a startup that effectively reverse-engineered the punchcard-like code necessary to run about half of the massive textile looms used in factories all over the world. Instead of needing to use the ancient systems / software that the loom ran, they built software that could effectively treat the loom as a printer.
It took them a while to find the right business model, but now they partner with huge brands to offer them textile customization AT SCALE, which previously was pretty much unheard of. - https://www.unmade.com/
I remember there was a writeup here of a bottled water brand that created N algorithmically generated unique designs. If you're doing something that scales linearly - inkjet/laser printing, textile manufacturing, 3d printing, etc., why not make each item unique?
> one of the primary reasons subs need to surface , in order to GPS lock
While getting a GPS position is helpful, the primary reason a submarine goes to periscope depth regularly is for communications. The Navy needs to send information to submarines and know that they'll get it and take action within a certain timeframe. That's by far the primary driver.
From layman to former submariner, a very silly question I've always wondered about and that I now have the rare chance to ask someone with some expertise: Do submarines mostly roam about or do they tend to stay relatively quiet/idle? I always imagined submarines constantly moving about but at the same time it feels like a waste of fuel.
Ohio-class submarines (the ones that carry missiles): when they're "on station" they're just tooling around staying as quiet as they can. There's a relevant phrase for them: "Three knots to nowhere"
Los Angeles and Virginia-class submarines are always doing something: doing exercises, transiting from one location to another, etc. And typically multiple things at once. While the boat is transiting from an exercise area to homeport, the team is doing engineering drills, or other kinds of training. Or the forward part of the boat is doing exercises with a carrier battle group while the engineering team is doing engineering drills. (There's ALWAYS engineering drills or maintenance happening.)
Fuel isn't a primary concern: a nuclear reactor is fueled for the life of the boat, so 30-ish years. That said, effective life of a reactor is something the Navy tracks closely, and depending on the life of the boat, the life left in the reactor, some boats are decommissioned as they get close to the end of their fuel life, and others get re-fueled. (And in the case of the USS San Francisco, who had recently been refueled before it hit an underwater mountain, they cut off the front half of the submarine and welded the front half of a recently-decommissioned submarine on, because the reactor and fuel was too valuable to go to waste)
French (& American and Royal Navy) submarines are nuclear powered. No fuel necessary.
They do have measures of "nuclear fuel" remaining, but it lasts about 30 years (at least in the American boats) so generally doesn't impact day-to-day considerations.
While I'm 100% positive the details of operational concerns like this are classified, there are 2 distinct types of submarines today with 2 different objectives:
1) Attack Submarines (e.g. Los Angeles-class & Virginia-class for USN) which usually roam within a designated operations area, surveilling, tracking, and generally keeping tabs on other nations' surface & sub-surface fleet dispositions. These subs typically have multi-week sorties and may intermittently surface for surveillance & comms.
2) Ballistic Missile Submarines aka "Boomers" (e.g. Ohio-class for USN) which are given a strategic area in which to operate and their objective is to remain silent & undetected, waiting for the hopefully-never-coming order to launch their SLBMs. These subs usually have multi-month sorties and often don't surface until the end of their patrol.
Clearly the Ballistic Missile Submarines surfaces intermittently surface
for comms as well?
If not, they won't know when to set off their missiles making then not
very useful as a deterrent
I have often wondered how close to the surface they need to get.
I would presume retractable antennas could be extended from a sub
from a non-trivial depth.
Or cable attached to buoys
Or something much smarter that I have not thought about yet.
There's a couple of different "wake up" signals that can reach deeper into water. Their biggest limitation is very low bandwidth, so an attack sub will emerge (/send up a buoy on a tether) to get an updated tactical map.
Also highlighting the E-6B Mercury (and the upcoming EC-130J), which among other communication options has a 5-mile (!) VLF antenna it deploys vertically in midair (!!) to establish limited-bandwidth communications with submarines.
Yes, modern subs typically carry comms buoys. Some are tethered and allow for two-way communication. Others are transmit only and float up to the surface independently.
But there are VLF antennas that Ohio-class submarines have to receive low-data-rate comms while submerged.
Any reasonable communications have to be made while at periscope depth. (Which is subtly different than "having to surface"... at PD just the thin mast is out of the water.)
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-Intelligen...
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-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.
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Elevated CO2 in submarines absolutely impairs performance. One example: there was a guy on my boat who got migraines when CO2 got too high - he was useless. Luckily the fix is simple - just turn on another CO2 scrubber.
There's nothing special about a submarine that makes CO2 somehow different than anywhere else.