# Can modern submarines sit on the ocean bottom? **URL:** \ **Category:** Factual Questions\ **Created:** [January 23, 2017, 9:07pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972 "2017-01-23T21:07:09Z")\ **Posts on this page:** 13\ **Page:** 4
**Author:** ![Dana\_Scully](https://avatars.discourse-cdn.com/v4/letter/d/5daacb/32.png) [@Dana\_Scully](https://boards.straightdope.com/u/Dana_Scully)\ **Post date:** [January 27, 2017, 10:03pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/61 "2017-01-27T22:03:40Z")
> [@robby](#): > > **LSLGuy** has covered most of the salient points. > > Nuclear-powered submarines do indeed need a constant flow of seawater for their heat exchangers and turbine condensers, and clogging up the intakes with sediment would be detrimental. This is less of a issue with diesel-electric subs, but their endurance is only a small fraction of that of the nuke boats. > > Another consideration that the ocean bottom is not a featureless, smooth surface as is commonly imagined. Instead, it has topography just like dry land (which is typically covered with sediment). This mean that a potential bottom-sitting operation would have to conducted very carefully, to avoid striking an outcropping or ending up in a precarious orientation. > > Boomers on patrol don’t sit on the bottom, nor do they routinely hover. Instead, they proceed at a fast enough speed to maintain [steerageway](https://en.wiktionary.org/wiki/steerageway) so that their rudder and planes work. (Hence the unofficial boomer slogan of “three knots to nowhere.”) > > P.S. Just noticed that this will be my 5,000th post! (And it’s only taken me 16 years…) Congratulations! 🙂 ---
**Author:** ![Dana\_Scully](https://avatars.discourse-cdn.com/v4/letter/d/5daacb/32.png) [@Dana\_Scully](https://boards.straightdope.com/u/Dana_Scully)\ **Post date:** [January 27, 2017, 10:07pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/62 "2017-01-27T22:07:48Z")
> [@Kobal2](#): > > nitpick : that’s one possible explanation - but the truth is, we have no clue why (some) whales breach. Maybe it’s just their way of having fun; I’d breach if I could 😉 ---
**Author:** ![Kobal2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kobal2/32/20_2.png) [@Kobal2](https://boards.straightdope.com/u/Kobal2)\ **Post date:** [January 28, 2017, 12:38am UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/63 "2017-01-28T00:38:19Z")
> [@Dana\_Scully](#): > > Maybe it’s just their way of having fun; I’d breach if I could 😉 Oh absolutely. I breach out of bed every morning. My GF isn’t amused, however. ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [January 28, 2017, 3:41am UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/64 "2017-01-28T03:41:47Z")
> [@iiandyiiii](#): > > The answer (for US subs currently or recently in service) may be classified. I should know (since I served on a sub) but I don’t remember exactly whether it’s classified or not (but I do know the answer to the OP question). > > You’re welcome for this extremely helpful answer. Another former submariner here. We were permitted to say that our boat’s\* maximum depth rating was “in excess of 2000 feet.” \*(both boats I served aboard were Sturgeon-class fast-attack subs) ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 28, 2017, 3:52am UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/65 "2017-01-28T03:52:55Z")
- checks package literature on my Rolex \* Oh hell. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [January 28, 2017, 5:04am UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/66 "2017-01-28T05:04:24Z")
> [@Leo\_Bloom](#): > > Do submarines always surface horizontally if they can help it? The usual way for a submarine to surface in the open ocean (not under the ice) is to be moving and to use its planes to drive to the surface. Once at the surface (at this point, the sub has “broached” the surface, but is still more or less neutrally buoyant), a snorkel mast is extended and a low-pressure blower is run to empty the main ballast tanks (MBTs) of seawater. So the upshot is that the sub surfaces with a slight up angle (of a few degrees), and then becomes more horizontal as the MBTs are emptied. An emergency blow to the surface uses high pressure air to empty the MBTs, causing the sub to rise to the surface much more rapidly with a much larger up angle. > [@Leo\_Bloom](#): > > …What is the energy expenditure/wear and tear equation when–in those stunning photos from the Arcitic, a sub just all of a sudden _is there_…it looks like it came up from the ice horizontally (all though I suppose it may have surfaced on an angle, settled down, and then the snow gathered for a flat horizon. > > How does it do it? I was actually onboard the first 688I (improved _Los Angeles_-class) submarine to break through the polar ice back in the early '90s. This is a carefully controlled evolution to avoid breaking anything. The sub uses a so-called “normal blow” high-pressure air system to carefully empty the MBTs and slowly push up through the ice. The sub can either surface through the ice horizontally (in which case you can only exit the submarine via the sail), or with a slight up angle, in which case a forward hatch can be exposed (with a chainsaw), which makes it easier to exit and enter the boat. Snow does not gather on the sub after surfacing. There’s actually very little humidity or precipitation in the Arctic air. Instead, there is simply residual ice on the hull, along with the ocean refreezing around the top of the sub within a matter of minutes. As for wear and tear on the sub, my boat did several dozen through-ice surfacings during our first ICEX, and the boat got pretty dinged up (mostly cosmetic damage). Nevertheless, we had to go into an unscheduled drydocking for minor repairs a few months later. > [@Leo\_Bloom](#): > > Come to think of it, if it needs/wants to surface under-and-through an ice sheet, it matters a great deal if the ice is a few inches or 20 (?) feet deep, doesn’t it? Yes, it matters a great deal. A sub can surface through ice easily up to 3-5 feet thick, at which point it gets progressively more difficult. At some point it becomes impossible to break through, which is somewhat nerve-wracking should you have an emergency. For example, if you can’t access the surface, you can’t run the emergency diesel generator in an emergency. > [@Leo\_Bloom](#): > > Does the bridge (where the Skipper stands…not sure if thats called the bridge)… The structure on top of the sub is called the “sail.” (In WWII, it was referred to as the “conning tower.”) When the sub is operating on the surface, the bridge is located at the top of the sail. > [@Leo\_Bloom](#): > > …gauge that ahead of time, maybe by sonar pings differing on the density of the ice mass? The density of the ice does not change, but the thickness does. Thickness is determined by simply bouncing sonar vertically up, and then comparing the distance to the ice to the sub’s depth (which is determined by sea pressure). The difference between the two is the thickness of the ice. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 28, 2017, 2:16pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/67 "2017-01-28T14:16:10Z")
Wow **robby**. Thanks for every detail. Fascinating. Not breaching but broaching. Noted. A “bridge” is still the word on a sub, like in a ship and a starship cruiser. Noted. I thought it couldn’t be plain old distance-pinging because I forgot in general you already know where the top of the ice sheet is. (Everything else: noted :)) ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 28, 2017, 2:23pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/68 "2017-01-28T14:23:03Z")
On your ice missions, did every crew member get a chance to stretch his legs, breather fresh air, throw a snowball or two? Seems a shame otherwise. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [January 28, 2017, 2:56pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/69 "2017-01-28T14:56:05Z")
> [@Leo\_Bloom](#): > > On your ice missions, did every crew member get a chance to stretch his legs, breather fresh air, throw a snowball or two? > > Seems a shame otherwise. Yes, absolutely, on numerous occasions. We called it “ice liberty.” ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [January 28, 2017, 3:11pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/70 "2017-01-28T15:11:19Z")
> [@Leo\_Bloom](#): > > …A “bridge” is still the word on a sub, like in a ship and a starship cruiser. Noted. Except that on a sub, the bridge is not used once the submarine submerges. Indeed, the bridge (which is the open area in the top of the sail used for surface operations) is outside the pressure hull, and is flooded with seawater once the submarine submerges. During surface operations, the Officer of the Deck (OOD) and the “[conn](https://en.wikipedia.org/wiki/Conn_(nautical))” are on the bridge. Immediately prior to submerging, the OOD (and the conn) move down to the control room (where the periscopes are utilized), and the watertight hatches are shut. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [January 28, 2017, 11:23pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/71 "2017-01-28T23:23:56Z")
> [@robby](#): > > Well, I did say that “they have lead ballast in the bottom of the boat or in the keel itself.” Per [wikipedia](https://en.wikipedia.org/wiki/Keel): “A secondary purpose of the keel is to provide ballast. Keels are different from centreboards and other types of foils in that keels are made of heavy materials to provide ballast to stabilize the boat.” Just drifted past again, and I thought I’d clarify: I don’t think that any sailing dinghies, or any Olympic-class sailboats (since they dropped keel boats) use “ballast”. That is: “ballast” is not a part of the stabiltiy of all “sailboats”. (Except when the term is used to include the weight of the crew, which I think is outside the present discussion, because the crew moves around to maintain the ballance, so it’s not like a submarine depending on “ballast” for stability underwater) ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [February 1, 2017, 6:29pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/72 "2017-02-01T18:29:20Z")
> [@Leo\_Bloom](#): > > On your ice missions, did every crew member get a chance to stretch his legs, breather fresh air, throw a snowball or two? > > Seems a shame otherwise. I did two runs under the ice while aboard the _Tautog_. First one was a winter expedition, and “ice liberty,” such as it was, consisted of being issued an insulated rubber suit (head-to-toe; we called them “Gumby suits”) and an ice pick, and spending half an hour at a time chipping ice off the sail planes, so that when the time came we’d be able to submerge again. Our second ice run was at the height of summer; for that one, they set up a barbecue grill topside (fueled by oxygen-generating candles), and we had a weenie roast with lots of fun and games (one of the forward ETs actually stripped down and streaked the North Pole). ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [February 1, 2017, 7:47pm UTC](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972/73 "2017-02-01T19:47:33Z")
Interesting - as it happens, Wiki has some pics of _Tautog_’s icy sojourns: [USS Tautog (SSN-639) - Wikipedia](https://en.wikipedia.org/wiki/USS_Tautog_(SSN-639)#1980.E2.80.931997) [Previous page](https://boards.straightdope.com/t/can-modern-submarines-sit-on-the-ocean-bottom/777972.md?page=3)