Can a submarine turn upside down?

A very long time ago I read about the story in the below link concerning a Soviet Philidelphia Experiment style…experiment…utilising a submarine. Supposedly the submarine followed a magnetic moebius strip path turning upside down once in every revolution.

Leaving aside the patent implausibility of the story I always wondered could a submarine even do that, turn upside down like that and still function safely?

Somehow I doubt it.

After making six patrols with some of the craziest captains you have ever met …

I guarantee you no submarine can turn upside down …

  1. You have personnel onboard that can’t stand on their heads
  2. You have cooling water for the reactor on nuclear submarines
  3. You have weapons with nasty little things called warheads
  4. There is always someone in the head (restroom for land people) and they would become quite upset

I was on a round bottom diesel submarine that did a 57 degree roll one time and I thought I was going to die being as how I was the lookout in the bridge and reached out touching the lull of the wave.

We did have one captain that would get the sub going as fast as he could and then roll off like a fighter jet going port and then starboard. He wanted to do a 360 but couldn’t figure out how to keep the batteries all in one place.

We had one captain that use to run around the Med at periscope depth without the periscope up with those big oil tankers coming out of the Suez Canal having a 60’ draft … now that’s what I call crazy.

He went on to be in the commander in charge of all submarines on patrol out of Colorado.

As far as I understand, the bottom of the bouyancy tanks are open on most submarine designs. It one were to turn upside-down, all the air in those tanks would be lost and the boat would achieve unrecoverable negative bouyancy.

I expect submersible experts to tell me that this has not been true since the German Type VII was designed.

Please disambiguate:

[li]He went on to be commander, out of Colorado, in charge of all submarines on patrol (everywhere).[/li][/ul]
[li]He went on to be commander in charge of all submarines on patrol out of Colorado (probably none).[/li][/ul]

I served on a 688 class, and I can second Mr. Quatro – there’s no way a submarine can turn upside down. If it did, it would be impossible to recover from and everyone would die.

A lot of submarine systems utilize gravity, and would not work properly upside down.

I asked this very question to one of our teachers in Nuke School. He dismissed the question as not worthy of a serious answer. I insisted. With an exasperated wave of his hand he said “I assure you, you cannot roll a submarine.”
Then, I realized how silly the question was. As a machinist’s mate and a student of nuclear power, it should have been obvious to me that gravity was necessary for pretty much everything mechanical in the power plant to function correctly.

For example, feed water would certainly end up in the secondary plant steam piping and eventually hit the turbine blades: not good. For that reason alone the power plant would be trashed.

I was going to ask this same thing. Is it just a humorously-phrased description of a promotion (#1 on your list), or a euphemism for “They stopped putting him in charge of things because he was nuts” (#2 on your list)?

Promoted into a desk job from which the only way out is retirement.

While the main ballast tanks (MBTs) are indeed still open on the bottom in modern submarine designs, they have no air in them when submerged, so there is no air to be lost if the sub were to invert while submerged. The MBTs are designed to either be full of air (when the sub is surfaced), or full of water (when submerged). Fine buoyancy control is achieved with the variable ballast tanks (VBTs), which are typically sealed tanks internal to the pressure hull.

That being said, the fact that the MBTs are open on the bottom means that an emergency ballast tank blow would not work if the sub were inverted.

In any event, subs still cannot safely turn upside down for a variety of other reasons, as previously noted.

Sure. A naval officer assigned to a staff billet in the mountains has received the unambiguous message “You’re done, kthxbye”.

(Maybe. In my stint at USSTRATCOM, I did see several gold dolphins on Lieutenant Commanders who looked (and were rumored) to still be on the track to their star. I guess it depends on the specific assignment… leadership or paper-pushing.)

Assuming all the crew were prepared and the reactor was shut down, is there any reason you couldn’t? Mr Quatro referred to missile warheads but I can’t believe the missiles are loose in their launch tubes. They must be held in by clamps or something, surely?

Except for the fact that NORAD is in Colorado which leaves open the possibility that the comment was in regards to the possibility that the captain was deemed appropriate for top level work.

That was my initial reaction. Is the guy sidelined or frontlined?

Murph the Surf? Now he was a freaking wingnut.:rolleyes:

this was tried early on. because of confusion on what ‘down periscope’ was meant resulting in a bent periscope then the practice was discontinued.

How 'bout an Immelman turn? That would take care of the gravity issue. Or maybe produce excessive G force? I assume the turning radious would be very large. Start deep, bring her up to top speed, order all non-essential personel (for this manuver) to lie on the deck and hold on tight, lift the bow, increase floatation, roll 180 degrees during the turn, and trim the boat horizontal at the top of the turn. If that were possible, two immelmans (change increase floatation to decrease floatation for the 2nd) would be a complete loop.

I hate when that happens. :smiley:

Aside from ruining the engineering machinery (water going the wrong way, even if the reactor is shut down), there would be no way to right the submarine and/or get it to the surface. The submarine and everyone aboard would die.

My thinking as well. Nearly all of the objections above assume upside-down=negative G, but aircraft can perform quite a few fully inverted dynamic maneuvers and still maintain positive loading. A sub should be able to loop, but I suspect not fast enough or tight enough to avoid negative loading over the top. A clover-leaf or barrel roll conserve more energy, but are very difficult to pull off without roll control surfaces, though it is not too hard to get a 2 channel RC glider to do a fair approximation of a barrel roll. A split-S (opposite of Immelmann ) is really the safest way to get upside down with positive G, but I don’t see a way to initiate the maneuver without roll, and you’d still need huge amounts of pitch plane authority for the exit.

Some of the responses seem to assume sub=nuclear power. Many navies still operate diesel electric subs. It would be considerably easier to modify one of these for inverted operation, since electric motors don’t care and batteries can be sealed and secured…but still no good reason to do so.

How fast do you think submarines go? :confused:

But other than that… :smiley:

Since water is hundreds of times denser (800+) than air, a submarine’s control surfaces would still be subject to considerable force at speeds much, much lower than those required by aircraft.

A submarine also has the option of controlling its own bouyancy. Increasing buoyancy aides on the upward half of the loop and decreasing buoyancy aides on the downward half.

I have no idea if looping a sub is even possible so please don’t reassign me to a desk in Colorado for discussing it. :smiley: