Can subs go 'belly-up' on the bottom?

[ColonelMolerat]

The manual mentions that, in real life, subs whose max depth exceeds the depth they're in can go 'belly-up' to reduce active sonar echo (page 134).

Is this modelled in-game? Would it make a difference? Should I be taking advantage of it somehow?

[Rory Noonan]

Seems to be. My favourite tactic with a diesel sub is to get in the path of an oncoming ship, go to the bottom and sit and wait. Seems like the active sonar is less effective at detecting me.

Edit:
Actually, confirmed that it is modelled. Run the attached save and see the two subs equal distance from the FFG; one on bottom and one a bit above the bottom. The 'floating' sub gets detected while the FFG can practically drive right over the sub sitting on the bottom without detecting it.

[MR_BURNS2]

I usually stay in the middle of the layer when cruising or when i just don't want to be found, works best most of the time.

You can find a lot of good tips here:

tm.asp?m=3876405

[ColonelMolerat]

ORIGINAL: apache85

Seems to be. My favourite tactic with a diesel sub is to get in the path of an oncoming ship, go to the bottom and sit and wait. Seems like the active sonar is less effective at detecting me.

Edit:
Actually, confirmed that it is modelled. Run the attached save and see the two subs equal distance from the FFG; one on bottom and one a bit above the bottom. The 'floating' sub gets detected while the FFG can practically drive right over the sub sitting on the bottom without detecting it.

Ahh, I had thought 'reduce active sonar echo' was to improve the sub's own active radar somehow, rather than to reduce the echo they produce from enemy sonar.

Any idea why they go belly-up, rather than just lying on the bottom?

[Rory Noonan]

Would have thought it was poor terminology--likely meaning the the same thing; there is no benefit from turning a sub upside down that I'm aware of, and many, many problems.

[Dysta]

I was mistaken the meaning of 'belly-up', as a sub is right under the 'belly' (keel) of the surface ship for a while. [X(]

[ColonelMolerat]

Would have thought it was poor terminology--likely meaning the the same thing; there is no benefit from turning a sub upside down that I'm aware of, and many, many problems.

And there I was, picturing the poor submariners standing on the ceiling, making sure everything was securely nailed to their (now upside-down) desks!!!

[SeaQueen]

The idea is the same as when aircraft or cruise missiles fly low in an attempt at becoming "lost in the clutter."

A submarine on the bottom might become "lost in the clutter" too. In radar land they call it "clutter." In sonar land they call it "reverberation." It's the same thing. It's essentially all returns you get off of things you're not really interested in and cloud up your screen (e.g. fish, irregularities in the bottom, vegetation). It's a way of manipulating the reverberation level (RL) in the active sonar equation to one's advantage. Of course, on the other hand, advanced signal processing intended to filter out reverberation ought to make this kind of tactic harder.

It's also important to note that submarines (just like ships in general) often have various sorts of intakes on their bottom which might preclude this sort of behavior due to the risk of them being clogged. It'd be a shame if your nuclear reactor's cooling system sucked in a ton of mud and bottom-dwelling creepy crawlies. Such events tend to go badly. Diesel submarines might have similar problems with water cooled heat exchangers used for their diesel engines or generators although it's less immediately pressing. I'm not sure how it'd effect air independent propulsion like Stirling engines or hydrogen fuel cells. They typically carry their own oxidizer in the form of liquid oxygen. That might provide sufficient cooling so that they don't need intakes. On the other hand, to store it they need refrigeration, so they might need more cooling because the refrigerator will be dumping waste heat somewhere. Huuum... Something to think about...

Nothing is simple.

ORIGINAL: ColonelMolerat

The manual mentions that, in real life, subs whose max depth exceeds the depth they're in can go 'belly-up' to reduce active sonar echo (page 134).

Is this modelled in-game? Would it make a difference? Should I be taking advantage of it somehow?

[FTBSS]

Yeah Belly up is a not literal, no submarine actually flips upside down in fact impossible on Nuclear submarines for safety reasons in fact the angle that a sub is capable of yawing, pitching and rolling are highly classified.

[ultradave]

Yeah, a nuclear reactor would have some problems being upside down, the most obvious being steam and water in the wrong parts of the steam generators, pressurizer steam bubble ending up in the primary loop (very bad - very very bad). This would apply to any PWR anywhere - sub, surface ship, land based too (think portable SMR)