Can a submersible destroyer be useful?

[Ronny]

The main advantages of a submarine is stealth and the fact that it literally can only be attacked by torpedo or depth charge which has very limited range. But submarine are very vulnerable to aircraft since it can't detect them from long range and can't attack them from long range either
The main advantages of a common destroyer are the ability to see very far with its radar and can provide air defense over a large area. But a destroyer is vulnerable to long range attack and can be detected from great distance.
So, what if we mix them together?.
Like what if we make a submarine that has very tall mast with radar on top of it and equipped it with long range SAM like normal destroyer. The mast should be tall enough so that it raise 14-15 meters above water even when the submarine/destroyer body is still underwater.
So we have for ourselves a ship that can detect and attack aircraft from very long range. Yet at the sametime can be very stealthy and can deny any missile attack by going down bellow the water.

 

[burunduk]

USN had special submarines for radar picket service, although without SAM. It seems similar to your idea.

USS Sailfish (SSR-572) - Wikipedia

en.wikipedia.org

 

[EwenS]

Maybe there are clues in the past, albeit pre-radar, big gun days. They didn’t seem to work out too well then.

British M-class submarine - Wikipedia

en.m.wikipedia.org

French submarine Surcouf - Wikipedia

en.m.wikipedia.org

Back in the 1970s the Blowpipe missile was adapted for submarine use and tested in HMS Aeneas. But it never caught on even with the people who had requested the capability.

Blowpipe (missile) - Wikipedia

en.m.wikipedia.org

So the mixing of roles of subs with something else has been tried before and hasn’t caught on. Got to ask yourself why? One reason is that subs rely on stealth for their success. All these proposals result in that being sacrificed to gain another capability.

It is easy to say oh it can dive to evade any incoming missile attack. But that ignores the fact that your enemy knows, at least roughly, where the sub is and ASW forces, surface or air, can be deployed to eliminate the threat. Alternatively the opposing task force will route around the danger area.

IIRC some of the problems of mixing sub roles with other roles, specifically aviation, were discussed in a chapter in this book, but there will be some read across to your proposal.

The Hybrid Warship: The Amalgamation of Big Guns and Aircraft: Amazon.co.uk: R.D. Layman (author): 9781557503749: Books

Buy The Hybrid Warship: The Amalgamation of Big Guns and Aircraft by R.D. Layman (author) (ISBN: 9781557503749) from Amazon's Book Store. Everyday low prices and free delivery on eligible orders.

www.amazon.co.uk

 

[ReprobateJoeshmoe]

Maybe there are clues in the past, albeit pre-radar, big gun days. They didn’t seem to work out too well then.

British M-class submarine - Wikipedia

en.m.wikipedia.org

French submarine Surcouf - Wikipedia

en.m.wikipedia.org

Back in the 1970s the Blowpipe missile was adapted for submarine use and tested in HMS Aeneas. But it never caught on even with the people who had requested the capability.

Blowpipe (missile) - Wikipedia

en.m.wikipedia.org

So the mixing of roles of subs with something else has been tried before and hasn’t caught on. Got to ask yourself why? One reason is that subs rely on stealth for their success. All these proposals result in that being sacrificed to gain another capability.

It is easy to say oh it can dive to evade any incoming missile attack. But that ignores the fact that your enemy knows, at least roughly, where the sub is and ASW forces, surface or air, can be deployed to eliminate the threat. Alternatively the opposing task force will route around the danger area.

IIRC some of the problems of mixing sub roles with other roles, specifically aviation, were discussed in a chapter in this book, but there will be some read across to your proposal.

The Hybrid Warship: The Amalgamation of Big Guns and Aircraft: Amazon.co.uk: R.D. Layman (author): 9781557503749: Books

Buy The Hybrid Warship: The Amalgamation of Big Guns and Aircraft by R.D. Layman (author) (ISBN: 9781557503749) from Amazon's Book Store. Everyday low prices and free delivery on eligible orders.

www.amazon.co.uk

I mean it would not be unreasonable to add some short range missiles in vertical launch cells, or something else with a more range to poke and annoy enemy aircraft, and destroy them. As far as I am aware, I have not seen a effort to amalgamate surface and submersible tech to maximize stealth both above and below water, though I am sure many of you are aware of such a thing, if so please point to me to it. It would be interesting if there was such a thing.

 

[Ronny]

It is easy to say oh it can dive to evade any incoming missile attack. But that ignores the fact that your enemy knows, at least roughly, where the sub is and ASW forces, surface or air, can be deployed to eliminate the threat. Alternatively the opposing task force will route around the danger area.

I was thinking a long the line that , it will operate semi submersible most of the time, operate similarly to an anti air destroyer
It can intercept anti ship missiles, aircraft with its missiles, but if the captain consider that the anti ship volley is too big to intercept, then he can order diving to avoid the attack in the last moment. Then the ship can resurface later. Anti submarine force has pretty short attack range so they can be easily intercepted with SAM and anti ship missiles

 

[shin_getter]

I was thinking about this, and I think the main problem isn't engineering but in role.

In the surface ship escort role, survivability of the escort isn't that important since most of the munitions is trying to kill the high value target being escorted and optimizing for the survival of the target is the point of the formation.

However a submarine with anti-air capability is potentially useful in a number of other roles.
1. Offensive surprise anti-air attacks: Have a sub surface and take out high value force multipliers like tankers/AEW/etc by penetrating a poorly defended vector into the enemy rear. If you force a stack of F-22 or B-21 to ditch, or open a ISR hole to let your 5th gen complete the ASBM kill chain, trading a sub for it can be worth it.

2. Defensive sub-centric anti-ASW air defense. Subs, especially diesel electric, can be suppressed by air power and unable to snorkel or maneuver altogether. Anti-air weaponry can defeat the problem. and this may not cost much against low end aircraft like helicopters or drones. In some cases this is do or die and the historical cause for submarine Anti-Air development.

------
That said, just because one can think of neat tactics for theoretical platform doesn't mean it is a practical idea. The cost and performance of such a vehicle is a big question and it is also constantly changed by technology and industrial factors. Would really need engineers look at the thing.

Anti submarine force has pretty short attack range so they can be easily intercepted with SAM and anti ship missiles

I think a big problem is that a submarine have relatively tiny internal volume and payload for cost, and you'd run out of interceptors if a surface ship or significant aircraft force is in range to shoot at you. As a escort, your'd also run out of interceptors quickly and get your protected asset overwhelmed.

In a world of high interception effectiveness and magazine depth competitions (that is needed for heavy surface ships to survive) more missiles on cheap hulls should be the effective way to go.

In a world of low interception effectiveness, there is only ninjas sniping each other and no one would escort....

-----
Thinking about this a bit more, the nature of the air defense systems really do matter. If powerful air defense systems is only a matter of monetary cost but not in volume or mass, than adding it to a submarine is not too unreasonable since it wouldn't cost too much more than a surface ship. (since most of the cost is in the weapon system and not in the hull or propulsion) If air defense systems take huge volume (but not much in direct costs) that demands a big pressure hull with tons of aftereffects on propulsion, then a submarine may cost vastly more than a surface ship with the same air defense performance as hull costs balloon.

 

[DWG]

Destroyers are expensive.

Submarines make destroyers look cheap.

We have two missions for medium sized surface combatants: AAW (aka destroyers) and ASW (aka frigates).

The AAW role requires you to be on the surface, with a big radar and deep magazines stuffed with area defence SAMs. Big radars, especially, and extensive VLS magazines are problematical for submarines.

The ASW role requires you to be on the surface (to launch helos), with a VDS, and potentially, but not necessarily, your own ASW weapons. A submersible can handle the sonar side, and has its own ASW weapons, but it's a particularly poor platform for a helicopter (cf HMS M2).

So a hybrid submersible isn't a good AAW platform, and while you could potentially use one as an ASW platform, a pure submarine, or a pure surface vessel, would do it better.

Just adding the VPM to the Virginia class pushes the cost from $2.8m to $3.4m, and that's only 28 VLS tubes, a Burke has 96, and that's without Aegis. The SPY-6 for the Flight III Burkes is about $300m/set, without Aegis. And of course adding Aegis and radars means adding mass and volume - deckhouses to support it, processor space to run it, CIC space to operate it, plus power and cooling, on top of the mass and volume you are already adding for VLS. And as you add mass and volume you have to scale the hull to fit it, and to fit the ballast tanks to offset the added displacement, and then the bigger engines to power the bigger hull. So a submersible equivalent to a Burke is likely to run you $4-5Bn and come in at a svelte 15,000t+.

 

[Vanessa1402]

That ship can be very useful to face CBG. Launch ashm at the fleet from afar and finish off any fighters and patrol airplane with SAM

 

[TomS]

That ship can be very useful to face CBG. Launch ashm at the fleet from afar and finish off any fighters and patrol airplane with SAM

But what is this accomplishing that an SSGN doesn't? If you can kill the carrier with AShM, any aircraft it carried are gone, either sunk with the ship or desperately looking for a safe divert airfield within range before they run out of fuel.

 

[Ronny]

That ship can be very useful to face CBG. Launch ashm at the fleet from afar and finish off any fighters and patrol airplane with SAM

But what is this accomplishing that an SSGN doesn't?

It can intercept the retaliation attack from something like this

 

[GruntFox]

You're mixing two different mission types that are contradictory to each other. That makes them useless.

Then there is the fact that as lasers continue development, blue-green lasers are going to be a thing and tell torpedoes where to stuff it... at least not without having your torpedo launches go full-on Macross Missile Massacre levels of spam.