Polaris tubes stay on Cruisers?

[Archibald]

same diameter or close, both smaller than the launch tube diameter - d'uh

The Polaris was 54" in diameter while the Agena was 60" in diameter.

Yes, you have a point here. But Poseidon and Trident I - 74 inch in diameter - used the same tubes in the same submarines. The USN had found that bigger missiles could be carried if some stuff was removed from the tube. And at 74 inch, the Agena fits comfortably. Length (height ?) is not a problem either.

U.S. Submarine-Launched Ballistic Missiles

 

[NMaude]

I think you'll find that the USN would've been extremely reluctant for their SSBNs to be carrying missiles that had a stage carrying hypergolic-propellants in it, they were and are deeply suspicious and reluctant to have ordinance onboard a warship carrying liquid propellants.

 

[Archibald]

I figured that.

But don't underestimate the mighty attractivity of throwing 1000 pounds to orbit - Transit navigation satellites weighed much less than that - out of submarines. EARLY SPRING shows the USN badly wanted to use their brand new Polaris for many innovative missions, even if suborbital. Polaris-Agena stretches that to orbit at little cost.

Even surface ships however would be a stretch. And then there is NATO MLF proposal, which got Polaris tubes on italian cruisers; as boomers would be way too expensive for NATO medium powers. Except that a surface fleet would be easily wiped out in the early stages of WWIII.

Still one could build a PAGE capability from Italian cruisers since they had the tubes, plus Italy was a dynamic space power right out the 1960's: they build and launched Scout rockets under licence, from a modified oil rig out of Kenya coast !

The USN certainly hated the guts of liquid props & storables for the reasons you mention. Although I recently learned about the peculiar case of the Bullpup missile. That one started solid-fuel then shifted th storable props. Because they knew the Navy would never allows this, Reaction Motors came with a peculiar idea: the storable props were sealed at the missile plant. USN crews never had to bother about the dangerous props, the missile wasn't refueled. The fuel tanks were sealed at the plant, and only "opened" when firing the missile in flight.

Bullpups experience could be applied to the Agena, although it was bigger - seven tons instead of one ton, not that big of a stretch.

So much possibilities. Endless whatiffery potential. Guess why my TL has ballooned to 2500 pages ??!!!

 

[NMaude]

Except that a surface fleet would be easily wiped out in the early stages of WWIII.

That should be "Could" not "Would" as unless they were in port when the balloon went up any Soviet naval and/or aviation forces would have to actively look for them and such cruisers would no doubt be in their own cruiser equivalent of a CVBG.

 

[A Tentative Fleet Plan]

same diameter or close, both smaller than the launch tube diameter - d'uh

The Polaris was 54" in diameter while the Agena was 60" in diameter.

Yes, you have a point here. But Poseidon and Trident I - 74 inch in diameter - used the same tubes in the same submarines. The USN had found that bigger missiles could be carried if some stuff was removed from the tube. And at 74 inch, the Agena fits comfortably. Length (height ?) is not a problem either.

U.S. Submarine-Launched Ballistic Missiles

Not quite the same tubes. For the initial Polaris Submarines (which I believe never received Trident C4), to meet stringent requirements to protect the missiles from shock in the original Mk 17 Polaris Launch System, the Polaris missile was held by three pads or "stowage launch adaptors" inside the heavy machined steel launch tube, and the launch tube was in turn held in the submarine mount tube by oil-filled double-acting shock absorbers. The oil-filled shock absorbers were fitted as they retained a "null" which required significant force for them to deviate from, this enabling the precise positioning for the optical alignment required to ready the guidance system.

The opportunity to take advantage of a greater proportion of the volume of the submarine mount tube only came as a result of investigating the use of truck-launched Polaris for the MLF. As the original stowage tube was too heavy, and the the stowage launch adaptors were incapable of supporting the missile when stored horizontally on a truck, Westinghouse came up with a design where the missile would be supported by foam-padded resin-reinforced fibreglass panels with heavy duty zippers up the sides which would be undone after the missile was loaded into the launch tube. This would support the missile regardless of orientation and would simultaneously remove the need for the heavy machined launch tube, the launch tube itself now being cushioned by foam springs. A pair of demonstration trucks were built, but when the MLF died, Westinghouse marketed this to the Navy as a means of increasing the number of missiles per submarine (as it would require smaller submarine mount tubes hence more could be installed within a given length). The Special Projects Office realised it would also ensure that larger missiles could be launched from existing tubes.

This later Mk 21 Polaris Launch System would be introduced from James Madison onwards, but would only have the potential for back fitting larger missiles, primarily replacing the liquid springs suspending the launch tube within the mount tube with polyurethane foam, but retaining the liquid springs on which it rested, as were the existing stowage launch adaptors.

The Mk 21 would modified into the Mk 24 for launching Poseidon via a modular replacement with the thin launch tube and padding replacing the earlier machined launch tube and stowage launch adaptors taking full advantage of Westinghouse's innovations for the truck-based MLF system.

Source: From Polaris to Trident, Graham Spinardi

 

[Archibald]

"Truck launched Polaris" ? OMFG. How could I miss that ? Do we have a thread for that on this forum ?

 

[GTX]

"Truck launched Polaris" ? OMFG. How could I miss that ? Do we have a thread for that on this forum ?

Indeed we do: https://www.secretprojects.co.uk/threads/polaris-ssbm-as-land-based-srbm.8231/

 

[sferrin]

Ninja'd, damn it.

I would extend the whatif to "ballistic missiles without nuclear warheads for everything".

One example: loaded with conventional explosives and used as "surrogates" strike vehicles or bombers.

Another example: let's suppose a very different Falklands. Port Stanley airfield must be wrecked.
So the British send a R-class nuclear submarine, it fires a Polaris, except with a very different warhead: some kind of "ballistic Durandal" or "conventional explosive cluster bomb". The Polaris warhead explodes over the airfield and rains thousands of bomblets all across the tarmac, thoroughly devastating it.

In a few words "Prompt global strike" ICBM plans touted by Bush 43 circa 2004 (from memory).

thoughts ?

My thoughts exactly.

Conventional theatre ballistic missiles with cluster munitions and FAE clearing the way for carrier launched strike planes during Desert Storm, or launching Prompt Global Strike deep penetrators at Tora Bora?
Ship launched ballistic missiles could fling satellites to keep communications going, or their large tubes could carry ABM missiles.

There was also talk of shooting scramjet ballistic missiles out of 16" guns, ~400nm in 9 minute!

 

[Scott Kenny]

Weird, I could have sworn I replied to this thread already...

Before Polaris was put out to sea, submarines weren't their only host platform; the USN had their Long Beach and Albany cruisers "fitted for, but not with" with eight Polaris tubes. Also, the Italian Navy and their Cruisers held provisions for Polaris tubes. Still, these plans were dashed after the Cuban Missile crisis and the quick build-up of American SSBNs.

So, what if the surface navy kept their nuclear missiles?

Personally, I think if the SWO's got their way, we might see the Long Beach turn into a class of ships that led independent Surface Action Groups. The "DLG Frigates" would still be procured for air defense, but CGN (CAGN) Cruisers would be built in the 60s and continue their historical roles; more or less, these are the "Strike Cruisers" but built to 60s standards so Talos, Mk11 launchers, Asroc, and probably no guns, unfortunately. But what other offensive weapons might arise if the surface navy got more of the budget? Something of the equivalent to Styx or Moskit anti-ship missiles? How much earlier could Tomahawk or an equivalent come into service?

No, the Long Beach herself was very firmly a carrier escort. It'd really need something like a Des Moines class to be off by herself or in a Surface Action Group with a quartet or octet of Polaris tubes.

Ninja'd, damn it.

I would extend the whatif to "ballistic missiles without nuclear warheads for everything".

One example: loaded with conventional explosives and used as "surrogates" strike vehicles or bombers.

Another example: let's suppose a very different Falklands. Port Stanley airfield must be wrecked.
So the British send a R-class nuclear submarine, it fires a Polaris, except with a very different warhead: some kind of "ballistic Durandal" or "conventional explosive cluster bomb". The Polaris warhead explodes over the airfield and rains thousands of bomblets all across the tarmac, thoroughly devastating it.

In a few words "Prompt global strike" ICBM plans touted by Bush 43 circa 2004 (from memory).

thoughts ?

The challenge there is rather abysmal Polaris CEP. Even Poseidon isn't really accurate enough for conventional warheads.

You'd need terminally guided, Maneuverable Reentry Vehicles.

There is also a danger of escalation. How does the target nation know if the ballistic missile heading their way is conventional or nuke???

You don't, which is what killed the Conventional Trident/Prompt Global Strike ideas.

It was primarily a countervalue rather than a counterforce weapons system, so primarily cities, industrial areas and other civilian/non-military targets, though the others you mention would have been important secondary targets where possible (with preference given to relatively non-hardened facilities). Though the USN may have allowed some confusion on Congress' part to develop over exactly what Polaris was intended & capable of taking out, in order to keep the program going. If Congress had known the full truth of affairs it is highly unlikely they would have allowed Regulus II to be cancelled to in order free up more funds for the ever ravenous Polaris, for example.

Nope, Regulus as a submarine weapon was dead. Too many submarine admirals with combat time while under air attack in WW2 saying "how long does a Regulus boat have to stay on the surface again?" to let that happen. (20-30 minutes from surfacing to launching the first Regulus, about 5 minutes between launches, and about 5min from last launch to submerging again, BTW). Regulus was much better served as a surface ship weapon, despite the obvious approach of a surface ship to someone's coast. "Innocent passage" and all.