The Navy's SSGN crossroads

Commanders love the Navy’s four converted Ohio-class guided missile submarines. They loved how the USS Florida was available to fire 93 Tomahawk land-attack missiles at Libya on short notice, from a hiding place beneath the Mediterranean. They love dropping cryptic hints about how Naval Special Warfare uses the ships. And they loved, loved, loved when three of the boats suddenly were photographed in different places in the Western Pacific at the same time – one imagines a room full of Chinese naval intelligence officers doing a spit-take onto their computer monitors.

Commanders love the Navy’s four converted Ohio-class guided missile submarines. They loved how the USS Florida was available to fire 93 Tomahawk land-attack missiles at Libya on short notice, from a hiding place beneath the Mediterranean. They love dropping cryptic hints about how Naval Special Warfare uses the ships. And they loved, loved, loved when three of the boats suddenly were photographed in different places in the Western Pacific at the same time – one imagines a room full of Chinese naval intelligence officers doing a spit-take onto their computer monitors.

The four Ohio SSGNs are on their second careers, however, and they will not last forever. Given how much the Navy brass has loved its current ships, how will it replace them?

Rear Adm. David Johnton, the program executive officer for submarines, left that question open last week at the Naval Submarine League conference. The only thing that’s clear for now is that a potential replacement SSGN will not be its own brand-new ship – the Navy’s Ohio-replacement boomers may only be able to squeak through as it is, and a second new submarine might be a boat too far. Fortunately for the Navy, there’s a potential solution at hand.

First, some background:

Starting with the fast-attack sub USS North Dakota, now under construction, the Navy is adding two 87-inch tubes to the ships’ bows, replacing 12 smaller vertical tubes built on earlier ships for their Tomahawk missiles. (Later model Los Angeles-class subs also have these 12 VLS tubes in their bows.) The new “Virginia payload tubes” can carry the same number of missiles – six Tomahawks per tube, in a circular launcher developed for the Ohio SSGNs – but if you take those weapons out, now you’ve got a big tube that can accommodate almost anything you want.

This is where eyes in the submarine force start to glimmer: Think of the ways SEAL special operators might use a big open space like that on a new attack submarine, or think of the potential new unmanned underwater vehicles it could unleash.

Now we return to the SSGN problem: General Dynamics’ Electric Boat submarine yard has pitched an addition to the Virginia-class fast attack submarines it calls the “Virginia payload module.” (pdf) This would add four more of these 87-inch tubes in a section aft of the ship’s sail, giving a potential future Virginia a total of six big tubes. (If you take a look at the GD illustration, remember that the ship’s torpedo tubes are numbered 1 through 4, which is why the big new notional tubes start at 5 and run to 10.)

So – will this suggestion preserve the dedicated SSGN capability of which the Navy has grown so fond? Maybe – Johnson and other submarine officials haven’t committed to it yet. It raises as many questions as it answers: Would a stretched, 471-foot Virginia be a portly attack sub or a svelte missile boat – where would it fit into the submarine Navy’s playbook? Would you build four Virginia’s with the SSGN extension to replace the Ohios one-for-one, or would you keep running them off?

One hint came from Capt. Michael Jabaley, program manager for the Virginia class. The Navy needs as many attack boats as it can get to help fill a projected gap when it’ll have more missions than submarines. So if the shipyards keep delivering boats smoothly and Congress goes along with more multi-year buys, the Virginia class could grow from its original program of 30 ships to as many as 45 or 50, he said – out to a “Block 7” variant. (The North Dakota will be the first ship of Block 3.)

With those kinds of numbers, a few stretched Virginias start to sound inevitable, though Navy officials were careful to insist nothing is set in stone. That even includes what the augmented ships would be called.

“I don’t know,” Johnson said. “If we do go down the Virginia payload module path, this is a good problem – is that an SSN or an SSGN, or something in between?”