The U.S. Navy is looking to restore its ability to reload its ships’ vertical launch systems at sea, which could be a dramatic logistical game changer in the planning and execution of high-intensity contingencies against peer competitors.
This encouraging revelation comes from an exclusive one-on-one conversation with Chief of Naval Operations John Richardson following his remarks at the U.S. Naval War College’s 2017 Current Strategy Forum last month.
After discussing the means by which the Navy seeks to ensure its forward-deployed naval forces remain survivable and up-to-date with the latest tactical and technological innovation, Admiral Richardson said in reference to vertical launch system (VLS) underway replenishment, “we’re bringing that back.”
Since its operational debut in 1986 aboard the sixth Ticonderoga-class cruiser, USS Bunker Hill, the Mark 41 vertical launch system and its successor the Mark 57 have become the main battery of the preponderance of the Navy’s surface fleet, while the Mark 45 has become the principal means of deploying cruise missiles aboard submarines. Vertical launch systems are among the most adaptable weapon mounts that the Navy fields, allowing a ship to carry a variety of defensive and offensive missiles in the same shipboard infrastructure, and to fire them in rapid succession.
However, unlike other Navy striking arms like the carrier air wing, vertical launch systems cannot, at present, be practicably resupplied and reloaded while at sea. Once a VLS-equipped ship or submarine expends its missiles, it must withdraw to an equipped friendly port to replenish. This represents a significant operational liability, especially in high-intensity combat scenarios against peer adversaries. U.S. surface combatants currently in service have 80–122 VLS cells per ship, each cell being capable of accommodating either one large-diameter missile (such as Tomahawk cruise missiles, rocket-assisted antisubmarine torpedoes, and SM-2, SM-3 and SM-6 Standard Missiles) or four small-diameter Evolved Sea Sparrow Missiles for local air defense out to thirty nautical miles. Ships therefore could potentially run through their stocks startlingly quickly. In April’s punitive strike on the Syrian government’s airbase at Shayrat, fully sixty Tomahawk cruise missiles were launched from the destroyers USS Porter and USS Ross against a single, stationary target that was not actively evading or returning fire, and the next day USS Porter left station for a six-day transit back across the Mediterranean to its homeport of Rota, Spain to reload and begin preparing for its next patrol. And despite this significant expenditure of ammunition, the targeted airfield reportedly resumed flight operations several hours after the strikes concluded.
“Out of Action for an Unacceptable Period of Time”
Leading naval thinkers have identified the Navy’s current inability to reload vertical launch systems outside of port as a serious vulnerability. Bryan Clark, a retired nuclear submariner at the Center for Strategic and Budgetary Analysis and coauthor of a fleet-architecture study published by CSBA earlier this year, explained, “In our analysis, we expect surface combatants to quickly expend their VLS magazines even in a small confrontation and need to leave the conflict area to reload.” Bryan McGrath, a retired destroyer skipper at the Ferrybridge Group and the Hudson Institute and a coauthor with Clark on the CSBA fleet-architecture study, added that “Distributed Lethality,” the surface fleet’s new doctrine for a more offensive posture, “succeeds or fails on the strength of the logistics that support it. If a ship has to head back to a selected port to reload, it is out of action for an unacceptable period of time.”
“A Ship Is a Building When Sitting next to the Pier”
These issues are perhaps nowhere more salient than in the Western Pacific, where the United States now finds itself facing down a peer competitor for the first time since the Cold War. While China's People’s Liberation Army (PLA) can concentrate its entire naval strength in its own home waters under the protective umbrella of aircraft and missile artillery based ashore in China’s continental interior, the Navy can only allocate a portion of its globally dispersed force to East Asia, and is further hamstrung by the more than six thousand sea miles that separate its fleet concentration areas in the Continental United States from the potential combat theater along the First Island Chain. James Holmes, professor of Strategy and Policy at the U.S. Naval War College and one of the preeminent voices on American maritime strategy with respect to an ascendant China, considers the current dependence of VLS-equipped warships on shore installations in the context of the susceptibility of forward bases and the ships docked there to Chinese missiles. For Holmes, “The bottom line is that we must be able to regenerate combat power, and we can't count on reloading missiles pierside in places like Yokosuka, relatively close to the theater. A ship is a building when sitting next to a pier, and thus is exceedingly vulnerable to ballistic missile and other area-denial weaponry.” Regarding concerns about anti-ship ballistic missiles being able to strike ships at sea as well as in port, Holmes added, “There is some debate about whether China can detect, track and target surface ships far offshore in order to vector in DF-26s or what-not. There is no debate at all about whether the Strategic Rocket Force, PLA Air Force, or PLA Navy can range Yokosuka. Guam, the next closest place to the theater, would be under the PLA's shadow as well.”
In a potential conflict, Chinese forces could incapacitate U.S. and allied bases in-theater, and then exploit VLS warships’ shallow magazines and immobile logistics chain to put them out of the fight, regardless of whether the vessels themselves are actually destroyed. Holmes explained the dynamics of such a maneuver, where “anti-ship strikes at sea could deplete our defensive missile arsenal, even if the PLA scores no hits. That means the carrier task force or surface action group would have to take vessels off the line for days or even weeks, depending on where they went to rearm. They might have to cruise thousands of miles to do so.” By Holmes’s calculation, “Debilitating U.S. Navy combat power without a fleet engagement would constitute a win for Chinese defenders. It's a mission kill on a VLS-equipped ship for the length of time that ship is away.”
Underway Replenishment or “Forward Reloading?”
It remains unclear what specifically CNO Richardson and the Navy have in mind for “bringing back” the ability to reload vertical launch cells at sea (Admiral Richardson’s Public Affairs Officer did not respond to an email requesting clarification before publication). Early Ticonderoga-class cruisers and Arleigh Burke-class destroyers once had VLS strikedown cranes that were rated to lift medium-range SM-2 surface-to-air missiles and ASROC antisubmarine rocket-boosted torpedoes, but were incapable of lifting larger loads of the size of Tomahawk cruise missiles and the new multipurpose SM-6. The cranes were left off the newer Flight IIA Arleigh Burkes to make room for additional VLS cells. A 2009 study by Marvin O. Miller of the American Society of Naval Engineers demonstrated in tests ashore the potential feasibility of a robotic VLS reloading arm, stored and maintained aboard a logistics ship, that would do away with the more precarious block and tackle system of the legacy strikedown crane.
Neither Holmes nor Clark believe that the Navy’s new reloading capability will take the form of underway replenishment, in which a logistics vessel steams alongside a combatant at 12–13 knots and transfers supplies and fuel over a high wire between them. Rather, both advocate for a doctrine of forward reloading, where combatant and logistics ships meet in protected harbors close to the contested zone and replenish missiles either at anchor or while holding position under power, as was done off Oman’s Masirah Island in 1991. Holmes, who served as a Surface Warfare Officer before transitioning to academia and was, in fact, the last gunnery officer to fire a battleship’s big guns in anger aboard USS Wisconsin during Operation Desert Storm, elaborated on the technical challenges associated with replenishing missiles underway, and how they would likely influence operational and strategic practice toward the anchorage-based model. “We must rediscover how to rearm close to the combat theater, and that probably means improvising weapons depots in the Western Pacific. It probably cannot be done during alongside operations. We can transfer gun projectiles and suchlike by high wire when alongside an ammunition ship, but, say, an SM-6 or Tomahawk is simply too big to do it safely. We might well damage the missile or the VLS cell. We need calm seas to do it. This would be one time when a nice calm lee would be a help—hence the value of geographic features like islands and atolls.”
Clark suggested that even legacy systems like versions of the strikedown crane would still be useful under this adapted construct of forward reloading at anchor. “Ships today can replenish weapons at sea, but they cannot easily reload weapons into their VLS magazines outside of port. Systems that have been developed for at-sea reloading tend to not work well in even moderate sea states. If the Navy put these systems back on ships, however, ships could reload in a calm location closer to the fight, such as an island or atoll, rather than having to go all the way back to a secure port. That could save weeks of transit time and enable them to get back on the front line faster. We advocated these systems be put back on to ships in our fleet architecture study earlier this year.”