Surface to Air Missiles... As Antiship Weapons

While the United States Navy has never fully embraced the concept of the dedicated antiship missile, adopting and then abandoning a number of systems, that does not mean that its missile ships have even been defenseless against surface attack. In fact, even its earliest converted missile cruisers possessed greater antiship firepower than a World War II battleship.

Surface to Air Missiles in Surface to Surface Mode

The secret behind this is the use of surface to air missiles in surface to surface mode. Until the introduction of the infrared homing Rolling Airframe Missile in the early 1990's, all of the Navy's surface launched antiaircraft missiles have been semiactive radar homing. This means that as long as the ship mounted illumination radars can get a clear reflection off the target, the target can be engaged - even if it's a ship instead of an airplane (while this means that ships cannot be engaged from over the horizon, there has never actually been a successful over the horizon surface launched antiship missile attack).

The first indication of the Navy's intent to use its new missiles against surface ships can be seen in the fate of the escort carrier USS Makassar Strait (CVE-91). In 1958, after spending over a decade in the reserve fleet after WWII, Makassar Strait was anchored as a target off California to test the effects of the Terrier and Talos missiles that were then entering the fleet.

USS Makassar Strait (CVE-91) aground in 1963 after serving as a missile target.

Battleship Guns vs Surface to Air Missiles

While some may consider this use of a surface to air missile an emergency capability at best, a quick look at the numbers shows this to be a serious error. An early Terrier missile weighed half a ton (not counting its booster), traveled at Mach 3, carried a 200 pound fragmentation warhead, and had a range of 20 miles. In comparison, a High Capacity shell from the famed 16" guns of an Iowa-class battleship weighed one ton, traveled at Mach 2, had 150 pound bursting charge, and a range of 20 miles.

While the 16" shell was twice the weight of the missile, it's lower speed and smaller bursting charge meant that it actually delivered some 20% less energy than a Terrier. When compared to the 1.5 ton Talos missile with its 300 pound warhead and 50 mile range (over 100 miles on later variants), the 16" gun didn't stand a chance, delivering only half the energy of the powerful ramjet and having half the range to boot (interestingly, while Talos required terminal illumination for aimed shots, the system could use its beam riding capabilities to loft unguided missiles out to their maximum ballistic range - this was tested against land targets and found to be reasonably accurate out to around 40 miles).

Of course, comparing missiles and shells one for one is somewhat comparing apples and oranges. After all, an Iowa-class battleship mounted no fewer than nine 16" guns, each supplied with 130 rounds and capable of firing 2 rounds every minute. Against such firepower an early and relatively slow firing guided missile ship such as USS Boston (CAG-1) couldn't stand a chance... Right?

Unfortunately, Iowa was let down by her unguided projectiles. Even at Mach 2 it takes nearly a minute for a shell to travel 20 miles and in that time a 30 knot target can travel several times its own length. While Iowa possessed the best gun fire control system of her day, even the most advanced computers cannot predict random maneuvers. Thus, the battleship would be lucky to achieve even 5% accuracy against distant targets and her 18 shells per a minute rate of fire becomes just 1 hit a minute at best (and in practice, naval gunfire almost never close to reaching its theoretical maximum rate of fire).

In comparison, just one of the two Terrier launchers aboard Boston could fire 4 missile every minute and reasonably expect to hit with all of them. Even taking into account the rather poor reliability of early missile systems and assuming that 25% of the Terriers fail for various reasons, Boston is still scoring hits at six times the rate of Iowa and each hit is just as damaging. While Terrier lacked the armor piercing capabilities of the 16" gun, when Boston became operational in 1956 there were only 6 battleships in service - 3 American, 2 French, and 1 Italian - and the most likely surface targets were Soviet light cruisers.

Even in terms of sustained battle Iowa is at best equal to Boston. While the battleship carried nearly 1200 shells for its main guns, even allowing for engagements at medium range where 10% accuracy could be expected, that is enough for only 60-120 hits. However, even in the face of such unimaginable firepower Boston keeps up, carrying no fewer than 144 Terrier missiles - over 100 hits at the somewhat pessimistic 75% accuracy assumed above.

Real-World Results

While Terrier and Talos themselves were never employed against hostile ships, the destructive effect of surface to air missiles employed against ships is far from theoretical. During the 1988 Operation Praying Mantis, the Iranian missile boat Joshan was destroyed by US Navy ships firing Standard surface to air missiles at a range of 13 miles. While the two Harpoon antiship missiles fired during this engagement (one American and one Iranian) both missed their targets, all four (or five depending on the account) SM-1 missiles hit, wrecking Joshan, setting her on fire, and forcing her crew to abandon ship.

1992 saw further, if inadvertent, demonstration of this effectiveness when the aircraft carrier USS Saratoga (CV-60) accidentally fired two Sea Sparrow missiles at the Turkish Allen M Sumner-class destroyer Muavenet during an exercise. Both missiles struck the 2000 ton ship at a range of 3 miles and, despite each having only a third the energy of a Terrier, wrecked her bridge, set her on fire, killed 5 sailors including her commander, and wounded 22 more.

Turkish destroyer Muavenet after the 1992 incident.

Given how effective Talos, Terrier, and Tarter were against surface targets (even before considering the fact that the first two were both deployed with nuclear warheads!), the US Navy's decision not to seriously pursue the dedicated antiship missiles that were pioneered by the Soviets begins to make considerably more sense.

Today, we stand at the beginning of what is shaping up to be another attempt by the US Navy to field antiship missiles. Currently the Long Range Antiship Missile (LRASM), the Naval Strike Missile (NSM), the Surface to Surface Missile Module (SSMM), and the Maritime Strike Tomahawk (MST) are all on the verge of entering service. However, judging by history, it is just as likely that these programs will eventually wither away while surface to air missiles remain - especially now that the active radar homing SM-6 allows a surface to air missile to engage ships from over the horizon.