Why Such Small Warheads; USN Missile Edition

In an earlier post, I commented on the lack of punch of a SM-6 when used against a warship. While the idea of using a five-million-plus dollar missile to deliver the equivalent of a 250lb bomb may sound deplorable, there is a good reason why the navy got away from ship-killing surface weapons.

The reason, simply put, was the lack of a good reason to have them. In a "cold war gone hot" scenario, it was pretty well assumed that, between airpower and submarines, any larger combatants of the Soviet navy would have either fled into port or been swept from the sea in the first day or so of the war. The role of the navy would then be to open and keep open the sea lines to Europe, as was done in the Battles of the Atlantic during both world wars. Besides hunting down and sinking Soviet submarines, the navy would have had to combat the threat posed by Soviet antiship missiles, whether air-launched or submarine-launched. So antiair and antisubmarine warfare were the predominant training tasks of the Cold-War navy.

Antisurface, or ship-on-ship warfare, was given short shrift. The 5" guns of the destroyers and frigates had two missions: Antiair defense of the ship and naval gunfire support for forces ashore.

Then two things happened: The sinking of the INS Eilat by Egyptian missile boats and the use of missile boats in the 1971 Indo-Pakistani War.

The first thing that was done was to quickly give the Standard missile a surface-to-surface capability. That was called "ISSM": "Interim Surface to Surface Missile". Some were fitted into two of the cells of an ASROC box launcher to give some non-AAW missile shooters a modest capability to fire anti-surface missiles (which required modifying the fire control radar to work with the missiles).

Meanwhile, the Harpoon missile, which was first designed for use against surfaced submarines (some Soviet subs had to surface to fire their missiles) was quickly reassigned a role as an antiship missile. Once Harpoon was out in the fleet, ISSM was rapidly retired (and quickly forgotten).

Still, the threat that Harpoon was redesigned to engage was the threat of missile boats employed by Soviet client states or Warsaw Pact nations. It wasn't really considered as a weapon against larger ships. Because at the time, nobody could foresee a use against large combatants.

The Soviet navy built bigger missiles, with half-ton or larger warheads, many supposedly with shaped-charges (if you can believe Wikipedia). They were built to sink or cripple large ocean-going ships, like carriers, which Western navies operate. Even if a point defense system detonated its warhead, a shaped charge that was detonated a few hundred yards away from a ship could probably do some serious damage.

This far into the 21st Century, there still isn't much of a use for a large antiship missile by the navy, at least not launched from ships. The aviators have been working the problem, the Long Range ASM is projected to carry a half-ton warhead. Which is probably realistic, in that our ships aren't going to be operating in the western Pacific without some form of air cover.

Still, I wouldn't be surprised if there were at least studies on a new heavy antiship missile for employment by surface ships. I would be surprised if anything more than that had been done. Adding a large weapon system to a ship is not a trivial modification- the mounting of quad-tube Harpoon launchers on the Cold War CGs and DDGs raised issues of stability in heavy seas (as does adding anything heavy that far above the center of gravity).

The addition of a heavy antiship missile to the surface fleet may have to wait for the development of a new class of surface ships. Which, to my mind, will not happen within the lifetimes of most readers of this blog.