UNITED24 - Make a charitable donation in support of Ukraine!


CG Guided Missile Cruiser

With the emergence of air power as the trump card in American military strategy, and the "revolt of the admirals" having been put down, naval carrier task forces assumed a tactical role equivalent to battleships in Mahan's classical doctrine. Both in blue water operations and in power projection missions where air strikes would be launched from the carrier against shore targets, there was an important anti-air warfare (AAW) role for screening ships to protect the carrier from enemy air attacks. Naturally, a carrier could launch short range fighters to provide air cover, but not in all weather conditions in which shore based aircraft could attack. In World War II it became clear that a carrier group needed a deeper defense with surface ships equipped with radar and AAW weapons spread out around the carrier.

During this period the U.S. Navy also recognized the need to respond to new technology, the anti-ship missile and faster aircraft. During the summer of 1943 the Germans introduced the FX-1400 air-launched, radio-controlled anti-ship missile. These missiles weighed about 3,000 pounds and when launched from the correct height could attain a terminal velocity of 800 feet per second, similar to an artillery shell. On 9 September 1943, the Italian Fleet was on its way to surrender to the Allies in Malta when one of Italy's newest battleships, Roma, was hit with one of these missiles that caused one of the forward main gun magazines to explode. The battleship broke in two and sank. Another exploded alongside the new battleship Littorio, damaging its shell plating. During the invasion of Salerno the U.S. light cruiser Savannah was struck by one of these missiles on 11 September 1943. Although the missile exploded in the magazines of No. 3 turret, inrushing water prevented further explosions. On 16 September 1943 the British battleship Warspite was hit by two missiles off Salerno, one that passed through all decks, including the armor deck, and through Boiler Room No. 4, finally exploding in the double bottom. This caused severe damage to the under bottom structure. A second bomb exploded in the water alongside Boiler Room No. 5, causing damage to the shell plating.

Experience of Kamikaze attacks in World War II showed that for an airplane diving into a ship with the intention of crashing, an attack profile that resembled a guided missile's, hitting it with the short range AA guns of the period was not enough. The 40-mm Bofors mounts had an effective range of 2,500 to 3,000 yards. The 20-mm Oerlikon was effective against aircraft at less than 1,000 yards. A direct hit from a 20 or 40-mm shell caused the kamikaze to break up, but the pieces continued on in a ballistic trajectory along with the burning fuel to hit the defending ship. Even within this limited range, the majority of shells fired would still miss their intended target; 400 to 500 rounds of 40-mm was needed to achieve a kill. It was necessary to hit the attacking aircraft when it was further away from the ship than the effective range of these smaller weapons of World War II. The 5-inch 38 had an effective range of 7,000 to 10,000 yards, and it could reliably stop a Kamikaze before it entered its final dive. Its effectiveness increased by about a factor of five when the Variable Time/proximity (VT) fuse was introduced.

The Japanese were also working on a "Baka" bomb, a manned suicide missile patterned on the German V-1 that because of its higher speed represented even a greater threat. This combat experience drove the development of a number of new AA weapons that came into use in the postwar period. One was the 3"/50 gun, chosen both for its longer effective range compared to the 40-mm guns it replaced and for its ability to carry the VT fuse.

Towards the end of World War II, in both theaters of the war, serious airborne threats appeared. In the European theater, the Germans deployed guided glider bombs (previously mentioned) that made it possible for a bomber to attack a ship without coming very close to it. In the Pacific, the Japanese Kamikazes showed how much damage a guided missile could do if it hit a ship, as well as how much harder it was to shoot down the attackers compared to conventional bombers. Since an aircraft carrier, especially in that time period when instrument flight was in its infancy and the carriers were much smaller than they are today, might under some weather conditions be unable to launch fighters, AAW capability in the surface screen was essential. And with the new stand-off threat coupled with the indifferent performance of the 6-inch/47 automatic gun, it was evident well before 1950 that surface to air missiles were one promising answer. Surface to surface missiles were also shown to be effective by experience with the German V-1 and V-2.

By 1944, a "Project Bumblebee" existed at the Applied Physics Lab (APL), to develop a ramjet-powered surface to air missile (SAM), eventually to see production as the Talos. Rear Adm. H. G. Bowen, who also had had a role in the 600-psi steam plant development before the war, headed the Navy's R & D office in the postwar period. He recognized that SAM's would require extensive ship volume to deploy. Destroyers of the time were too small, battleships had more weight-carrying capacity than cruisers without so much more enclosed volume. Cruisers seemed adequate to the task and, more important, there were a large number of them that were no longer needed for traditional cruiser missions with the disappearance of an enemy surface fleet. Battleship conversions would also have involved removal of some heavy armor to provide large enough spaces for missile handling; this would compromise survivability. By 1955-6, the Terrier missile would be ready to enter service after a high priority development program at APL and the Navy Research Lab (NRL).

A very serious drawback to the whole concept of a SAM was (and is) that in order for the missile to find its target, an incoming aircraft at first and later an incoming missile that could be much smaller, it was necessary to have a long range, high accuracy radar to find the target far enough away to give time to achieve a firing solution. Also, a fire control radar (that could be the same device) had to track the SAM and the target during the flight of the SAM and either give the latter command guidance, or provide enough information that the SAM's warhead could calculate interception courses and guide itself to the target. This led to enormous demands for complexity in the ship's electronic installation, and also to substantial electronic "smarts" in the missile itself, so that a small weapon could not contain the necessary equipment. The large size of the warhead dictated rather a big missile, with dire results in terms of high cost and large volumes required to install it in a ship. Needless to say, there's only so much complexity that can be put into something that will only be used once. And as hardware evolved, it became apparent that early SAM's were not very accurate or reliable.

One of the most significant developments in post-World War II cruiser design were the rapid advancements in electronics, both radar and sonar, that would be able to detect threats at longer ranges than had been possible in World War II. The growth in electronic equipment had significant effects on ship size, configuration, powering, and cost. All of the electronics and weapons had to be controlled by the ship's Command and Control system. This greatly increased the volume of electronic spaces for communications, computers, and control equipment, particularly in the Combat Information Center (CIC). This was important because with the increased speeds of the submarine, small missile boats, missiles, and aircraft, targets had to be identified at greater distances from the ship. This also required correct placement of this equipment and antennas to minimize interference with each other.

The radiation emitted by these more powerful radars presented an increased hazard to personnel, restricting the admissible locations of the antennas and complicating superstructure and mast arrangements. All of these topside electronic devices, guided missile installations, and the larger superstructures to support and house them resulted in higher vertical centers of gravity, affecting stability of the ship. Therefore, aluminum superstructures were used in cruisers, destroyers, and frigates to reduce topside weight. Topside weight also tended to lead to larger beam, changing the proportions of the ships.

Join the GlobalSecurity.org mailing list

Page last modified: 07-07-2011 12:42:01 ZULU