Judging the Good from the Bad

By Norman Friedman

Cruisers saw a lot of action in both navies. In the late 1930s, the U.S. and Royal navies built small cruisers armed with dual-purpose guns: the American Atlantas and the British Didos . Both classes were often called antiaircraft cruisers, but neither really was. They were both conceived mainly to work with groups of destroyers, backing them against the heavy ships the destroyers were expected to attack. The British were far more obsessed than Americans with limiting the cruisers’ size, which they equated to the ships’ cost, and they also selected a heavier, 5.25-inch dual-purpose gun, rather than the U.S. 5-inch gun.

Both classes were well liked in wartime, but the British clearly found the Dido s too small and too tight. Late in the war they nearly opted for a new class of ships with similar main batteries—but enlarged from the former ships’ 5,500 tons to more than to 8,000 tons, which says a lot about how successful the small Dido s really were.

The relatively heavy 5.25-inch gun was chosen for secondary batteries on battleships mainly because it had the punch to stop an enemy destroyer approaching to attack with torpedoes, not because it could be fired quickly against attacking aircraft. It fired much more slowly than the U.S. Navy’s 5-inch/38-caliber gun.

In fact the British found the 5.25-inch guns so heavy and poorly adapted to antiaircraft fire that their carriers instead were armed with 4.5-inch guns, which were considered antiaircraft weapons. Their cruisers had 4-inch antiaircraft guns. The combination of small ship size and heavy gun was so unfortunate that repeat Dido -class cruisers built during the war sacrificed one of their five twin 5.25s. Indeed, most British cruisers of this period gave up one turret for a more powerful antiaircraft armament, which left them with half the secondary battery of a battleship.

In both cases the sacrifice bought light antiaircraft guns, which were intended mainly to defend the cruisers against aircraft heading for them, rather than to contribute to the area defense of a formation. Presumably one measure of the value of an antiaircraft ship was the ratio of heavy antiaircraft weapons, which would help defend other ships, to the light weapons needed for the ship to survive.

The U.S. Atlanta -class light cruisers displaced about 6,000 tons. As conceived, they had substantially less light-antiaircraft firepower than the Dido s, and they too had to sacrifice heavy guns to provide enough light guns to protect themselves. They were designed with eight twin 5-inch/38-caliber mounts, two of which (the worst-placed ones on the ships) were removed. That left as many 5-inch antiaircraft guns as on board any of the U.S. cruisers that helped protect carriers. Instead of backing destroyer attacks, the Atlantas found themselves, along with other new U.S. surface warships, covering the carriers that now provided the Pacific Fleet’s main offensive punch.

The Atlanta -class cruisers had enough reserve of stability to accept a very heavy self-defense battery plus a full radar outfit, which was badly needed in their new role. The Atlanta s were both lucky (they featured the best dual-purpose gun of the war, and an excellent fire-control system to boot) and large enough to make use of that luck. The U.S. Navy showed its satisfaction with the ships by building modified Atlanta -class cruisers during the war and by choosing enlarged Atlanta s (with new 5-inch/54-caliber guns) as the last cruisers it ordered during the conflict.

Why did the Atlanta cruisers succeed where the Dido s probably did not? Larger size made them more adaptable to the new kind of war the U.S. Navy fought in the Pacific (quite aside from the fact that a far better power plant gave them the range they needed). The ships were not so large that they could easily be adapted to the new postwar technology, although they were seriously considered for some conversions. In contrast, the one attempt to modernize the Dido s with new guns was abandoned when it turned out that the ships would not have the space for more than a minute or so of fire from the weapons.

Essex vs. Illustrious

There’s a consistent pattern to the run of U.S. and British warships. British designers were proud of holding down the size of their ships, whether or not they were forced to do so by prewar treaty obligations. They clearly equated size with cost, and the designers understood that more ships is better, which is certainly true.

But British design records contain no suggestion that technology might be changing in a direction that would demand larger ships. That is particularly difficult to understand in the case of aircraft carriers; by the 1930s it must have been obvious that airplanes were changing rapidly. U.S. carrier designers were lucky because they began work on the main wartime U.S. carriers, the Essex class, after the outbreak of war in Europe had ended the naval-treaty system that limited size.

The masterpiece of British carrier design was the armored-deck Illustrious . Carrier designers were always aware that a flattop was a disaster waiting to happen, and the most obvious way for a major mishap to occur would be for the enemy to put bombs through the flight deck. The Illustrious actually had an armored hangar rather than a completely armored flight deck, but even her limited amount of deck armor made a great difference—particularly in the face of kamikazes at the end of the war.

As with the case of the Dido s, there was a key “but.” When the Illustrious was designed in 1936, the Royal Navy dismissed the possibility that carrier fighters could beat off bombers (visual warning time was too short). It was willing to settle for the limited number of strike aircraft that could be stowed in a relatively small, closed, protected hangar. Part of the price paid was reduced freeboard (seakeeping) and a shorter, slower hull.

Ironically, just as the ship was being designed, the first radars were being tested; they held the promise that carrier fighters might be able to defend carriers—and therefore that the ships should have much larger air groups. When that became obvious, the latter ships of the Illustrious class were redesigned with double hangars, but the price included such low overhead clearance that later aircraft were difficult or impossible to stow. That did not make for a great postwar future.

The U.S. Navy built the larger Essex -class carriers that had unarmored, open hangars but armored hangar decks, which made them very difficult to sink, whatever happened to their flight decks. The most important difference was that the American carriers accommodated air wings that were nearly three times the size of those on board British carriers, and large air wings perfectly fit the new kind of warfare being waged in the Pacific. Plus, the open hangar made the ships relatively easy to modernize postwar. Despite plans to update all of their six wartime fleet carriers, the British modernized just one because they soon realized that the work would be (as it was) a drawn-out nightmare, due in part to the armored hangars.

The U.S. Navy never would have been able to prosecute the Pacific war had it relied on small British-type carriers. In 1941, when they first saw HMS Illustrious , U.S. officers were very impressed and wanted armored flight decks. They finally got them in the Midway s—but that was because the Navy was willing to build 45,000-ton carriers rather than the 27,000 tons of an Essex or the 23,000 tons of an Illustrious .

Size bought the flexibility for some Essex-class carriers to remain in the front line of naval aviation through the early 1970s as the airplanes on board drastically changed. In 1939, for example, a typical attack bomber might weigh 12,000 pounds, but by 1960 the A3D weighed about 70,000 pounds.

The fact that size mattered a great deal was not really a new lesson. After the Washington Naval Conference of 1921, the U.S. Navy decided to convert two incomplete battle cruisers into the carriers Lexington (CV-2) and Saratoga (CV-3). These huge ships were so large that by the mid-1920s, well before they could be completed, they were being derided as white elephants. Analysis at the Naval War College seemed to show that it would be far better to build numerous smaller carriers, because together they would have greater flight-deck area and hence greater total aircraft capacity. The USS Ranger (CV-4) was designed and built on this basis.

While the Ranger was being constructed, the two white elephants entered service and demonstrated that size mattered. In this case, it was soon obvious that the total number of aircraft in a fleet was not as important as the number on board each carrier, because the latter comprised U.S. carrier aviation’s tactical unit, the air wing. (Later, well into World War II, the U.S. Navy began conducting multicarrier air-group operations.) Size also bought speed and survivability. The Lexington and Saratoga , but not the Ranger , fought in the Pacific. The bigger carriers were not turkeys; they were ugly ducklings that became swans.

Many of the ships the U.S. Navy built during World War II reinforce the bigger-is-better lesson. Designers always want to create the tightest possible package that fulfills specific requirements. For various reasons, by 1941 the U.S. Navy was demanding enough to get larger packages than those of some other navies (German heavy cruisers and destroyers were larger, apparently without getting as much for the tonnage). During the war, British captains periodically wrote that they wished they could have similarly large ships, and by the time Japan surrendered the British were designing and building U.S.-size destroyers. However, the usual response by the British design authority was that the American ships were large simply because their designers were incompetent; they produced loose, expensive ships.

The naval world changed during the war, as conflict in the Pacific increasingly became carrier warfare. It changed even more postwar, largely through the introduction of new technologies such as missiles, jet aircraft, and heavy electronics. For the U.S. Navy, the changes were affordable largely because its wartime carriers, cruisers, destroyers, and submarines were so large that they were adaptable. They were probably never seen as turkeys, but they were certainly swans in retrospect.

The only real criticism was that having been designed mainly for the calm Pacific, the ships were ill-adapted to patrolling rough northern waters, which Cold War service usually entailed. The British had much better hull forms for seakeeping. However, many of their well-designed warships could not accommodate new technologies, resulting in the size of the Royal Navy contracting faster than necessary.

For example, both navies embarked on development of surface-to-air missiles in 1944. The American missiles were the Terrier and Talos; the British was the Seaslug. The U.S. Navy managed to field the Terrier relatively quickly because it could be installed aboard two heavy cruisers, the Boston (CA-69) and Canberra (CA-70). The British could not even imagine quickly fielding the Seaslug because their cruisers were too small. They nearly lost the opportunity to field it altogether because they thought it was necessary to build a massive new cruiser for the purpose. It took First Sea Lord Louis Mountbatten to insist that the missile could be squeezed aboard a big destroyer, and that squeezing took enormous ingenuity.

Postwar Destroyers and Frigates

Perhaps the greatest recent transformation from ugly duckling to swan were the U.S. Spruance -class destroyers, only recently decommissioned. When completed, the Spruance s seemed to be cruiser-size ships with frigate armaments—a ludicrous combination. They were so large because plans originally called for a single ship that could be completed as either a missile (antiaircraft) destroyer or an antisubmarine destroyer (essentially the missile destroyer with missiles removed). Doing that was less expensive than building two separate classes.

But the program was halted before the missile destroyers could be built. The only Spruance -class missile destroyers were four ships laid down for the shah of Iran and then taken over by the U.S. Navy as the Kidd -class destroyers. The sheer size of the Spruance hull, however, permitted the addition of considerable weaponry that could not possibly have fit into a smaller ship.

The first sign that the big Spruance hull was well worthwhile was that it could be adapted to take the Aegis missile system—as Ticonderoga -class cruisers. That mattered enormously. At the time it was the only economical way to put Aegis to sea, the alternative being a larger and unaffordable nuclear cruiser. Score one for the ugly duckling. Similarly, the antisubmarine launcher forward in the Spruance -class destroyers could be replaced by 64 vertical cells, each carrying a Tomahawk land-attack missile. By the time they were retired, the Spruance s were valued as general-purpose destroyers with substantial land-attack firepower, a role that carried over into the later Zumwalt class, conceived to replace them.

The surface combatants the U.S. Navy built to succeed the Spruance s almost might be considered an experiment in tight vs. loose design. The Oliver Hazard Perry –class frigates were deliberately cost-controlled, largely by limiting their size. They were mainly intended to fill an air-defense gap, and to pay for that capability they sacrificed the sort of long-range sonar with which Spruance s were equipped.

The frigates were useful in a Cold War context, but life is unpredictable. When the Perry s were conceived in 1971, the Cold War seemed to be a fixed fact of life. Twenty years later it was over. Most NATO navies had concentrated on Cold War tasks: antisubmarine warfare and defensive mine countermeasures. With the end of that conflict, neither was nearly as important.

The U.S. Navy discarded its specialized convoy escorts, mainly Knox -class frigates, and it soon abandoned most of the Perry s. Surviving ones had their missile system, for which so much had been sacrificed at their outset, removed because it was considered ineffective against current “pop-up” threats. If this article had been written in 1980, the Perry s and the Knox es would have been swans. Now they look more like turkeys. The big U.S. destroyers and cruisers look like the real swans, because they were conceived for the type of strike warfare the U.S. Navy espoused in the 1980s. Size pays.

The Allure of Speed

At the other end of the spectrum, both during World War II and in the 1970s the U.S. Navy invested in small, fast combatants: respectively, PT boats and missile hydrofoils (PHMs). In each case speed was an overriding virtue, the theory being that a really fast ship could dart out, strike, and escape before an enemy could return fire. Many other navies thought the same way before and after World War II. The Soviets and their Chinese pupils, for example, built flocks of fast torpedo and missile boats. Swans or turkeys?

The U.S. Navy got remarkably little out of its big PT fleet in World War II, and it discarded nearly all the boats immediately afterward. The official verdict was that they had been nearly useless. They had effectively interdicted Japanese barge traffic in the Solomons, but that task did not require the speed built into them, which resulted in the boats being flimsy and relatively dangerous. On other occasions, as in the Philippines, they failed to hit their major combatant targets, perhaps because firing effectively from a small, bouncing boat is rather difficult.

As for the PHMs, only 6 of a planned 30 were built, and they were discarded at about midlife. More tellingly, foreign buyers could not be found. The PHMs incorporated a revolutionary form of foil control that made it possible for them to operate and maintain speed in far rougher weather than simpler hydrofoils. The craft should therefore have been rather attractive. Moreover, Boeing, which had built the PHMs and owned rights to their technology, could not find any buyers for somewhat comparable hydrofoils; no one in the West really needed very high speed.

That should not have been a great surprise. High speed always has been very attractive, but those interested rarely if ever appreciate how much it costs—and not just in money. Before World War II, the French and the Italians competed in building ultrafast destroyers, to the extent that builders advertised trial speeds in successive editions of Jane’s Fighting Ships .

In 1945 the French liaison officer with the U.S. Pacific Fleet wrote that the effort had been pointless. High-powered machinery was too delicate, consumed too much space, and required too much fuel. Tactically, it bought nothing. The French naval staff listened and then abandoned the search for high speed in the postwar Surcouf -class destroyers. Once aircraft became the core of fleets, warships only needed enough speed to keep up with carriers. No ship could be fast enough to evade an attacking plane or helicopter.

Value of Size in Subs

Submarines are a special case. They are particularly difficult to design because their underwater volume must exactly balance their weight. Perhaps the most successful U.S. subs were the “fleet boats” of World War II. They were extremely effective in their design role: destroying the enemy’s merchant fleet while scouting for the U.S. Fleet. Probably no smaller submarine would have done as well.

The fleet boats also met the standard implied in this article: flexibility in the face of dramatically changing context and technology. They proved well suited to modernization (fleet snorkel and Guppy programs) and also to completely new roles, such as serving as radar pickets and strategic missile carriers. In the process, they validated the U.S. Navy’s view that size was well worthwhile. At the time, other navies derided the fleet boats for their size. The British, for example, opted for more economical submarines. They may have performed better in constricted European waters, although even that is not certain.

Evaluating more modern submarines is difficult; however, the lesson generally has been that size pays. The least successful nuclear submarines were the ones drastically cut down to reduce their costs: the Tullibee (SSN-597) and the Skate s. The best of the lot were probably the Los Angeles class, because they had the most “stretch” in them. This included the ability to add Tomahawk missiles. It seems unlikely that any earlier, more tightly designed submarines could have accommodated a substantial number of unmanned underwater vehicles—again, an important role unimagined when the submarines were designed.

Many observers had derided the Los Angeles (SSN-688) as too large, her design governed by Admiral Hyman Rickover’s atavistic insistence that to increase speed she should have a massive new power plant rather than a much more efficient hydrodynamic hull and a less powerful power plant. Greater hull size probably encouraged other improvements, which might have been difficult to shoehorn into the more compact hull that many had preferred.

The Lessons of Ship Design

What conclusions can be drawn about ship design? One lesson, at least in surface ships, is that reaching for spectacular performance, speed for example, is often counterproductive: The enemy’s weapons generally outrun ships. The sacrifices made for a few knots may be difficult to identify, but they are real and later on become unacceptable. Also size pays, even if at the outset it may seem wasteful. The larger the ship, the better the opportunity to modernize her to keep up with a changing world.

A navy needs numbers. Usually that is translated to mean that ships should be made as inexpensively as possible. However, there is another way to look at numbers.

The number of ships the U.S. Navy can maintain is, roughly, the number the Navy can build each year multiplied by the number of years a ship remains viable—and viability is a matter both of how well the ship survives the rigors of the sea and of how well she survives the rigors of a rapidly changing world. The bigger the ship, the better she will survive the sea. If bigger also means better at adapting to the changing world, the answer to numbers is probably to build fewer ships each year but to make them big.

This may seem somewhat simplistic. For example, large ships require large crews, and building fewer ships each year makes it more difficult to replace those lost in action. But the overall lesson remains. The only real caveat is that the fundamentals of hull design and machinery not change radically. If they do, if a particular hull or power plant becomes obsolete, then it does not matter how long the ship can last.

That has happened. Around 1860 the Royal Navy had an enormous lead over other navies in capital ships. Its large number of wooden “liners” lasted a long time in reserve, and they could be updated with steam propulsion. Then the French introduced armor. All those unarmored wooden hulls were suddenly obsolete. The British armored some of their wooden capital ships but concentrated on new iron hulls, which were far more satisfactory. The race to rebuild British naval superiority was horribly expensive, and the British felt compelled to cancel large numbers of projected wooden cruisers to buy enough iron battleships.

More recently the demise, or near demise, of diesel-electric submarines in favor of nuclear submarines had much the same impact on the U.S. Navy. It dramatically reduced the value of submarine capital, represented by the service’s large post–World War II supply of fleet boats, before the diesel subs would have been discarded due to age.



A note on sources:

This article reflects my long experience writing ship-design histories based on official papers from archives, mainly in the United States and the United Kingdom. I also have used French archives at Vincennes, but I have not compiled design histories comparable to those of U.S. and British ships (the comments by the French liaison officer in this article are from the records of the Conseil Superieur de la Marine, comparable to the U.S. General Board).

For details, see my Illustrated Design History series on American warships, all published by the Naval Institute Press: U.S. Aircraft Carriers (1983); U.S. Battleships (1985); U.S. Cruisers (1984); U.S. Destroyers (1982, 2003 revised edition covers the Arleigh Burke s, Zumwalt , and LCS); U.S. Submarines through 1945 (1995); U.S. Submarines since 1945 (1994); U.S. Small Combatants (1987); and U.S. Amphibious Ships and Craft (2002). No volumes on minecraft or the fleet train have been published, although I have done extensive research in both categories.

For the Royal Navy, I have published a history of aircraft carriers and their aircraft ( British Carrier Aviation: The Evolution of the Ships and Their Aircraft , Naval Institute Press, 1987); a history of later British cruisers ( British Cruisers: Two World Wars and After , Naval Institute Press, 2010); and two volumes on British destroyers ( British Destroyers and Frigates: The Second World War and After , Chatham, 2006; and British Destroyers: From Earliest Days to the Second World War , Naval Institute Press, 2009). A book on earlier British cruisers, scheduled for release this fall, is the source of my comment on the 1860 situation. I also have researched British battleships and British submarines, perhaps for later publication.


How Can You Tell?

By Norman Friedman

According to an old proverb, “to understand all is to forgive all.” The more you know about how and why ships were designed, the more difficult it is to dismiss them as disasters. It is also difficult to be sure how successful some ships actually were. Knowing how many of a particular design were built doesn’t help. When a country mobilizes, it tries to mass-produce whatever is then being built.

The U.S. Navy ended up with 175 Fletchers because that was the U.S. destroyer class in production in 1941—and the Fletchers happened to be an excellent design. The Navy ended up with a lot of “flush-deckers” because that destroyer design was in production in 1917—and, because its designers mistakenly denigrated the value of a forecastle, the ships were not so excellent, particularly in the North Atlantic. A lot of battleships survived through the interwar period not necessarily because they were excellent, but because arms-control treaties precluded new construction that would have outmoded them.

That having been said, clearly the Royal Navy was a lot happier with Queen Elizabeth–class battleships than with the slower R class. Remember, too, how few World War II capital ships were tested in the mission for which they had been conceived—and how often disaster was due not to some basic design flaw but to a detail. Off Guadalcanal, the South Dakota (BB-57) was temporarily knocked out not by enemy fire but by a circuit breaker that was probably tripped by the vibration of her own propeller. While the tripped breaker was a detail, the vibration was a design flaw, but surely the ship’s basic design was not to blame.

To make matters more complicated, it is difficult to compare ships within a navy, let alone on a navy-to-navy basis, because different navies usually operate under rather different conditions. The British, who had long operated in the rough North Atlantic, were better at designing seakeeping hulls than the U.S. Navy during the Cold War. And the need for improved seakeeping resulted in the Arleigh Burkes’ unusual hull form.

Comparison within the U.S. Navy is difficult because so few officers individually experienced ships of different designs (but with much the same mission) at much the same stage of their careers. The comparable stage of career is important; an ensign and a captain on board the same ship at the same time will generally have radically different experiences. Further complicating matters, much obviously depends on the systems and weapons on board those ships. A ship armed with her original surface-to-air missiles performs far worse than the same vessel equipped with upgraded weapon systems.

 

 
 

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