Flawed Masterpieces
By David Hughes
December 2018

Pity the designer of a Second World War at Sea game as he ponders what defence value to give to a modern battleship. The number of variables is immense. The most obvious is the thickness of both belt and deck armor, but this is affected by the area covered and the quality, type and inclination of steel used. Underwater protection is equally important, but here the number of factors involved explodes, ranging from the width and filling of the protection system to how far down the main armor belt extends. Add the issue of turret armor, consider the beam of a ship (which influences whether a shell which gets through the armor will reach a magazine), decide whether it matters whether or not the captain is protected, and one is getting close to determining what the protection value should be.

The new United States battleships of World War II had excellent deck protection — thick and placed on an upper deck — probably better than any European battleship, not surprising since the United States Navy designed its ships to fight the Japanese Navy at long, very long ranges in the clear air of the Pacific, using spotter aircraft to control gunfire. Note the weasel word "probably," since there are so many variables to consider. Of these the most significant is the quality of armor, not just its thickness.

Perhaps to many readers' surprise, the United States was not able to manufacture the best type of battleship armor, known as "face-hardened" (Class A in American terminology) in adequate quantities. That which it could produce was seriously inferior to, for example British and Italian armor. I am going to try to avoid a string of statistics in a Daily Content article (for those go to innumerable Internet sites) but will consider one very common comparison between Iowa and Vanguard (King George V has a virtually identical armor system, but is a smaller ship).

Put exceedingly simply, the American belt is just over 12 inches, the British just under 15 inches. However, if we take into account the relative quality of the steel, the British belt "increases" to over 17 inches. Incidentally, Italian and probably French face-hardened steel was also superior, while the Japanese is marginally inferior. Also the sad shortage of American face-hardened steel meant that only the upper half of the belt could use this type of armor.

Old and new. Wisconsin tied up alongside the wreck of Oklahoma, 1944.

It is always assumed that the inclined belt of the American battleships was a distinctive advantage, and indeed its inclination of 19 degrees equates to a thickness of 17.3 inches of vertical armor at 25,000 yards range, although this improvement was much reduced at closer battle-ranges. However, it is also forgotten when comparing modern battleships that almost all used inclined armor. The slab-sided King George V class appears to be an exception, but it had a more complex system, vertical where the ship had its greatest breadth, but inclined (at up to 14 degrees) beside the turrets. As with the Bismarck, this meant that the water-line armor would be at a greater distance from critical points placed along the centre-line of the ship.

Unlike the King George V class, the belt of all three completed American battleship classes was internal. This is a convenient way of saving weight, but means that there is an empty space between the belt and the hull, which was made of heavy (not armoured) steel. This created a problem, shown when South Dakota was fighting Kirishima. Cruiser and even destroyer shells proved quite capable of piercing the hull so that the battleship took on over 800 tons of water. She was fortunate to be saved by Washington allowing her excellent damage control parties to check most of the water-flow.

One of the reasons some modern commentators ignore this problem is their assumption that the thin outer skin "de-capped" armor-piercing shells (stripping its very hard outer coat). This was always a dubious assumption, since ship designers made no such claim and it has now been determined that the hull "armor" had no effect on British, German and Italian shells or, one suspects, on Japanese ones. The problem with internal belts was quickly recognised when ships equipped with them went into service. Just as the Royal Navy replaced the internal belt of Nelson with the external of King George V, the United States Navy was making the same change just as the first Iowa class were being built. The truly magnificent Montana class (by virtually any calculation the best battleship design ever authorised) instead used a thick external inclined belt.

The magnificent Montana class.

American designers placed great emphasis, more than any others, on protecting the main turrets and the control towers. The former got some 19 inches of armor, almost 30% more than their British, German and Italian contemporaries, although it should be noted that this was partly because of the lack of face-hardened steel. Non-hardened (homogeneous) steel needed to be thicker to achieve the same effect.

Much more controversial is the massive protection given to the control tower. While the captain’s station of King George V had to make do with a mere three inches of armor and an Italian captain had nine inches of armor, an American captain was safe behind a towering column of 17-inch-thick armor plate. Only the mighty Yamato provided its command crew with thicker protection. In all probability this was wasted effort and possibly dangerous, as this mass of steel was located so high up in the ship. After the war it was recommended (but not implemented) that the armoured columns be reduced or removed, as the stations protected could be easily duplicated in other parts of the ship.

None of this is intended to suggest that Iowa and her earlier siblings were poor designs or inferior ships. In several critical respects they were superior to those of other nations. However, because they were active long after other battleships had been scrapped they assumed almost mythical properties. While sailing beside Jean Bart or Vanguard an Iowa looked good but not outstanding; when they were gone they became “the very best, ever.”

Consider a contemporary case. Today just about every American writer or television program will state, not merely claim, that the M1 Abrams tank is the "the best in the world." Very understandable and patriotic and no doubt exactly the same as a German would claim of the Leopard II, a Frenchman of the LeClerc or a Briton about the Challenger II. Because these complex and competent tanks exist side by side we can compare and recognise that all have strengths and weaknesses, such as the superb protection but inferior engine of the Abrams.

Surely when we are judging the values we put on cardboard counters we can recognise that 60 years ago the same applied to battleships. That, for example, South Dakota had superb engines, magnificent damage control but inferior quality amour. Or that the heavy shells in her guns were better at penetrating enemy armor, but because their extra weight was achieved by reducing the explosive content, might cause much less damage if they did.

The end. South Dakota and two cruisers laid up at Philadelphia, 1961.

Remembering that all were truly magnificent, superbly protected, and seriously deadly warships, I will in a future Daily Content suggest some amended values for these ships in Second World War at Sea.

See for yourself how the U.S. battleships perform
in Second World War at Sea: Arctic Convoy!