Book Summary: "How Carriers Fought: Carrier Operations in WWII" by Lars Celander
Title: How Carriers Fought: Carrier Operations in WWII
Author: Lars Celander
The author examines the technology, strategy, tactics, logistics of aircraft carrier operations in the Pacific Theater of World War II. It is an excellent case study of the interaction between technology, skills, social organization and values in the field of combat.
It all started as an itch. Having read many books and articles on the big carrier battles of World War II, there were still a number of things I did not understand. Things like what actually went on and why things happened the way they did. I looked for books that told me not so much about the "what," "why," or "when" but about the more elusive "how."
I wanted something written more from the perspective of a commander, a tactician, a systems engineer, or an analyst, not a traditional historian. How did they do it? Why did they do it like that? Could they have done it a better way?
In short, not finding the book I wanted to read, I wrote it myself. This new type of naval warfare gave rise to a whole new set of problems involving a range of evolving technologies including navigation techniques suitable for aircraft, radio communications, landing on and taking off from a small flight deck, managing large numbers of aircraft on the flight deck and in the hangar. There were also the very considerable issues involved with formation flying and executing coordinated attacks. Torpedoes and torpedo bombing techniques were developed, as were dive bombing techniques, initially seen as a very radical form of attack. Simply finding the enemy was a major issue; it was revolutionized by the introduction of radar. All this development went on for many years without any opportunity for testing within a battle situation. Every time a new and more powerful aircraft type was introduced, the goalposts moved.
When the war started, nobody really knew what would happen. Nobody really knew anything about carrier operations. There were lots of theories and opinions, sometimes strongly expressed, but at the end of the day, nobody could know for sure how it would all work out in actual combat.
True airborne air-search radar (AEW) requires a large rotating antenna, the bigger the better. The first real attempt in this direction was the USN mounting an AN/APS-20…. It represented nothing less than a revolution in both carrier warfare and in naval warfare in general.
From a systems point of view, carrier planes were very much expendable while the carriers represented the core of a very large investment. A Hellcat cost in the order of $50,000 to produce, whereas an Essex class carrier cost about $50–75 million. A carrier is then worth about 1,000–1,500 planes.
The maneuverability of a ship and the skill of the captain were perhaps as important as any other factor in the survivability of a ship. A fast and reliable way to get sunk was by not maneuvering.
Before the war, Japan depended almost entirely on the US for oil imports. This source was cut off by Roosevelt in July 1941 in order to force Japan. Indies).
Before the war, Japan had also built up a fleet of about 100 tankers to transport both crude oil and refined products to where they were needed but wartime consumption proved larger than expected and the shortage of transport capacity became a major bottleneck. When these tankers then began to be sunk in large numbers by US submarines, the resulting shortage of fuel oil became a severe constraint on Japan's ability to wage war.
Looking at the Midway operation, the ships involved burned about 200,000 tons per month at cruising speed with no allowance for combat. This operation alone used up all the oil (and tankers) budgeted and could not really have been sustained beyond a few weeks. The IJN had a very real logistics problem, and much of how the IJN operated during the war, what it did and did not do, can be understood from these numbers.
These numbers should be compared with US production. The IJN consumed over 12 million tons during the war, which is what the US produced in about two weeks.
It was only in 1944 that the USN had developed the high-resolution and height-finding radar and the IFF and fighter direction techniques required for effective defense against a major carrier strike, not to mention large numbers of well-trained pilots in superior fighters.
On December 7 [Pearl Harbor], the advantage lay strongly with the attacker [due to lack of effective radar and fighter direction]. A carrier raid was very difficult to defend against. Out of nowhere, a powerful strike force can approach at 150mph.
The first of the new Essex class of carriers was only a few weeks away from launch, as was the first of the Independence class. About a dozen more carriers of these two classes were on the slipways, being built at a feverish tempo. Production of the 40mm Bofors was ramping up, and the new carriers would all be protected by large numbers of this the most effective AA weapon of the war. The Hellcat was just days away from rollout and first flight. The new carriers and the new fighter would all begin to join the fleet at Pearl Harbor less than a year after this battle.
The battle [of Midway] was over but in the background that huge disparity in industrial capacity was whirring away. In the preceding years, Japan had spent a good deal of its national fortune building a very impressive navy. The problem was that it was essentially a one-shot navy. Now that shot had been fired. Japan would struggle to replace its losses. It would go on to have trouble even keeping its navy fueled.
Battle of Santa Cruz Islands 1942
With the recent improvements in AA capability on the USN ships, mainly the new quad 40mm Bofors mounts but also the presence of both battleships and the new Atlanta class AA cruisers, the number of planes shot down by AA had started to become a real factor. Up to this time, AA mostly had the task of ruining attack runs and throwing off the aim but now planes were actually being shot down with some regularity. There were stories of IJN pilots who on returning to the carriers were so badly shaken that they were barely coherent.
Like Midway, this battle illustrates well how difficult it is to operate a carrier in a prolonged engagement. The problem of how to continuously update defensive CAP and to land and launch both search and deck loads of strike planes, while under constant attack, has no solution. Flight operations require steaming a steady course into the wind which is out of the question while under attack. The carrier is also the most vulnerable, with planes on its decks in various stages of refueling and rearming. How to split up functions among the various flight decks, and how to conduct strike operations in general was at this stage a largely unsolved problem.
Battle of the Philippines Sea 1944
The situation of 1942, in which both fleets had carriers that were essentially eggshells armed with hammers, had by now changed in favor of defense. The USN combination of large numbers of fighters, aided by well-trained fighter- direction teams using accurate and long-range radar and with capacious radio networks, proved very effective. With hugely improved defensive capabilities, the first strike became much less important. The first strike was simply shot down.
It was understood that in the overall strategic offensive, the fast carriers were now basically a defensive force with the main task of ensuring local aerial superiority, despite aircraft being shuttled in from neighboring islands.
This is why so much attention was paid to improving defenses and why the number of fighters had been increased by so much. The old days of scouting and raiding was over: the rise of air power had forced the fast carriers into a basically defensive but strategically much more important role.
Pre-war Japanese Strategy
The Japanese carrier force was entirely geared toward offensive warfare. In this role it was very good, the best in the world at the time of Pearl Harbor.
It is easy to criticize Japan for its various failings in how to fight a war of attrition, the slowness to change, the deficiencies in logistics and in pilot replacement, but all that is to an extent beside the point. Had resources been diverted toward a more attritional and/or defensive kind of war, there would have been less focus on the offensive and those initial successes would not have been quite so devastating for the Allies.
The Japanese entry into the war was essentially a gamble. They gambled that a democratic USA would not go to a full-scale war with all the sacrifices that that would entail. A necessary part of the gamble was to increase the apparent cost of going to war by inflicting spectacular defeats. Everything was geared to winning that gamble. Once it had failed, the war was lost.
However, in going for an all-out offensive, the Japanese played the game as well as they could have.
They hoped that the attack on Pearl Harbor would be a knockout blow. The reality is that the Japanese did not have the resources to mount anything close to a knockout blow. They did what they could and hoped it would suffice, even though it was in reality only a raid on an outpost.
Once it was clear that that basic gamble had failed, the Japanese adopted plan B: defend so successfully that the Americans got tired and lost interest. In the execution of plan B, their main hope was to win a decisive battle, avoiding the war of attrition they were certain to lose. The only problem was that to the extent that these decisive battles were fought, they lost them.
The American Giant
One can only be impressed by the speed and skill with which the American giant responded once awoken. There were many deficiencies in the 1942 battles but by 1944 things had been sorted out, everything was in place, and a huge and very efficient carrier task force had been formed. A good example is the breakneck speed with which the USN was expanded and equipped with 40mm AA, radar, and more powerful aircraft.
The Americans outspent the Japanese by a factor of about 6–10 during the war, depending on the type of expenditure. It showed. Some of the slightly frivolous expenditures were the VT fuze and the Iowa class battleships, both of which cost large sums of money with quite little to show for it. The simple truth was that the US could afford it. It spent about $300 billion on the entire war effort (out of a GDP of about $100 billion in 1940 and $215 in 1945). This is equivalent to about 5,000 Essex class carriers.
One of the most expensive projects of the war was the B-29, costing $3 billion in total with similar amounts spent on the B-17 and B-24. Each of these projects was then the equivalent of about 50 Essex class carriers. To put things in perspective,
a hundred or so fleet carriers was simply within the margin of error of the overall war effort. During the same time, Japan was hard pressed to build a handful of carriers. After 24 Essex class carriers had been built, the US could easily have kept building them by the dozens but there was simply no need for more.
The massive air power that all these new carriers brought with them could dominate not only the Japanese fleet but also Japanese land-based air power. This was not understood in 1942 but became clear during 1944. By then it was realized that the slog up the Solomons, along New Guinea, through the Philippines, and along the Chinese coast was no longer necessary.
The huge US fleet of 1945 could go basically anywhere. Not even land-based air power could stop it. As the ultimate Mahanian expression of sea power, the entire Western Pacific could have been bypassed with the fleet sailing straight from Pearl Harbor into Tokyo Bay in what would have effectively been a repeat of the Perry Expedition.
In retrospect, the Japanese decision to go to war was an utterly disastrous one taken by a group of culturally isolated individuals constrained by their own group dynamics. The only person that could take on the group, with any hope of success, was Emperor Hirohito himself. He eventually did and that ended the war.
The end of the war came as a surprise to many. The general expectation was that the Japanese would fight to the last man.
Factors Driving Evolution of Carrier Operations
An important driver was radar technology.
A major change during the war was the evolution of effective fighter direction but this was a change in methodology and not so much in technology.
Air search mounted on aircraft, the AEW technology, was a big step forward in that it extended range and by giving low-level coverage, removed much of the weaknesses of ship-based systems. It also effectively removed the risk of a carrier bumping into enemy surface forces.
One major factor seems to have been a widespread underestimation of the importance of defense.
Massive developments in technology during the war did not change things that much. The really important developments were much more in terms of a better understanding of the realities of carrier warfare.
The underlying driver of all carrier warfare is of course aircraft engine development. More powerful engines meant bigger bombs carried at longer range.
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