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LT. Mason is currently serving at the Naval Postgraduate School.

Executive Summary

There were many factors that contributed to Allied victory during World War II in the Battle of the Atlantic. However, paramount among these were Gennany’s failure to innovate and adapt to changing circumstances, the successful knitting together of Allied anti-submarine warfare commands, the development of sound ASW and convoy doctrine, the development and growth of American industrial potential, and the changing role of cutting edge technology on the battle field. While each of these factors certainly played a part in the ultimate Allied victory, it is the sum total of these parts that truly made a difference and paved the way to resolution of this conflict in history.

In true Mahanian fashion, the Battle of the Atlantic was Germany’s attempt to cut the sea lines of communication between Britain and her allies- most specifically the United States, and thus strangle their primary protagonist within the European theatre. The fact that this did not occur can be traced back to several strategic, operational and organizational factors whose combined influence enabled those pages of history to be written as they were.

The Allies won the Battle of the Atlantic because they 1) capitalized on Gennany’s failure to innovate and adapt to changing circumstances, 2) recognized the strategic value of organizing and “intertwining” the various intelligence communities with those facets of high command charged with the direction of shipping and ASW in the Atlantic, 3) understood the importance of exploiting the vast industrial capacity of America, 4) valued the imperative necessity for both inter-agency and intranational cooperation in applying sound ASW and convoy doctrine, and finally, 5) recognized the operational level influence of innovative ASW tactics and the role of advanced technology.

Pride of an Empire

“Impossible to see, the future is … ”

In the early months of 1942, the Gennan U-boat command embarked upon an unprecedented massacre of military and merchant vessel traffic that stretched from as far North as Newfoundland and as far South as the Trinidad Islands. Eagerly enforcing Grand Admiral Karl Donitz’s ideal of guerre de course, U-boat commanders succeeded in sinking an average of 650,000 tons of war material per month. (Cohen and Gooch, p. 59) This unprecedented assault on the life-blood of the Allied war machine foreshadowed grim prospects of a positive outcome to the war for the Allies.

When considering the central objectives of undersea warfare, it is important to note that, at least in the early part of the war, Donitz superbly exploited the strategic and tactical value of undersea concealment. This fact was clearly illustrated on October 141 th, 1939, when Gennan U-boat commander Gunter Prien successfully infiltrated the British fleet anchorage at Scapa Flow. Aided by the complete absence of any form of ASW response, Prien’s torpedo attacks quite efficiently sank the British Fleet’s flagship, Royal Oak at her moorings. In the confusion that followed, U-47 made good her escape where upon their return to Gennany, Oberleutenant Prien was promptly hailed a hero at having penetrated the previously impregnable British Naval stronghold. (McKee, p. various) Another key to Germany’s initial maritime success had to do with an enormous error on the part of Allied commanders, who failed to match the correct organizational structure to the problem of ASW and convoy transport. (Cohen and Gooch, p. 79) It is ironic that at the time, the Royal Navy’s Operational Intelligence Centre’s ability to collect intelligence via various sources, and then organize and collate that data efficiently was supremely successful. However, Allied forces continued to sustain losses because this vital information was not being disseminated to waiting unit commanders quickly enough.

Yet, these major advantages that German Naval commanders enjoyed were quickly squandered when they failed to
realize that their initial successes were based on circumstances that could change, thereby necessitating organizational and doctrinal adaptability and flexibility in order to successfully mitigate these newfound risks. However, unmindful of this error, previously sound undersea warfare doctrine grew lax and outdated, and with the advent of Allied convoy shipping techniques and a significant increase in available British and Allied anti-submarine patrol aircraft, Germany’s undersea Navy became largely ineffective. Ultimately, under pressure from the Fuhrer, Gennany’s Navy became more surface-centric, and by late 1943, Admiral DOnitz’s wolf-packs were operating increasingly as solo combatants and in oceans of necessarily low strategic value.

Intelligent intelligence
“Viva la Revolution”
-Che Guevara

The next reason that the Allies ultimately won the Battle of the Atlantic was because they recognized the strategic value of organizing and “intertwining” the various intelligence communities with those facets of high command charged with the direction of shipping and ASW in the Atlantic. This impressive revolution in military affairs began to bear fruit in the spring of 1943, when Allied losses due to U-boat attacks had declined considerably (See Figure 2). Paired with the influx of new shipping assets such as the Liberty and Victory class ships, merchant shipping gains exceeded 1.2 million tons. What is more, the predator had now become the prey, where Allied “hunter-killer” groups accounted for 16 U-boats sunk in the summer months of that same year. (Baer, p. 204) This impressive tum-about was a direct result of the Royal Navy’s Operational Intelligence Centre, whose ability to collect intelligence via various sources, organize and collate the data efficiently and then disseminate that vital information to waiting unit commanders was so successful that by the end of the war, they had received permission to communicate not only “hard” intelligence, but also well educated guesses made by talented analysts on the movements of German U-boats.

(Cohen and Gooch, p. 76) This revolutionized the Allies’ capacity to safely conduct convoy traffic across the Atlantic Ocean by routing them away from waiting wolf-packs, as well as direct scarce surface and air assets to both escort those convoys potentially in danger, as well as destroy tracked U-boats. Hence, the German submarine threat was overcome, not as much by killing the predator (though that did occur and in increasing numbers in late 1943), but rather by making the “prey” less vulnerable. (Baer, p. 199) While the achievements of the Royal Navy’s OIC, and subsequently later in the war, the US’s TENTH FLEET were indeed impressive, what made this organizational factor remarkable was the astonishingly efficient command and control (C2) structure that encouraged this free exchange of information. It has already been mentioned that DIC had a direct line to the Allied unit commanders, but in addition to this closely knit link, one must note as well that OIC communicated directly with the RAF and the Royal Navy, making swift use of all of the intelligence at their disposal to improve and standardize existing ASW doctrine. Their range of influence expanded further when the US established their own organizational analog to Britain’s in the form of the TENTH FLEET, under ADM King. Ironically this command did not own any ships per se, but did put into practice the hard lessons learned by the Brits. (Baer, p. 203) Indeed, under British guidance allied ASW operational strategy slowly but surely evolved from a prewar ambivalence to reactionary defensive tactics, and ultimately to offensive ASW operations bound under centralized control. (Manke, p. 2) Interestingly enough, this organizational concept had not yet been fully developed at the beginning of the war and the Allies
were losing tremendous amounts of war material as a result.

Gennany had, at the time, a secure means of communicating with all of her submarines and when taking into account the limited number of vessels ADM Donitz had at his disposal, Gennany’s guerre de course was tremendously effective. However, this advantage was gradually eroded due to Oonitz’s proclivity towards centralized control (resulting in excessive radio transmissions) and his somewhat paranoid grip on an under-manned and overworked staff. While Allied forces were expanding their intelligence and control operations, Donitz was slowly weeding out the “leaks” from his command.

Fueling the War Machine

“An anny moves on its stomach … ”
-Napoleon This next point that was instrumental in the Allied victory in the Battle of the Atlantic is rooted in the grand strategic development and leveraging of America’s vast industrial potential.

President Roosevelt, having seen the proverbial “writing on the wall,” began an aggressive in 1941 to build u the Allied transport capability. In so doing he transformed the concept of women in the work place; a notion that quickly caught fire, and was spurred on by popular images such as “Wendy the Welder”, and “Rosie the Riveter.” Roosevelt’s idea worked brilliantly, stirring the emotions of Americans nationwide and resulting in an outpouring of support.

The first of the Liberty cargo ships were launched that September and by war’s end American shipyards had produced over 2,700 sister ships of similar design. The manufacturing process became so efficient that even during the darkest months of 1942 where Gennan U-boats claimed 1.3 million tons and thousands of lives; still the US was able to replace the merchant vessels sunk by enemy actions. (Murray and Millet, p. 258) The key to this prodigious rate of production was found in the plan of modular design and the manner in which they were assembled. Cargo vessels were prefabricated in sections which then enabled the final assembly to proceed with unprecedented speed. Additionally, the US had a sizable and willing workforce of spouses and under and overage men. In essence, the whole of America pitched in to aid the war effort. These facts coupled with ADM Donitz’s weak initial salvo in the commerce war, enabled the US to jump-start its ship-building industry early and ultimately meet the needs of the Allied shipping pool. (Murray and Millet, p. 259)

(Not-so) Jointness

“Individually, we are one drop. Together we are an ocean.”
-Ryunosuke Satoro

Initially both Great Britain and the United States suffered from a division of and intolerance for their respective air and surface units. Unfortunately, this was a mindset shared by ADM King, CNO and Commander in Chief of the United States Fleet, and resulted in millions of tons of war material lost.. .not to mention much friction between the Americans and their British counterparts. The true root of the issue lay in the jealous distribution of duties and zealous protection of each individual’s sphere of influence. For the Americans, control of convoys and the various escort vessels was severely disjointed. For example, the long range maritime patrol aircraft needed to provide air escort for convoys were owned by the Army Air Force, but the mission and hence responsibility for providing said support was wholly the Navy’s. This inter-service squabbling was also reflected in the Royal Navy and Air Force. In fact, it was not until the last months
of 1942 that the RAF Coastal Command even began to provide air
escort for the beleaguered convoys. (Murray and Millet, p. 236)
This sort of tension could also be found between ADM King
and the British as a whole. Arguably an Anglophobic and hard
man, King disagreed with the notion of a convoy due largely in
part to a past failed attempt (specifically, the American-Canadian
North Atlantic convoy in 1941 ), but also perhaps because the
British so forcefully heralded its effectiveness. Hence, his dictum,
“inadequately escorted convoys are worse than none” prevailed
until the incredible losses sustained in 1942 convinced him
otherwise. (Baer, p. 196)

What makes this a factor in Alliance victory? Consider the following: King’s stubborn refusal to implement established and effective convoy doctrine during the early years of WWII encouraged ADM Donitz to continue U-boat operations with little to no tactical or doctrinal evolution. Hence, once ADM King recognized his error, the sudden and swift move to standardize this form of transport throughout the US merchant and naval fleet virtually paralyzed Germany’s U-boat fleet. One also must not overlook the value of “shared” air cover over the North Atlantic, as evidenced in mid 1943 when US B-24 Liberator’s and Britain’s S.25 Sunderland closed the air escort gap and contributed to the sinking of 135 U-boats in three months alone. (Murray and Millett, p. 256)
A Technological Revolution
“Necessity is the mother of invention … ”

From an operational viewpoint very little had changed in the way of anti-submarine warfare at the beginning of WWII. Though the British had learned a few lessons from WWI regarding this battle beneath the seas, at that time the technology had not truly progressed to the point of effective applications for countering this new threat. ADM Donitz was a remarkable U-boat commander and pioneer in devising new tactics for their use, but he largely ignored the importance of technology. (Baer, p. 191)

What helped salvage this theatre of war for the Allies was the sudden, nearly frantic scramble for technological innovation which gave the Allies the advantage it sorely needed. Pioneering scientists and military personnel, primarily from Great Britain, answered this call spectacularly in the form of airborne RADAR, improved SONAR, torpedo countermeasures, radio direction finding (D/F) equipment and the advent of signals intelligence.

Though initially met with little success, the ability of Allied commanders to locate and track German U-boats via their radio communications quickly proved vital to the war effort. This was because in February of 1942, the Enigma code- which had originally been deciphered at Bletchley Park, was rendered temporarily unusable with the addition of a fourth wheel. Hence, SIGINT became the primary means of tracking German U-boat operations. (Murray and Millet, p. 252) Perhaps less eloquent, but equally important were the advancements made to SONAR, which enabled Allied forces to locate submerged submarines, the British 271 M radar, to pinpoint surfaced U-boats, and finally, improved yield depth charges, to ultimately put the attacking Uboat on the bottom.

While the ebb and flow of political pressure did have an effect on the US ultimately adopting Great Britain’s convoy and ASW tactics, one simply cannot deny the role changing technology played in shaping those very same tactics, techniques, and procedures. While the Americans and Brits adapted strategy and utilized cutting edge technology to counter the U-boat threat, Donitz simply moved his wolf-packs to easier
hunting grounds (specifically the Caribbean). This coupled with his lackadaisical approach to technological innovation put Gennany at a severe disadvantage and would ultimately pay the price with her national blood and treasure. (Murray and Millett, p.256)


There are many other factors that contributed to Allied victory in the Battle of the Atlantic; however it was the strategic insight afforded by the unique organization of Allied intelligence and control departments and the goading of the ponderous American industrial engine that ultimately won the day. The necessity of inter-agency and intra-national allies working together and standing united in the face of an implacable foe was illustrated first by their initial failure to do so (and subsequent tragedy of 1942,) as well as the follow-on success-story years of 1943 and 1944. Gennany’s high court blunders certainly facilitated this particular issue as well. Finally, while a nation must never place all of their eggs in the technology basket, one cannot discount the importance of innovation and advancement in the art of warfare.

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