Did Strategic Bombing lengthen the war?

John T Kuehn's picture

January 2019 Hand Grenade

Did Strategic Bombing lengthen the war?

John T. Kuehn


A book I am currently reading makes an interesting argument.

Here it is.

Because of Winston Churchill’s infatuation with the promise of strategic bombing, and the willing complicity of the leadership of the RAF (with exception of Hugh Dowding),  the great war in the North Atlantic between U-boats and convoys took much longer to reach the point of success for the Allies (summer of 1943).  The author went on to claim that this likely lengthened the war, giving the Allies fewer options because of the ongoing dire U-Boat threat through 1943.

Why?   Argument goes that the U-boats were at a severe disadvantage against long range air that could have been provided by RAF Bomber Command (or by bombers flying for US Army Air Force, whose leaders also though bombers alone could win the war).  Too, airborne surface search radars already existed that could have been installed on long range bombers much earlier in the war.  They were already in use, for example, at the battle of Midway in June 1942on PBY Catalinas.

What say the faithful readers of this handgrenade?  Could the turning point of the U-boat war have come earlier had not Britain’s (and America’s) leaders not been so star struck by the promise of strategic bombing?  Secondly, what about the thesis that this might have shortened the war?

Happy New Year,  

John T. Kuehn

The technological conflict in the Battle of the Atlantic was not amenable to simple panacea solutions.

It took a system of systems to put down the German U-boats.

The earlier arrival of long range airpower with meter band as opposed to centimeter band radar during the 1941-42 ULTRA black out and without the Mark 24 Mine AKA acoustical torpedo would have spawned different/earlier countermeasures from the Germans without decisive effect.

The early arrival of a Mark XXI class capability German submarine design would have been a really awful strategic development.

Plus, the additional pressure earlier from diverted from strategic bombing to long range maritime patrol could not have amounted to much in 1942 due to the twin 1942 calls on long range maritime planes/4-engine bombers called the Guadalcanal campaign and the build up to the Operation Torch landings.

It was COMINCH King's Captain Ahab-like push of American naval patrol planes and destroyers to the Pacific that caused the 2nd "Happy Time" of "Operation Drumbeat" on the US East Coast and the Caribbean Sea,

Nothing short of FDR firing King would have changed this.

And note as well that RAF Bomber Command 's Air Chief Marshal Sir Arthur Harris started and maintained a systematic sea mining campaign against the German U-Boats through out his tenure at Bomber Command.


Bombers, ‘Butchers,’ and Britain’s Bête Noire: Reappraising RAF Bomber Command’s Role in World War II
by Dr Robert Ehlers

"Bomber Command aerial mining missions in the Baltic also led to major German shipping
losses (and the vital high-grade Swedish iron ore they carried) and delayed sea trials of new
U-boats such as the Mark XXI. These new boats could not have turned the tide, but they would
have caused much greater shipping losses. Instead of getting 20 or more Type XXIs operational
by 1945, the Germans managed only one. Ultra confirmed these delays. Harris pushed hard for
these mine-laying missions while Deputy Director of Plans at the Air Staff in 1939. His efforts
paid off. By April, 1940, Hampden bombers were deploying magnetic mines—an operation
that grew dramatically in scale, sophistication, and effectiveness when Harris took charge at
Bomber Command. By VE Day, Bomber Command had deployed 47,000 aerial mines and
engaged in other raids that sank 717 merchant vessels and damaged another 665. This effort
extended to the Danube River, where Bomber Command 205 Group’s efforts virtually shut
down Rumanian oil and agricultural deliveries to the Reich in summer 1944. Together with
the USAAF, Bomber Command also destroyed 111 U-boats in production and another 54
already delivered to the Kriegsmarine. Additionally, 423 merchant vessels were sunk between
1 January 1940 and 30 June 1943, placing the German steel position, already precarious, in a
severe predicament. Mining and ship attacks were elements in an aggregation of factors that
brought about the “steel famine” of 1943, which put a stop to Speer’s armaments expansion
until early 1944. 24

24 See Christina Goulter, A Forgotten Offensive: Royal Air Force Coastal Command’s Anti-Shipping
Campaign, 1940-1945, (London: Frank Cass, 1995); BBSU, xxxviii; RAFH, Air Intelligence, 63-64;
Probert, 99; Denis Richards, RAF Bomber Command in the Second World War (London: Penguin
Books, 1994), 180-183, 298-299."

The removal of RAF Bomber Command aircraft to RAF Coastal Command missions could well have resulted in -MORE- and better trained German U-boats in 1942-1943, as there would have been fewer long range planes to mine the Baltic waters between 1 January 1940 and 30 June 1943, and thus more steel to expand the German armaments industry.

The reason here is Prime Minister Churchill would not have forgone striking Germany for political reasons and the discretionary loss in long range RAF Bomber Command airframes would have seen the 1 January 1940 and 30 June 1943 era sea mining missions curtailed.

I would say that it is high time to put that book aside as hopelessly naïve and ill-informed.

Let me first stipulate that it has been apparent for many decades that "strategic bombing" in WW II was a bad bargain, that more could have been accomplished at very considerably lower cost (to say nothing of vastly lower collateral damage) if the airpower zealots had been willing to pay attention to the findings of the scientists who were studying bomber operations and their results (or lack thereof). But strategic bombing was (is) as much a matter of revealed truth as of reason and evidence. And this had been true long, long before Churchill appeared on the scene.

Nor is there any doubt that diverting most or even all of the production of B-24 Liberators to maritime patrol duties would have been a net gain. The plane was well suited to MPA missions (particularly in its later PB4Y-2 Privateer version) but never was a very suitable heavy bomber.

But having more long-range MPA earlier would have done relatively little to advance the turning of the tide against the U-boats, which was (like most campaign results) overdetermined. Having them fly about in the general vicinity of the convoys (if they could find them) would have been of very marginal value without the other elements.

The radar that was available (in small numbers) in 1942 was the UK ASV Mk. II and various US versions. It operated at VHF, involved high-drag external antennas that cut into aircraft speed and range appreciably, and was very inefficient against surfaced submarine targets. It provided sweep widths of the order of 10 nmi or so, resulting in practical patrol sweep rates of the order of 1,500 nmi^2/h, which was not going to get you very far in the N. Atlantic. Moreover, the U-boats were fitted with a warning receiver and so could dive and stay down until the searcher had passed. Even if a detection were made successful conversion to attack was rare at night due to the operational limitations of the equipment. For useful results microwave sets were essential and they were not available until the spring of 1943.

But even at best, radar search in the vicinity of convoys had fairly low payoff. To get real value out of long-range MPA it was essential to have escorts fitted with HF/DF so they could vector the MPA to run down the signals from trailing U-boats that were providing homing transmissions to aid in forming an attack group. Even if the trailer could not be surprised and sunk (as a good many were), driving it under disrupted pack formation. But shipboard HF/DF too was not available and operational until the spring of 1943.

Beyond all that, even if it had been possible to blunt the U-boar attack a few months earlier, how would it have materially affected the final victory? Both the timing of the Normandy landings and the rate of the Russian advance were strongly overdetermined, and they were the proximal factors in ending the war.

What is the book?

This somewhat misstates these issues. It was the insistence of Arthur Harris of Bomber Command--not Churchill--that led to the RAF refusing to allocate more than a handful of long-range aircraft to Coastal Command. Harris believed that strategic bombing, especially the bombing of German cities, could and would win the war. He refused to let Coastal Command have the long-range B-24 Liberators which eventually did close the famous "Mid-Atlantic Air Gap." The major effect of these planes was not successful bomb attacks on U-boats, but their mere presence overhead. Submarines will not operate if hostile planes are in sight. The radar issue is more complicated, and Bernard Lovell's Echoes of War has a detailed technical discussion of these issues, specifically using radar--first long-wave, then centimetric--for both area bombing and attacks on U-boats. The defeat of the U-boats in May 1943 came from a combination of factors, nicely laid out in the Wikipedia article on Black May 1943.

The greatest U-boat threat was during the first years of the war, and also the period of the least effective strategic bombing campaigns in Europe. Had more long range aircraft been given to Coastal Command (in the RAF) and/or used either by USAAF or USN crews in ASW patrols, there is little doubt that U-boat effectiveness would have been significantly reduced. Except during actual attacks on convoys, which were only a small percentage of the U-boats time on patrol, the biggest threat to, and the greatest fear of, the U-boats was aircraft attack. Even without ASV radar an attacking aircraft had a good shot at catching the U-boat on the surface, and even an attack which did not damage the boat but forced it to remain submerged for some time was a success. A submerged U-boat was not going anywhere in a hurry, and its position was now marked for further attack and/or avoidance by convoys. Remaining submerged and using the snorkel, which was not available until later in the war, would do a better job of hiding, however speed of advance was still limited. Additionally the conditions in the North Atlantic make using the snorkel uncomfortable at best and impossible much of the time - even moderate sea states render snorkel use almost impossible to tolerate.

Closing the air gap sooner and putting more ASW aircraft in the sky would most probably have tilted the Battle of the Atlantic in favor of the Allies sooner, though I would not venture to say how much sooner. Would it have ended the war sooner, at least in Europe, I am less sure about that. Even had the flow of supplies and troops to England and beyond been increased over as it was, I doubt you would have seen a successful D-Day substantially sooner. Conditions in April are not good enough in the Channel, so perhaps May.

In any case the actual number of aircraft needed to do this was relatively small compared to the numbers devoted to strategic bombing (and the losses involved). Unfortunately there was and still is a tendency to look for the magic new technology that makes victory "cheap and easy", which in WWII was "airpower". Not to say air dominance is not a very good thing to have, it is, but it is still only one leg on the stool. There are lots of ways to destroy things but if you want to control it (at least on land) you need to have "Marine Corps Cadillacs" (ie: combat boots) there. At sea, if you are not right there right now with ships or aircraft, no control. Due to the lack of LRA the U-boats were there and the Allies were not.

Landing in Italy at the bottom of "the boot" was a strategic dead end. It gave us new bomber bases but would not allow for the invasion of Germany. Not until 1944 did the Allies achieve all the prerequisites that allowed them to land in France ( adequate landing craft inventory, air superiority and US battlefield experience against the German Army). Air superiority might have been gained by the end of 1943 had the US Air force recognized earlier the potential of the Mustang/ Merlin engine combination, so maybe D Day could have happened in April/May as opposed to June ( channel weather would not allow winter landings). None of this had to do with shipping losses due to U boats. After D Day, why the war did not end earlier has a lot do do with mediocre generalship by the Allied armies ( diversion of excessive forces to capture Brittany, the Falaise pocket fiasco, the needless Hürtgen forest hemorrhage of infantryman , Market Garden, failure to pinch "the bulge at the base rather than squeezing from the center, failure to capture the estuary of the Scheldt to allow proper access to Antwerp in September, among others) . To these I could add (once air superiority was obtained)) the fixation on the wrong targets by the air forces until late 1944.
Nevertheless , there is no denial that prioritizing the production of a few squadrons of very long range B-24 ( the only ones capable of closing the mid Atlantic gap) and assigning them to U boat interdiction would have saved a lot of lives and treasure.

The assertion that the RAF's and USAAF focus on strat bombing either lengthened the battle of the Atlantic and/or lengthened the war quickly get into the usual blizzard of counter-factual ripple effects. And I must admit that I haven't seen the book/article making the cases for either result. But I think it's a pretty weak argument. Consider:

- in 1941/1942, there weren't all that many long-range (4-engine) strategic bombers available. Consider that the "Millenial" (1000-bomber) raid on Cologne (30/31 May 1942) was by far predominantly twin-engine types (Wellington, Manchester, Hampden, even a few Whitleys).

- The mid-Atlantic gap was not covered by 4-engine Land-based Air until the Azores were opened up for Allied use in late 1943. So detailed to the mission or not, the land-based air available in 1941/42 could not help cover the mid-Atlantic.

- A major portion of the Allied bomber force WAS aimed at the U-boats. It was costly and utterly ineffective before the RAF developed Really Big Bombs (Tallboy, Grand Slam etc) to penetrate the sub-pens--i.e., before 1944. But reluctantly or not, the "Bomber Barons" did in fact honor the Combined Chiefs of Staff agreement that defeating the U-Boat was priority. Knowing what we know now about the effectiveness of those attacks, a "best of both worlds' agreement to take maybe 1/4 of the 4-engine force and delegate it to Coastal Command etc while not asking the rest of the force to bother with the sub-pens at all would have been a lot more effective for both missions.

A lot of factors came together in early 1943 to effectively win the Battle of the Atlantic. Those included things like more code breaking success, countering German code breaking, more escorts, CVEs, hedgehog ASW weapons, better HFDF equipment, etc. Even the Leigh Light searchlight was only introduced in mid-1942 (allowing visual acquisition at night before the attacking aircraft moved into the radar "too close blind spot" and lost the target). There was also the tech race of Allied radar vs the Metox and Naxos radar detectors. So while more 4-engine Coastal Command air would certainly have helped, it's tough to see that it would have made more than an incremental improvement in tipping the balance.

As for shortening the war: that argument probably assumes a major improvement in the Allied shipping crisis (admittedly THE major strategic LIMFAC on Allied operations). But exactly how would that shipping have been used? For example, additional shipping could have saved thousands of lives from famine in India--very important (obviously), but a non-factor with respect to shortening the war. Given the number of oddball strategic ideas squashed by shipping shortages (ex--British ambitions to dither around in the Eastern Med), one could even argue somewhat tongue in cheek that the shipping shortages forced focus on the true priorities without allowing (in Marshall's phrase) a "dispersion debauch" that inadvertently would have lengthened the war/left it ending with the USSR farther east, etc.

Put another way, any argument that says (1) putting more 4-engined aircraft into ASW would have been generated a massive decrease in sinkings in late 1942 (the peak period of shipping losses) and (2) that shipping benefit would have been used to make the rest of the war go faster is based on two very debatable propositions.

Finally, "those goddamn bomber zealots lengthened the war due to _______" arguments tend to ignore what the Combined Bomber Offensive (CBO) *did* achieve. For example, air superiority in multiple theaters. The Luftwaffe's fighter force was dragged home in 1943 (largely clearing the Mediterranean of Axis fighters while helping the Soviets achieve first air parity and then air superiority in 1943) and then broken in early 1944 (clearing the way for D-Day). The fact that Luftwaffe attrition was driven primarily by escort fighters is irrelevant to the point that the Luftwaffe was badly hurt in 1943/early 1944 while responding to the CBO. Does the Red Army win Kursk if the Germans still largely own the skies? Even if the answer is "yes", does the Red Army advance anywhere near as far or fast if the Luftwaffe isn't deploying major fighter and artillery (German "88s", for example) forces to defend the Reich? Can the Luftwaffe deploy more aircraft to Norway to contest Murmansk convoys longer? Does that mean the war gets longer rather than shorter?

And the final phase of the war was arguably shortened by the massive impact of the CBO when the Americans (and the RAF, whenever Marshal Harris' disgust for "panacea targets" could be overcome) made a committed, sustained effort to throttle German oil production and then their transportation system (see Mierzejewski's "Collapse of the German War Economy"). Lack of fuel had tremendous ripple effects on German operations (land and air) for the last year of the European war. Give the Germans full fuel production to train and fight and a still-functioning war economy in late 1944/early 1945 would not have shortened the war.

I realize that "bomber barons" are a fun straw man to whack on, and there were those with wildly unrealistic hopes that bombing could lead to an Axis collapse. Fair enough. But one could just as easily point to land generals who felt that any aircraft not flying directly over THEIR troops was wasted effort as being mono-maniacal zealots.

Finally, any counter-factual assertions need to look for and explore secondary effects. If the argument is that bomber barons could have allocated a few more aircraft to Coastal Command that would have had more positive impact on the war than the same number of aircraft used in strategic bombing in 1942/43, I'm okay with that. As noted above, it would have had even more positive effect if the trade-off for those additional 4-engined Coastal Command aircraft would have been "and in return the rest of your force doesn't have to waste time, aircraft and aircrews on utterly useless sub-pen bombings." But to try to leap from that to some major shortening of either the Battle of the Atlantic or the war itself has to hand-wave a lot of other factors involved. And if the argument is that the CBO itself was a complete waste of time, well, no, not buying it at all. Richard Overy has done considerable good work on this subject.

I will leave discussion of the joys of fighting wars amidst fog and friction where one doesn't have complete information on the effectiveness of one's own forces (much less how things look "on the other side of the hill") for a different Hand Grenade. Let's have some humility when judging our predecessors, knowing that our posterity may apply the same "what were they thinking?" 20/20 hindsight to us some day! :)

Mike Condray
Colonel, USAF (retired)

I'm glad to see such an enthusiastic response to the Hand Grenade, surely one of the best ever. Many thoughtful points were made, and I'd certainly like to follow the crowd and weigh in.

Retired Air Force officer that I am (O-5), I endorse much of what Mike Condray said -- the combined bomber offensive was working its way toward a decisive point, albeit slowly and with horrendous losses. But there can be no doubt that the daylight offensive carried out by the USAAF ate the heart out of the Luftwaffe's fighter force during the winter and spring of 1944, so that SHAEF's invasion of the European continent could proceed with virtually no hindrance from enemy airpower. Deployment of the Merlin-powered P-51 and the crippling effects of the oil campaign played no small part in this dramatic success. As one historian (whose name I've forgotten) pointed out, after the summer of 1944 the Luftwaffe consisted of a handful of surviving expert pilots surrounded by masses of struggling amateurs, with POL shortages eliminating what had been a successful aircrew training regime.

I have long agreed with those who argue that the "Bomber barons" should have surrendered control of a number of long-range bombers, the B-24 probably the most important and useful of these, to provide more aerial coverage of the North Atlantic convoy routes. Would this have been as decisive as many people think? Yes, probably, in terms of reduced shipping losses. But I am not so sure it would have shortened the war. Despite the terrible losses to U-Boats during 1942 and early 1943, the Allies were successfully moving a lot of men and materiel across the Atlantic. As David Edgerton noted in his book _Britain's War Machine_ (2011), cargo shipping loss rates fell steadily during the war, declining from one ship sunk for every 181 at sea in 1941, to one out of more than 300 during the dark days of early 1943. (Don't you love the creative use of statistical analysis?) But I doubt that a reduction in shipping losses, even a fairly dramatic one thanks to better air coverage, would have induced SHAEF to undertake an invasion of the continent any sooner than it did.

I'm coming to think that the most likely, and possibly the only way an early ending to the war might have happened lies with the ground operations in northwest Europe -- the breakout from Normandy and the pursuit across France and the low countries, which was not undertaken in the most imaginative and decisive manner. As it happens I'm reviewing C. J. Dick's new book, _From Victory to Stalemate_, a detailed and unsparingly critical analysis of the campaign from July to late November of 1944. Dick, like many of his colleagues at the UK's justly famed former Soviet Studies Research Centre back in the final decades of the Cold War, sees the "operational art" as the most decisive level of modern mechanized combat, the only level where meaningful, large-scale results would occur. Unfortunately, of the senior Allied generals (Army and Army Group commanders, plus Eisenhower), only one -- yes, George S. Patton -- demonstrated any flair for deep operational maneuver, and he was rarely given the resources and the latitude to exercise his skill. Dick believes that the near-total destruction of the Wehrmacht Army Group in the West was within the realm of possibility during the late summer and early fall of 1944, had the Allied leadership seen the higher truth of the operational art. This would have eliminated any possibility of a German "rally" along the frontier, as occurred later in the fall. In his view, this would have further enabled the Allied 21st and 12th Army Groups to move into central Germany against negligible opposition well before the end of 1944. Unfortunately, the failure to close the Falaise Gap and the subsequent too-careful series of unimaginative thrusts along Gen. Marshall's "broad front" allowed the Germans to make the most of their astonishing resilience. Division after division was eviscerated, many thousands of soldiers killed or captured, but too many of the prisoners taken proved to be from support echelons or untrained levies such as the Luftwaffe ground forces, while a hard core of Army Group West's combat strength managed to elude capture and regroup into ad hoc kampfgruppen, with just enough men and just enough effective weaponry to put up strong defenses that forced the Allies to halt and ponderously bring forward troops and artillery in sufficient numbers to overwhelm the obstacle and continue the broad front advance.

Admittedly, the Allies had serious logistical problems, with an inability to keep every unit fully supplied across the broad front. Yes, the Wehrmacht had a few superior battlefield weapon types and the skill to employ them to their best effect. And yes, despite the Allies overwhelming air superiority only one major component, Quesada's IX Tactical Air Force, seems to have employed this superiority to its best effect, crippling the enemy's ability to conduct large-scale counterattacks or any sort of mechanized operational maneuver. And yes, the Allies had Ultra, a superb intelligence resource. But, as Dick points out, Ultra offered little or no insight into the Germans' ability to swiftly reorganize or cannibalize broken divisions, improvise command and staff cadres, and absorb the limited flow of personnel and equipment replacements so as to create these sparse but effective kampfgruppen that brought larger Allied formations to a series of frustrating, temporary halts.

So, more Pattons to conduct deep operations, accepting some risk on the flanks that would, in any case, be mitigated by intelligent employment of tactical airpower -- only this might have permitted complete encirclement and destruction of the Wehrmacht in western France. With a subsequent march by the Allied ground armies, virtually unopposed, into the heart of the Third Reich. Home by Christmas!

Jonathan Beard,

I'm going to suggest that your comment here:

" Harris believed that strategic bombing, especially the bombing of German cities, could and would win the war. He refused to let Coastal Command have the long-range B-24 Liberators which eventually did close the famous "Mid-Atlantic Air Gap.""

You are doing a grave disservice to both Sir Arthur Harris' reputation and the historical record.

The Liberators in question were not considered survivable by the RAF Bomber Command in the night bomber role over Central Germany. They were used in theaters lacking the integrated air defenses of night time Germany.

What you and apparently the author of this book John T. Kuehn mentioned in his "Hand Grenade" fail to consider are the opportunity costs of using then Coastal Command in lieu of where they were actually deployed in later 1942.

That is, how badly would the defense of Egypt been hurt by the lack if RAF Liberators?

The answer seems to be far more would have been lost by not attacking Rommel's North African Supply lines than would have been gained by flying those airframes as maritime patrol aircraft in the June - December 1942 time frame..

For which, see:

Consolidated B-24 Liberator in RAF service

and specifically these passages --

"To return to the Liberator II. Some of the armed Mk. IIs went to Coastal Command but others became the first R.A.F. Liberators to be used in the heavy bomber role. These aircraft were flown by Nos. 159 and 160 Squadrons, which formed in January 1942 at Molesworth (Hunts.) and Thurleigh (Beds.), and were detained in the Middle East in June in 1942, whilst en route to India. They appear to have arrived in the Middle East about the same time as an important British convoy was taking supplies from Alexandria to beleaguered Malta, and their first task was to help provide it with air cover. No. 159 Squadron (Middle East Detachment), as it was known, operated under the control of No. 160 Squadron, and the Liberators were at first based in the Suez Canal Zone, together with the first US.A.A.F. unit to operate in the Middle East-a formation of Liberators known as the Halverston Detachment.

Soon, however, Rommel’s advance eastwards to Alamein forced all the Liberators (which incidentally were now supplemented by a squadron of Halifaxes from Britain) to withdraw to Palestine, their place in the Canal Zone being taken by the medium Wellington bombers formerly based in the desert. The Wellingtons, even though they used advanced bases for refuelling, could not only reach as far as Tobruk, but the Liberators-and also the Halifaxes-were able to range as far as Benghazi. The C.-in-C. of No. 205 Group, which operated the bombers, issued an order: ‘Tobruk and Benghazi harbours are the front and back doors through which the enemy is getting his supplies. The front door is slowly being closed to him. There must be no back door.’ During July the front door of Tobruk was attacked in force thirty-three times, mostly at night but sometimes by day; the back door at Benghazi was attacked by heavy-bomber formations seven times during daylight. During August the Allied bombers continued to hammer Tobruk, making more than thirty-one big raids. On three occasions the Liberators made dusk attacks, appearing over the town while there was still sufficient light to see the shipping in the harbour. Each time they scored direct hits on large ships."

and later

"All these raids had the cumulative effect of practically closing the enemy’s front door of Tobruk and compelled him to divert most of his supply columns to Benghazi, whence they had to travel hundreds of miles over the desert by truck to Alamein. Benghazi was beyond the range of the Canal Zone-based Wellingtons, though they could still reach it from Malta. The heaviest blows were struck by a number of daylight-to-dusk attacks by the Liberators and Halifaxes, the targets being ships and harbour installations. Outstanding among the many raids made by R.A.F. and U.S.A.A.F. Libs. on Benghazi were a series of three made on September 16 and 22. On the morning of the first raid the Liberators set off from near Cairo and flew in close formation on their 600-mile journey to the target.

At midday, still flying in perfect formation, they sailed out of the sun across Benghazi harbour, where a number of sizeable ships were off-loading on to ‘George’, ‘Harry’, and ‘Johnny’, wrecks which had been concreted in and had long served as the main unloading jetties. The Liberators pattern-bombed; several vessels received direct hits and burned, and the bomber crews as they left the scene saw one vessel suddenly explode with great force, flinging debris high above the harbour. All the Liberators returned safely."

Thanks for all the responses.
First, I am reviewing the book and will wait until I finish it completely before identifying it.

Second, I tend to agree with Will "'Neil, although the value of radar flooding, as Will knows, is not trivial--even with the older non-X band radars in use in 1942. Submarines go slower underwater and thus reengagements, especially in a wolf pack fight or in transit to a wolfpack fight, are negatively affected by radar flooding. Submarine sensors pick up it up and then decide to submerge, thus they go slower underwater and run down their batteries as well. Tactical results yes, operational results....mmmmmm?

I agree overall with the argument that the author overstates his conclusion that the war might have ended earlier. Contingency is part of history, but I agree that many other things had to happen too and the invasions were far more dependent on assault shipping than on merchant shipping of goods, food, and raw materials. Assault shipping assignment, positioning, and prioritizing was among the most difficult problems the Allies faced.

Overlord was never going to happen earlier than it did, Battle (or rather campaign) of the Atlantic notwithstanding. My evidence on that score is Jim Lacey's _Keep From All Thoughtful Men_ which argues materially the US could not do it. Even if manpower had been reprogrammed from building bombers to build more ships, more shipyards too would have had to have been built, they were maxed out, both in US and Canada. Finally, it was the equipment to PUT on these ships and the trained US divisions that were really the long poles in the tent for Overlord and cutting back on lend lease was not option except for perhaps China but that was a drop in the bucket.

In the end, a more efficient and rational prosecution of the war in the Atlantic might have saved more lives on the Allied side, but it would not have done much else. I await Will's corrective response.

vr, John T. Kuehn

Dr. Kuehn,

The main use of ASV radar on Coastal Command planes in the 1940-to-early 1942 period was not to find submarines.

It's prime role was allowing maritime patrol aircraft to find convoys in bad weather and to home on Coastal Command radar beacons at home bases in 1941-42.

These beacons were code named "Mother"and, IIRC, "Home to Mother" was a standard Coastal Command reply saying "returning to base."


British ASV radars
prepared by Emmanuel Gustin

"...The radar was not yet ready for service, however. Development was delayed by what Dr E.G. "Taffy" Bowen, head of the airborne radar group, described as "totally inadequate resources and virtually no administrative back-up." Finally, two antenna configurations were developed for ASV radar. One used a dipole transmitting antenna with a reflector to give a broad beam in the forward direction. The two receiving antennas were on the aircraft's wings, and their polar diagrams overlapped. The direction of the target was determined by comparing the signals from the two receivers, displayed together on a cathode-ray tube, one to the left of the (vertical) baseline and the other to the right. If the target was on the right then the right receiver gave the stronger signal. The vertical timebase indicated the distance to the target. This system gave a range of 10 miles on a 1000 ton ship, and up to 40 miles on a coastline with steep cliffs.

This was introduced as the first ASV radar (Mk.I), and installed on the Hudsons of Coastal Command. By the end of 1940 it was fitted in 24 Hudsons and 25 Sunderlands. About 200 sets were produced. Experience with it was not very good. The radar was unreliable and new equipment, and the manufacturing standard of many components left a lot to be desired. The problems of maintenance and training were enormous. Its usefulness and popularity were increased by Sqdn. Ldr. Lugg, who installed a 1.5 meter beacon at Leuchars. ASV Mk.I then was, at least, useful navigation equipment.

ASV Mk.I was not intended to detect submarines, but after an enquiry from admiral Somerville in late 1939 test were conducted with one of the Hudsons of No.220 Sqdn and the submarine L 27. It was demonstrated that, flying at 1000 feet, the submarine could be detected at 3 miles, broadside on, and this under experimental conditions --- that means that the crew of the Hudson knew exactly where the submarine was. Further tests revealed that when flying at 6000 feet, the range was increased to 6 miles.

A notable improvement was achieved with what called Long Range ASV. LRASV was based on the second antenna configuration developed. It was a sideways-looking system. The transmitter was an array of ten dipoles, installed in five (later reduced to four) pairs on top of the fuselage of the aircraft. The receiving antennas were Sterba arrays, fitted to the sides of the fuselage. Because the transmitter array was a dipole array 18 feet long and the two receivers were arrays 12 feet long, a much better resolution and range could be achieved. The first installation was on a Whitley bomber, in late 1939. LRASV had a range 2.5 times better than the forward-looking system; it could detect submarines at 10 to 15 miles.

Developed at the Royal Aircraft Establishment at Farnborough in early 1940, ASV Mk.II differed from Mk.I mainly because it was properly engineered, and therefore much more reliable. Although called a 1.5m radar, it actually used 1.7m (176MHz). Range was up to 36 miles. The minimum range was about a mile. Several thousand sets were built, and installed in Hudsons, Sunderlands, Wellingtons, Beauforts, Warwicks, Whitleys, Liberators, and other Coastal Command aircraft. ASV Mk.II was used with both the forward-looking and the sideways-looking LRASV configuration, production being divided approximately equal. Only the LRASV was useful against submarines.

The first success was recorded on 30 November 1940, when a Whitley Mk.VI equipped with ASV damaged U-71 in the Bay of Biscay. By mid-1941 the ASV radar had increased daytime attacks on U-boats by 20%, and made nightly attacks possible.

However, night attacks were generally ineffective, for the simple reason that the aircraft crew could not see the submarine. The radar guided them to a mile of the submarine, but not closer. On 21 December 1941 an ASV-equipped Swordfish made the first successful night attack on an U-boat, but such remained exceptions."

And also see a photo of a Coastal Command Liberator with the ASV Mark II in the sideways-looking LRASV configuration I posted on social media --


H-War readers interested in this debate about the air gap, very long range aircraft, and the Battle of the Atlantic will probably learn a fair amount--as I did--by reading a long article by Christopher M. Bell: Air Power and the Battle of the Atlantic: Very Long Range Aircraft and the Delay in Closing the Atlantic “Air Gap." It is easy to find online; I downloaded it from Academia after a free registration there. It discusses most, if not all, of the issues that we have brought up here, and adds information about the escort carriers which were probably a better solution to the problem than Liberators. I was not aware that because the Royal Navy was desperate for any carriers that the US-built escort carriers were diverted, for many months, and not used for convoy protection. The roles played by Churchill and others are discussed, and the heroes and villains of many accounts turn out to have played other parts.
Jonathan Beard

Regards the issues of this thread, namely the issues RAF bomber Command not letting B-24's into RAF Coastal Command in 1942 and the non-filling of the North Atlantic "Air Gap" by centimeter (cm) band radar equipped Liberators,
I'm going to point out the following sources to show there were in fact enough such 10cm Liberators conducting ASW in the summer of 1942.

They were not allowed to be there thanks to the wartime roles and missions bureaucratic politics of US Navy Admiral Ernest J. King.

See here:

Army Air Forces Antisubmarine Command

"AAF Antisubmarine Command organizes
In May 1942, General Arnold, Commanding General of the AAF, proposed to Admiral King, the Chief of Naval Operations, that the AAF establish a "coastal command", similar to RAF Coastal Command, operating "when necessary, under the proper Naval authority."[6] That same month saw both a new high in sinkings by U-boats and a shift in their attacks from the Atlantic coast to the Caribbean Sea. In response, the AAF established the Gulf Task Force, with elements of Third Air Force augmenting I Bomber Command, at Miami, Florida[note 2] to augment the Gulf Sea Frontier.[7] The command situation had only worsened, with two air forces, two navy sea frontiers, and two army defense commands, with differing areas of responsibility, all involved in aerial ASW with ad hoc command relations and separate administrative and operational command arrangements.[8] Later in the month, the War Department requested General Arnold to reorganize I Bomber Command to fulfill the requirements of ASW air operations, either in support of, or in lieu of, naval forces to protect Allied shipping.[9]

Disagreements between the Army and the Navy over command relationships delayed activation of the command until October 1942. The activation of the single Army Air Forces Antisubmarine Command at New York City to control all Army Air Forces units conducting antisubmarine warfare reflected the Army's desire for a single mobile force.[1] The command drew its personnel and equipment from I Bomber Command, which was simultaneously inactivated.[10] In November 1942, the command's units were organized into two wings, reflecting the Navy desire that forces in a sea frontier be unified under a single command.[11] The 25th Antisubmarine Wing, Located in New York City was responsible for patrols off the Atlantic Coast, while the 26th Antisubmarine Wing in Miami, Florida conducted operations in the Caribbean and the Gulf of Mexico.[12][13]"

and later at the same URL --

"Transfer of mission to the Navy
Disagreements between the AAF and the Navy over command of long range aviation units engaged in antisubmarine warfare and of whether those forces would best be employed (offensively or defensively) continued into 1943, and in June, the AAF agreed that "The Army is prepared to withdraw Army Air Forces from anti-submarine operations at such time as the Navy is ready to take over those duties completely."[31] In July, plans were made for 77 of the command's Consolidated B-24 Liberators equipped for antisubmarine warfare to be exchanged for an equal number of B-24s assigned to the Navy. Navy squadrons relieved the 479th Group in October, and its personnel and planes were transferred to Eighth Air Force to form a pathfinder unit. By mid November, the 480th Group had been relieved and was on its way back to the US. Its two squadrons were inactivated in October and their personnel assigned elsewhere. The majority of the command's squadrons were redesignated as bombardment squadrons and transferred to Second Air Force, while the 25th and 26th Wings were disbanded.[12][32]"

And also see here:


Abstract --

"This historical review traces the development of the role of the Army Air Corps in
antisubmarine warfare. Pre-war plans exempted the Air Corps from this duty. Despite
lack of training and equipment, the Air Corps contributed significantly to the defeat
of the submarine threat. In defeating this threat, the Air Corps had to first battle
the Navy's strategy of using airplanes to escort convoys. Before being relieved of
antisubmarine warfare duty, the Air Corps had proved the necessity of using the
airplane in an offensive role to search and destroy submarines."

MAJ. Torres' 1985 paper has maps of the operating areas together with their dates of operation, of the MIT 10cm radar equipped B-24 Liberators of the US Army Air Forces Antisubmarine Command.

Hint: Despite being available to fill the North Atlantic Air Gap in 1942, 10cm radar equipped USAAF B-24 were -NEVER- based in Iceland in large part thanks to Adm Ernest King's wartime "Roles and Missions" budget politics.

Chapter eight of G. Pascal Zachary's "ENDLESS FRONTIER, Vannevar Bush, Engineer of the American Century" explains that Adm King nearly lost the role and mission of long range land based anti-submarine aircraft patrols in 1942-1943 to General Hap Arnold's USAAF, and the MIT Radiation Laboratory, because the USAAF used MIT's 10 cm air search radars on B-24's to hunt U-Boats.

The USN's Bureau system saw centimeter band radar fall between the stools of the Bureau of Ordnance and The Bureau of Aeronautics, so the USAAF exploited this to build an ASW empire at the USN's expense because it was the patron of microwave radar in the US Military after the U.K.'s "Tizard Mission."

To say that this did not sit well with Adm King is to state that water is wet!

During this 1942-1943 period Adm King created "10th Fleet" to do ASW with Ultra intelligence and operational analysis in the Atlantic and more importantly Adm. King centralized radar development of the COMINCH office outside the Naval Bureau system that had lost the long range ASW aircraft mission to the USAAF.

Using his influence with Pres. Roosevelt, King took control of 10 CM radar production and battled back to fully possess the long range land based air patrol mission by the end of 1943.

The accepted historical narratives of the Battle of the North Atlantic state that only a few 10cm B-24 made the difference in defeating the U-Boats in 1943.

The man standing in the way of that happening in 1942 wasn't Sir Arthur Harris of RAF Bomber Command. It was the US Navy's Admiral Ernest J King.