BOMBER OFFENSIVE

THE ASSAULT FROM THE AIR

In earlier chapters of this book the bombing of Warsaw, the London Blitz, the devastating German air raids on Coventry, Clydebank, Plymouth and other targets have been described in the context of their tactical use as part of campaigns to capture Poland and Britain. The Allies took a different view of air power from that adopted by the Luftwaffe in general, and by Goering and Hitler in particular. To the Allies, air power was a strategic weapon aimed almost totally at the destruction of the means of production on the one hand, and of enemy towns, cities and morale on the other.

From the beginning, the Luftwaffe was designed as a weapon to achieve massive conquest in the shortest possible time - it was a Blitzkrieg weapon. Hitler's burgeoning ambition and proliferation of active fighting fronts stretched the Luftwaffe badly, as did its severe losses in the Battle of Britain, with the result that, after the initial successes in Russia in 1941, German air power began to wane. One of Hitler's least far-sighted directives had, in 1940, ordered the abandonment of work on all new aircraft types that could not be in service by 1942 on the grounds that "they would not be needed after the war", and, as a result, development of new aircraft types was "too little and too late".

The British had quite early in the war - in August 1940 in fact - proved false Goering's notorious boast that Berlin would never be bombed, and throughout 1941 had maintained constant harassment of Germany by night, albeit on a relatively small scale by comparison with later raids. By spring 1942, the British build-up of bombers, and the development of longer range aircraft, had reached the point where large scale raids could be mounted, and on May 30th 1942, the RAF delivered its first "1,000 bomber raid" on Cologne. In fact, although there were actually just over 1,000 aircraft, many of them were obsolete, and losses were quite high. Cologne was left ablaze and the propaganda effect on the populations of both Britain and Germany was substantial. There followed a rapid series of night carpet bombing raids against the major strategic cities of the Reich - Essen, Dortmund, Leipzig, Hamburg, Berlin - in which civilian populations were hit as hard as German industry. But the assault was not against cities alone.

As longer range four engined aircraft such as the Stirling, the Halifax and the Lancaster became available, more ambitious heavy raids on specifically industrial targets were undertaken. Important centres of production like the steelworks of the Ruhr were hit repeatedly, and in May 1943, Barnes Wallis' famous bouncing bomb was used effectively against the Moehne, Eder and Sorpe dams by 617 Squadron RAF, led by Wing Commander Guy Gibson - the raid portrayed in the British motion picture The Dam Busters , made early in the 1950s.

Once the USA was into the war, an argument developed between the US 8th Air Force, formed and led in Britain by General Carl Spaatz, and RAF Bomber Command, under the command of Air Chief Marshal Sir Arthur (Bomber) Harris. The US aerial bombardment strategy was based upon the assumption that heavy bombers carrying sufficient guns could defend themselves against attacking fighters in daylight, and that daylight bombing with pinpoint accuracy was therefore possible. If this were correct, there was obviously much to commend the US approach, as it would reduce to a minimum the impact upon civilian populations and increase the effectiveness of every bomb. Spaatz also rejected Harris's contention that carpet bombing of German cities would break German morale; he argued that if German bombing had failed to bring London to its knees, there was no justification for assuming that Berlin or Hamburg would give in any more easily.

Sir Arthur Harris believed that there was no way in which heavy, relatively slow and largely unmanoeuvrable bombers could defend themselves effectively without fighter cover - a point which to British eyes had been substantially proved by the Luftwaffe's failure in daylight raids over Britain - and that, since no fighters existed with long enough range to fly to Germany and back, the only practical approach to strategic bombing was large scale carpet bombing at night of the areas in which large production and military installations were known to exist. He was also confident that bombing of the cities would result in the civilian population of Germany bringing massive pressure to bear on Hitler for an end to the war.

Since neither side wanted to give, and because there was no way of knowing for sure who was right without testing the hypothesis, a compromise was reached in September 1942 by which the US 8th Air Force attacked by day, and the RAF flew by night.

The American crews flew B-17 Flying Fortresses and B-24 Liberators - each bristling with pairs of 0.5 calibre Browning machine guns from hydraulically controlled turrets pointing in almost every direction. The B-17, originally designed in 1934 and first flown in 1935, operated during the Second World War in three principal versions, the B-17E, the B-17F and the B-17G. The majority of operational aircraft by mid 1944 were of the last type, distinguished by its unusual "chin" gun turret, of which 8,680 were built. The B-17 typically carried a crew of nine, could carry a 10,500lb bomb load, and was fitted with the remarkably accurate Norden bombsight. If it got through to the target, which a significant proportion did, it was able to do tremendous damage with its pinpoint bombing. But, in the early days of the daylight bombing offensive, before suitable fighters were available to provide long range escort, German Messerchmitt 109 and Focke-Wulf 190 fighters were able to shoot down large numbers of the close formations of American bombers. In 1943, the Luftwaffe fighters even used successfully the tactic of bombing the formations from above.

In August 1943, the US Eighth Air Force began the process of attacking the Luftwaffe production line as a means of reducing the available German air power to combat "Overlord" when it came. On August 17th, 376 Eighth Air Force aircraft bombed the aircraft factory at Regensburg and the massive ball-bearing production plant at Schweinfurt. Ball-bearing production was a key to the entire war production programme, and Albert Speer, Germany's Minister of Armaments Production, was quoted after the war as saying that if the pressure on ball-bearing production had been maintained, the war production machine would have ground to a halt in only four months. But the raid on Schweinfurt was very expensive indeed in both men and machines. Sixty bombers did not return to their bases in England, and that meant that over five hundred highly-skilled aircrew were lost to the war, either killed or taken prisoner. Not until long-range Mustangs with drop-tanks were available could the massive raids on the more distant parts of Germany continue. In fact, in October 1943, the loss of 153 US bombers in one week caused the cancellation of all raids without fighter escort.

The US raids were not all based in England. Just over two weeks before the raid on Schweinfurt, a force of 178 Consolidated B-24 Liberators took off from Libya to raid the Rumanian oilfields at Ploesti, the principal source of Wehrmacht fuel. This raid was enormously hazardous, stretching the range of the Liberator to the absolute limit, and requiring the crews to fly most of the 1,500 mile mission over German occupied territory beset by attacking fighters. Many of the force did not reach their target, but those that did caused great damage to the German war effort. Of the 1,733 men who flew the mission, 446 were killed. Only 33 of the original 178 aircraft flew in action again - many of those that managed to get back to North Africa were not economically repairable.

After the end of 1943, the invention of drop tanks made long range escort of the US bomber formations by the new Mustang fighter entirely routine and bomber losses fell sharply as the damage inflicted on the Luftwaffe by the Mustangs rose. The Mustang, with a range of 850 miles, was the longest-range fighter of World War Two, and performed many roles successfully - Group Captain Leonard Cheshire, VC, of the RAF even using one in his pioneering of pathfinder marking of night targets for the RAF bomber forces.

The biggest problem that had afflicted RAF night bombing in the early part of the war was the difficulty of finding the target. In 1940, investigations had shown that two-thirds of the RAF crews on a raid had not bombed within five miles of the target. This was solved to a large extent first by a guidance device known as "Gee", then, from March 5th 1943, by a more sophisticated radar installation codenamed "Oboe". A Pathfinder Force was formed of crack crews, usually flying Lancasters, which were fitted with an even more effective radar known as "H2S". Their task was to precede the main force to the target and bomb it accurately with coloured flares to show the bomb-aimers of later aircraft where to target their bombloads.

The techniques of carpet bombing by night became gradually more effective, and all pretence of seeking military targets alone was abandoned after the Casablanca conference sanctioned the use of all-out strategic bombing of Germany. The RAF, in four nights between July 24th and August 3rd 1943, killed an estimated 33,000 people in Hamburg by creating a firestorm, a phenomenon previously known only in theory. Most of the dead were suffocated by the lack of oxygen resulting from the colossal and unimaginably intense fires that engulfed the city. Known to the German population, understandably, as Die Katastrophe , the raids on Hamburg stirred fierce resentment against the RAF, whose crews were known as terrorflieger and were treated roughly by North German townspeople if they were forced to bale out over the cities. In the first eight months of 1943, 11,000 tons of bombs were dropped by the RAF on Hamburg, 8,000 tons on Essen, 6,000 tons each on Duisburg and Berlin, and 5,000 tons each on Dusseldorf and Nuremberg.

Against these raids, the Germans developed a guidance system for its night-fighters which was known as the Wurzberg , a radar which enabled the night fighter controller to talk his squadrons on to the British formations, and a low-frequency radar called Freya , which acted as an early warning system. To combat these radar devices, which were becoming progressively more effective, British scientists came up with a delightfully simple idea codenamed "Window" - nothing more than thousands of strips of metal foil dropped from the formations of aircraft, which, as it fluttered thousands of feet towards the ground provided the German controllers with thousands of false echoes and obscured the real ones that represented the aircraft. By pursuing a non-committal course until after the "Window" was dropped, the bomber formations were able to conceal their real target from the night fighters and flak gunners until ground reports of the attack gave their positions away.

As 1944, the year of "Overlord" approached, the Allied air offensive was stepped up, partly to maintain the pressure on armaments production and civilian morale, more to cause the Luftwaffe to pull back such reserves as it had from the Atlantic Wall and the defence of the Channel coast to Germany and the defence of the cities. Between January 1st and June 5th 1944, the day before D-Day, the US daylight marauders and the RAF night bombers between them delivered 102 major attacks on German cities. Berlin was almost destroyed by 17 fierce raids; Braunschweig was next in the league of destruction with 13 raids; Frankfurt received eight raids and Hanover five. Many other cities were attacked - Leipzig, Magdeburg, Duisburg, Essen, the other cities of the Ruhr and North Germany. Even Vienna was raided in March.

By the spring of 1944, the Luftwaffe was severely depleted, its means of production were being attacked almost daily, and, most important of all, its fuel supplies were reaching crisis point. Much of the credit for this acute shortage of fuel was due to the success of a campaign launched at the beginning of April 1944 by General Spaatz against Germany's sources not only of natural fuels, but also of the synthetic fuels that her scientists had learned to manufacture. We have already described the previous year's assault by Liberators on the oilfield at Ploesti in Rumania. By April 1944, the US Army Air Force was established in Italy, at Foggia, and was in a much stronger position to attack the oil-producing area at shorter range and with far greater chances of success.

On April 4th, a raid from Foggia on Ploesti by 230 bombers did far more damage to oil-field installations than had the previous raid, and the US arimen followed it up with attacks on refineries and storage depots in Bucharest, Budapest and Vienna, and with raids on the Danube ports and on the convoys of barges that transported fuel along the Danube. Between February 1944 and the end of June 1944, the amount of Rumanian oil and refined petroleum reaching Germany was reduced by 80 per cent, from 200,000 tons a month to 40,000 tons per month.

German synthetic fuel sources were hit even harder. On May 12th 1944, just under 1,000 US bombers attacked synthetic fuel plants at five separate targets - Brux, Lutzkendorf, Zeitz, Bohlen and Leuna. Just over two weeks later, on May 28th and 29th, those same targets were attacked again, and, in addition, the US Army Air Force destroyed the vital coal hydrogenation plants at Politz in Pomerania. The effect was devastating to the German war effort. From producing 181,000 tons of aviation fuel in March 1944, slightly more than the severely rationed Luftwaffe actually used, the Germans were down to a production of 10,000 tons in September, when they used 60,000 tons, and never again managed to get fuel production up either above 49,000 tons in a month, or up to the rate of consumption. The attacks on the fuel supplies were the death knell of the Luftwaffe .

Thus, when General Eisenhower was briefing his troops for "Overlord", the long-awaited Allied invasion of Normandy, he was able to tell them, with some truth, that if they saw a warplane overhead, they could regard it as friendly. That this was so was due to a large extent to the success of the air offensive.