Leading Up to D-Day
Courtesy of Fox Photos via Getty Images.Radar played an instrumental role in preparing and carrying out the D-Day invasions, then supported the push into occupied France.
I. U-Boat Warfare and the Battle of the Atlantic
“The overwhelming military problem confronting Britain... was the U-boat war in the Atlantic... to the extent that an area bombing offensive against the German homeland could not possibly produce decisive results either in 1942 or 1943, it entailed the unacceptable risk of British defeat at the behest of the U-boat.”
- M. Kirby and R. Capey, Lancaster University, for the Journal of the Operational Research Society, 1997
German U-boats were sinking millions of tons of Allied supplies and ships, and was a threat that needed to be neutralized.
Coast Guard Sinks Nazi U-Boat - Coast Guardsmen on the deck of the US Coast Guard Cutter Spencer watch the explosion of a depth charge which blasted a Nazi U-boat's hope of breaking into the center of a large convoy. Sinking of U-175, April 17. 1943
Courtesy of Corbis via Getty Images.
Sea Convoy - November 15th, 1941: A large convoy of ships seen from a US Navy flying boat patrolling the North Atlantic.
Courtesy of Keystone/Getty Images.
Airborne radar was first used to fight the deadly German U-boats.
“The new factor introduced by [ASV, Air Surveillance] radar was that aircraft could now spot them on the surface in bad weather and at night. The aircraft might arrive at any time with no warning of approach and the submarines would be forced to submerge. This alone would seriously limit their mobility and the distance to which they could penetrate into the Atlantic. The task of the aircraft, therefore, was simply to hunt the submarines at night and keep them submerged as much as possible.”
- Edward George "Taffy" Bowen in his book Radar Days, Welsh Physicist, assistant to Robert Watson-Watt
However, the inconsistent use of radar meant it did not have a significant impact on U-boat warfare until late 1941.
Courtesy of Edward "Taffy" Bowen in his book Radar Days.
“The failure of the attacks during 1940 can be put down to many factors, but in simple terms it was due to the need for a very protracted training period... their problems were compounded by the poor serviceability of ASV Mk I, the lack of test equipment and the total absence of training facilities.”
- Edward George "Taffy" Bowen in his book Radar Days, Welsh Physicist, assistant to Robert Watson-Watt
Original wartime caption: The Fortress II, famous four-engined bomber built by the U's Boeing Aircraft Company, which was delivered to this country by the Lease-Lend Agreement, is now flying with the RAF Coastal Command. The 22-ton aircraft costing £75,000 is engaged there on convoy escort work and anti-submarine patrol. The Fortress II in flight. Picture issued 1943.
Courtesy of Royal Air Force Official Photographer via Imperial War Museums.
“In November 1941... [it was] concluded that aircraft would be able to surprise U-boats if they used cloud cover to hide in and used ASV [radar] alone to locate enemy submarines...The higher level of surface attacks when U-boats had been detected in poor weather or at night, that is by ASV rather than visual means was notable.”
- Prof. John Buckley, Professor of Military History at the University of Wolverhampton
“Radar-equipped aircraft could find submarines at night, but during the final run-in the pilot and the bomb aimer could not see the target... Leigh proposed mounting a searchlight in the search aircraft which would then make a low-level run on a surfaced submarine, illuminate it and drop depth charges with nearly the same accuracy as in daylight...
Pilots and Crew Discussing Mission Results - 11/18/1943: Air combat intelligent officers, Lt. Leslie McCreath, Jr. of Scranton, PA (back to camera) and Lt. Curtis B. Brooks, of Providence RI (far right) quiz a plane crew after a successful attack on a U-boat. Describing the results of their mission to the officers, below deck on a US flat top in the Atlantic are (left to right) C.T. McKinley, turret gunner, Lt. S.F. Doty, pilot, Ensign J. Horn, and R.E. Pollock, radioman.
Courtesy of Getty Images.
“The combination of the Leigh Light and ASV radar was extra-ordinarily effective and had such a demoralizing effect on the German submarine crews that they actually switched their routine.”
- Edward George "Taffy" Bowen in his book Radar Days, Welsh Physicist, assistant to Robert Watson-Watt
Overall, the consistent modifications of radar for U-boat warfare demonstrates how radar was developed to support the war effort.
The Losses from the Battle of the Atlantic
“The Battle of the Atlantic was a momentous struggle... 2603 Allied Merchant ships were sunk, carrying thousands of invaluable men and millions of tons of food and raw materials... out of nearly 1200 German submarines... 65 percent were irretrievably lost... Forty thousand men were recruited into the German Submarine Service; no less than 28,000 perished and a further 5000 were taken prisoner.”
- Edward George "Taffy" Bowen in his book Radar Days, Welsh Physicist, assistant to Robert Watson-Watt
Sinking Allied Tanker - An allied tanker crumbles under the heat of fire after being torpedoed in the Atlantic Ocean by a German submarine, 1942.
Courtesy of Corbis via Getty Images.
American Plane Bombing German Submarines - A series of small eruptions in the water show the path of an air attack on German Submarine U-134, John T Hitchcock piloted the VP-201
Courtesy of Corbi via Getty Images.
German U-Boat Under Attack - A surface German U-boat is under attack by American B-25 Mitchell and B-24 Liberator bombers. A few minutes after this photograph was taken, the vessel had been sunk.
Courtesy of Getty Images.
“By 1944, the Loran [radar] network covered more than one fourth of the world, including most of the contested area. From the air, radars on U.S. planes sought out enemy ships. On the water, U.S. fleets moved in formation by radar, found the enemy by radar, watched for enemy planes by radar...
“Radar provided a great bridge stretched across the Atlantic. And under this radar cover the supplies poured over to Europe.”
- T. A. Saad, Electrical Engineer, Theoretical/Microwave Division of the Rad Lab
“The enemy has deprived the U-Boat of its essential feature- namely the element of surprise- by means of radar. With these methods... he has conquered the U-Boat menace. The scientists who have created have been called the saviors of their country.”
- Adm. Doenitz, Supreme Commander of the German Navy during World War II
II. The Influence of the Bombing Campaigns on D-Day
For the prospect of an invasion to be pursued, the Allied military leaders were adamant that after the U-boat threat was neutralized, Germany's economic, industrial, and military structure had to be debilitated.
“The 'Pointblank' directive of June 1943 [after the Casablanca conference]... launched a Combined Bomber Offensive against Germany in cooperation with the US Eighth Air Force. The first draft of the directive stated that the immediate and primary focus of attack for the combined bomber forces should be 'enemy fighters in the air and on the ground'.”
- M. Kirby and R. Capey, Lancaster University, for the Journal of the Operational Research Society, 1997
Bombing a Focke-Wulf Factory - Aerial view of a squadron of American Boeing B-17 Flying Fortresses from the US 8th Air Force Bomber Command, as they fly away from a bombing run at a Focke-Wulf aircraft plant, in flight above Marienburg, Germany (later Malbork, Poland), October 9, 1943.
Courtesy of Underwood Archives/Getty Images.
With this objective determined, a day-and-night bombing campaign was established.
“In radar itself there had been a distinct change in emphasis; it was no longer regarded as a purely defensive weapon and serious consideration was given to how it could be used in offensive roles.”
- Edward George "Taffy" Bowen in his book Radar Days, Welsh Physicist, assistant to Robert Watson-Watt
Radar enabled this campaign because bombing runs could be flown in darkness and despite poor weather.
“Daylight bombing was [a] very, very dangerous mission, you'd fly out there and the German fighters would see you and they shot you down and guys were getting killed. It was a horrible mission...[but] flying at night... [the Luftwaffe] have no idea [where you are]... They don't have radars in the fighters.”
- Lt. Col. Randall DeGering, USAF (ret.)
Vertical photographic-reconnaissance aerial taken over the railway yards at Saintes, France, following an attack by aircraft of Bomber Command on the night of 23/24 June 1944. Almost every building in the yard is either destroyed or severely hit, and every line cut or torn up.
Courtesy of No. 542 Squadron RAF via the Imperial War Museum.
“[In further preparation for Operation Overlord following the Operation Pointblank, it was decided] that concentrated, precise attacks upon railway targets scientifically could probably produce a degree of disruption and immobility which might make all the difference to the success or failure of the long awaited invasion of France.”
- Sir Arthur Tedder, Overall Air Commander in 1943, as quoted by M. Kirby and R. Capey in the Journal of the operational Research Society
Leading up to D-Day, radar-guided bombing was used to draw the Germans away from Normandy and limit German mobility.
A B-17G of the 100th Bomb group bombing beach defenses near Boulogne, as part of the 'Overlord' deception plan, June 5, 1944.
Courtesy of the United States Army Signal Corps via the Imperial War Museum.
A general view of Caen showing the extensive damage caused by Allied bombing, July 9, 1944.
Courtesy of Major Stewart, No. 5 Army Film and Photo Section, Army Film and Photographic Unit via the Imperial War Museum.
Avro Lancasters carpet bomb a road junction near Villers Bocage, Normandy, France through which the 2nd and 9th SS Panzer Divisions were expected to move to carry out an attack on the junction of the British and American armies. The daylight attack, by 266 aircraft of Nos. 3, 4 and 8 Groups, was carried out at 4,000 feet to ensure that the target indicators dropped by the Pathfinders were seen and 1,100 tons of bombs were dropped with great accuracy.
Courtesy of the Imperial War Museum.
“The invasion of the European mainland began at about midnight on June 5. Since the moon was clouded over, bombing of coastal defenses was done with the aid of H2X, with [the Microwave Early Warning Radar] watching. After the bombing, the invasion fleet went over...
“At 20 minutes before the landing, Oboe [British Beacon Radar Bombing] went over to hit coastal batteries. In the invasion fleet, SO, a light ship-borne search radar, went over in landing-craft, to stand offshore and help direct the landings. In the Troop Carrier planes, S and X-band beacons went over as standbys to mark dropping zones for parachutists... And in the big landing crafts, thirty-nine 584's went over to protect Allied forces from strafing.”
- T. A. Saad, Electrical Engineer, Theoretical/Microwave Division of the Rad Lab
Consolidated B-24H Liberators of 486th Bombardment group, US Eighth Air Force, flying over part of the Allied invasion fleet gathered off the Normandy coast, June 6, 1944. They were part of a force dispatched on the morning of D-Day to bomb villages which had access roads to the beachheads running through them.
Courtesy of USAF photographer via the Imperial War Museum.
Operation Overlord: The Normandy coast: radar image of a bomber from the US Air Force in a distance of about 3000-4000 meters. June 1944. The mouths of the rivers Orne and Vire and the location of some cities are shown. Note battleships and cruisers shooting position parallel to the coast and the cloud of vessels between the Orne and Vire, less visible near Utah beach.
Courtesy of Galerie Bilderwelt/Getty Images.
Screen of one of Luis Alvarez's S Microwave Early Warning radars captured the D-Day invasion on June 6, 1944.
Courtesy of the MIT Museum/Robert Buderi.
“The big question was what had happened to the German Air Force? We knew we had defeated the Luftwaffe, but even half an air force would have tried to bomb those parts in southern England crowded with landing craft of all kinds… Instead of that, no attacks had been made on the installation prior to D-day, nor on the boats going across the Channel… nor on the beaches after the invasion…Had our plans for 'round-the-clock' bombing of Germany borne fruit? We needed no further proof.”
- Gen. Hap Arnold after the success of June 6, 1944
III. Fighter Control Squadrons
“The Army had this...extra group that flew airplanes called the Army Air Force and the Army Air Force guys flew the fighters and they knew how to attack other fighters, but they didn't have any way of knowing where they were...a Signal Corps guy said 'We've just got this new invention called radar, so how about if we pair together, we'll use our radar, you'll use you fighters, and that's how we will control fighters going in and attack the bad guys.'...So they built these fighter control squadrons.”
- Lt. Col. Randall DeGering, USAF (ret.)
Direction Finding Truck
Courtesy of DeGering/Reproduced from History, 15th Fighter Control Squadron, March-May 1944.
Fighter Control Squadrons use mobile radar to guide fighter planes through all the theaters in the war to help the troops.
“We gathered that in a seaborne invasion of hostile shore, the best time for counter-attack is on the first night, or in the early stages of build-up. Air activity at night could be difficult to counter, so a necessary defense for the invaders would be effective night fighter protection. Mobile GCI [Ground Control Interception] units were to be landed close behind the initial waves of the attack, and to be operational in support of the beachhead on D-Night... On the night of D-Day plus one [two] enemy aircraft were shot down - the first GCI-controlled interception from the American beachhead.”
- Fl. Lt. E.H. "Ned" Hitchcock, Electrical Engineer officer, RNZAF, in C. Latham and A. Stobb's book Radar: A Wartime Miracle
Direction Finding Operator
Courtesy of DeGering/Reproduced from History, 15th Fighter Control Squadron, March-May 1944.
“That whole time, all the radars that were being used...they were mobile, they were on trucks and they would drive out, set them up, and talk to fighters, tell them where to go. And as the war was moving closer and closer to Germany, they would keep relocating.”
- Lt. Col. Randall DeGering, USAF (ret.)
“15121 BDS (Base Defense Sector) was one of five mobile GCI unites which went to France in 1944 as part of the RAF's 2nd Tactical Air Force... Its function was to provide air cover over the battlefield and tactical air support for the armies fighting on the ground.”
- Gerald N.S. Taylor, Radar Mechanic, in C. Latham and A. Stobb's book Radar: A Wartime Miracle
SCR-270 mobile radar.
Courtesy of DeGering/Reproduced from Terrett, The Emergency, 126.
RPReplay_Final1704654903.movFootage of a PPI radar screen and operator. Excerpt from the mini-documentary Radar History: Rad Lab and Schenectady Work
Courtesy of EdisonTech Center.
“By the time autumn [1944] came and the ground troops' attack had slowed, 584 and MEW were teamed in a new activity. In combination, they guided the fighter-bombers, not just in control of air-to-air combat, but more importantly, in control of air-to-ground action. This was very helpful in the weather-bound Battle of the Bulge.”
- T. A. Saad, Electrical Engineer, Theoretical/Microwave Division of the Rad Lab
IV. Radar, The Crucial Weapon of the War
“For those of us who lived and fought through those desperate days it was indeed a miracle... radar in its many roles contributed so much to the achievement of ultimate victory.”
- Sir Edward Fennessey, Electronics Engineer under Watson-Watts, in C. Latham and A. Stobbs' book Radar: A Wartime Miracle
“New radars were being created- not fundamentally new, but new tactically. By summertime, the CXBK, a new experimental X-band ASV radar, was flying. When pictures of its scope presentations, with their clearly defined shorelines, reached England, an RAF dignitary said "Gentlemen, this is a turning-point in the war."”
- T. A. Saad, Electrical Engineer, Theoretical/Microwave Division of the Rad Lab
Courtesy of G.H. Davis, 1946, in their available resolution.