Tag Archives: Bomber

18 April 1942

A North American Aviation B-25B Mitchell medium bomber revs its engines, awaiting teh signal to launch from the flight deck officer. (U.S. Air Force)
A North American Aviation B-25B Mitchell medium bomber revs its engines, awaiting the signal to launch from the flight deck officer. (U.S. Navy)
With flight deck personnel dropping to the deck to avoid its turning propellers, A north American B-25B Mitchell medium bomber starts its takeoff roll aboard USS Hornet (CV-8), 18 April 1942. (U.S. Navy)
With flight deck personnel dropping to the deck to avoid its turning propellers, a North American B-25B Mitchell medium bomber starts its takeoff roll aboard USS Hornet (CV-8), 18 April 1942. (U.S. Navy) 
Fleet Admiral William F. Halsey, United States Navy
Fleet Admiral William F. Halsey, United States Navy

18 April 1942: Task Force 16, under the command of Vice Admiral William F. Halsey, Jr., U.S. Navy, approached the Japanese islands on a daring top secret joint Army-Navy attack. Two aircraft carriers, USS Enterprise (CV-6) and USS Hornet (CV-8), together with four cruisers, eight destroyers and two fleet oilers, carried sixteen U.S. Army Air Force B-25 Mitchell medium bombers within striking distance of Tokyo in the first offensive action against Japan by the United States. With the land-based bombers secured to Hornet‘s flight deck, her own fighters had been struck below. The air group from Enterprise provided Combat Air Patrol for the task force. The plan was to bring the B-25s within 400 miles (645 kilometers) of Japan, have them take off and carry out the attack, then fly on to airfields in friendly Chinese territory.

A U.S. Army Air Corps B-25B Mitchell medium bomber is launched from USS Hornet (CV-8), 18 April 1942. (U.S. Navy)
Lieutenant Colonel James H. ("Jimmy") Doolittle, U.S. Army Air Corps, flies a North American Aviation B-25B Mitchell medium bomber off the deck of USS Hornet (CV-8), 18 April 1942. (U.S. Navy)
Lieutenant Colonel James H. (“Jimmy”) Doolittle, U.S. Army Air Corps, flies a North American Aviation B-25B Mitchell medium bomber off the deck of USS Hornet (CV-8), 18 April 1942. His was the first bomber to takeoff. (U.S. Navy)

At 0500 hours, the task force was sighted by a Japanese picket boat while still over 700 miles (1,127 kilometers) away from Tokyo. At 0644 another vessel was spotted by the task force. Fearing that surprise had been lost, Admiral Halsey ordered the bombers launched while still 623 miles (1,003 kilometers) from land.

Admiral William H. Halsey watches a North American Aviation B-25B Mitchell medium bomber take off from USS Hornet (CV-8). The airplanes nose wheel has cleared the flight deck while the ship's bow pitches down in heavy seas. (U.S. Navy)
Vice Admiral William H. Halsey, U.S. Navy, watches a North American Aviation B-25B Mitchell medium bomber take off from USS Hornet (CV-8). The airplane’s nose wheel has lifted clear of the flight deck while the ship’s bow pitches down in heavy seas. (U.S. Navy)
Lt. Col. James H. Doolittle, USAAF, aboard USS Hornet, April 1942. (U. S Air Force)
Lt. Col. James H. Doolittle, USAAC, aboard USS Hornet, April 1942. (U. S. Air Force)

The sixteen bombers were successfully launched from Hornet and headed for their assigned targets. The lead airplane, B-25B serial number 40-2344, was flown by Lieutenant Colonel James H. Doolittle, United States Army Air Forces, commanding the strike force. The first bombs were dropped on Tokyo at 1215 local time. Single B-25s each attacked targets in the cities of Nagoya, Osaka and Kobe.

The actual destructive effect of the attack was minimal. It had been hoped that there would be psychological effects on the citizenry, however the arrival of the American bombers coincided with an ongoing air raid drill, and many thought it was all part of the drill. Militarily, however, the attack was a stunning success. Four Japanese fighter groups, needed elsewhere, were pinned down at home, waiting for the next attack.

A B-25 is airborne over the bow of USS Hornet (CV-8). (U.S. Navy)
A B-25 is airborne over the bow of USS Hornet (CV-8). (U.S. Navy)

Not a single B-25 was lost over Japan. One landed in Vladivostok where the crew and airplane were interred by the “neutral” Russians, but they eventually were able to get home. The rest continued on toward China, though without enough fuel to reach their planned destinations. Four B-25s made crash landings, but the crews of the others bailed out into darkness as their planes ran out of gas. Five men were killed. Eight were captured by the Japanese, two of whom were executed by a military court, and another died in prison.

North American Aviation B-25B interred south of Vladivostok
Captain Edward J. York’s North American Aviation B-25B Mitchell, 40-2242, Aircraft 8, interned about 40 miles (25 miles) west of Vladivostok, Primorsky Krai, Union of Soviet Socialist Republics.
1st Lieutenant Robert L. Hite, USAAF, co-pilot of Aircraft 16, Bat Out of Hell, was captured by the Japanese after bailing out over China. he was held as a prisoner of war for 3½ years. He is one of just five living members of the Doolittle Raiders, though he was too ill to attend their 2012 Reunion. (U.S. Air Force)
1st Lieutenant Robert L. Hite, USAAC, co-pilot of Aircraft 16, “Bat Out of Hell,” was captured by the Japanese after bailing out over China, and was held as a prisoner of war for 3½ years. Colonel Hite died Sunday, 29 March 2015 at the age of 95 years. Only one of the Doolittle raiders, Richard Cole, is still living. (U.S. Air Force)

© 2017, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

14 April 1986

General Dynamics F-111F Aardvark with 2000 pound GBU-10 Paveway II laser-guided bombs at RAF Lakenheath, 14 April 1981. (U.S. Air Force)
General Dynamics F-111F Aardvark with 2000 pound GBU-10 Paveway II laser-guided bombs at RAF Lakenheath, 14 April 1981. (U.S. Air Force)

14 April 1986: In response to several acts of international terrorism sponsored by the Libyan regime of Muammar Khadafi, the United States launched Operation El Dorado Canyon. Along with A-6E Intruders, F/A-18 Hornets and A-7 Corsair IIs from the aircraft carriers USS America and USS Coral Sea, 24 General Dynamics F-111F Aardvarks of the 48th Tactical Fighter Wing from RAF Lakenheath, accompanied by EF-111 Ravens for electronic counter measures, and flew 3,500 miles to their targets.

Navy aircraft attacked Benina Airfield and the Benghazi barracks, while the Air force fighter bombers, using GBU-10 Paveway II 2,000-pound laser-guided bombs, attacked the Aziziyah Barracks and the Sadi Bilal terrorist training camp at Tripoli. Because of the length of the flight, the F-111s had to refuel from KC-10 Extender air tankers, four times in each direction. The KC-10s, in turn, refueled in flight from KC-135 Stratotankers.

There were very stringent rules of engagement in place, and for that reason, the majority of the Aardvarks did not release their bombs.

Libya had some of the most sophisticated air defenses in the world. Analysis indicated that only three cities in Russia were more heavily defended. Even so, of the 55 aircraft in the two attack forces, only one F-111 was lost, probably shot down by a surface-to-air missile. Its two man crew were killed.

A number of Libyan aircraft and facilities were destroyed. 37 people were killed and 93 wounded. From the standpoint of destruction caused, the results were minimal. But the effects on Colonel Khadafi were pronounced, and resulted in a significant scaling back of his regime’s terrorist activities. Viewed from that perspective, the mission was a complete success.

General Dynamics F-111F 70-2380, 48th Tactical Fighter Wing, with wings swept for high-speed flight, over a desert landscape. (U.S. Air Force)
General Dynamics F-111F 70-2380, 48th Tactical Fighter Wing, with wings swept for high-speed flight, over a desert landscape. (U.S. Air Force)

© 2015, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

6 April 1955, 18:00:04.1 UTC

Operation Teapot HA fireball, 6 April 1955. (U.S. Air Force)
Operation Teapot HA fireball, 6 April 1955. (U.S. Air Force)

6 April 1955: At 10:00:04.1 a.m. local time (1800 GMT), a Convair B-36H assigned to the 4925th Test Group (Atomic) at Kirtland Air Force Base, New Mexico dropped an atomic weapon from 42,000 feet (12,802 meters) over the Nevada Test Site, Area 1. The bomb was parachute-retarded to slow its fall so that the bomber could escape its blast effects.

The weapon was a test device to investigate its use as an air-to-air anti-aircraft missile warhead. It detonated at 36,620 feet (11,162 meters) with an explosive force of 3.2 kilotons. Because of the altitude of the explosion, there was no significant fallout.

“All test observers (with goggles) agreed that the fireball appeared more intensely bright than in events of similar yield fired at lower altitude.”United States High-Altitude Test Experiences by Herman Hoerlin, Los Alamos Scientific Laboratory, June 1976, at Page 12.

Captain William L. Hickey, USAF, pilot of a Convair B-36 Peacemaker very long-range heavy bomber during Operation Teapot, 1955. Captain Hickey is wearing a David Clark Co. S-2 capstan-type partial-pressure suit and K-1 helmet for protection at high altitude. (U.S. Air Force via Jet Pilot Overseas)
Captain William L. Hickey, USAF, pilot of a Convair B-36 Peacemaker very long-range heavy bomber during Operation Teapot, 1955. Captain Hickey is wearing a David Clark Co. S-2 capstan-type partial-pressure suit and K-1 helmet for protection at high altitude. (U.S. Air Force via Jet Pilot Overseas)
A smoke ring formed following the detonation of the Operation Teapot HA test. Contrails of the test aircraft are visible. (U.S. Air Force)
A smoke ring formed following the detonation of the Operation Teapot HA test. Contrails of the test aircraft are visible. (U.S. Air Force)

The test device was designed at the Los Alamos Scientific Laboratory (LASL) in New Mexico and was similar to the Wasp Prime device, which had been detonated earlier in the Operation Teapot test series. It used a spherical implosion device. The warhead was a 17-inch (43.2 centimeters) diameter sphere weighing approximately 125 pounds (56.7 kilograms). It was placed inside a Mark 5 bomb case which weighed 1,085 pounds (492.2 kilograms).

This was the only bomb dropped by parachute at the Nevada Test Site.

Flight crew of a Convair B-36 Peacemaker, 4925th Test Group (Atomic) during Operation Teapot, 1955. The crewmen are wearing David Clark Co. S-2 capstan-type partial-pressure suits for protection at high altitude. The two white helmets are early K-1 "split shell" 2-piece helmets, while the green helmets are later K-1 1-piece models. (U.S. Air Force via Jet Pilot Overseas)
Flight crew of a Convair B-36 Peacemaker, 4925th Test Group (Atomic) during Operation Teapot, 1955. The crewmen are wearing David Clark Co. S-2 capstan-type partial-pressure suits for protection at high altitude. The two white helmets are early K-1 “split shell” two-piece helmets, while the green helmets are later K-1 one-piece models. (U.S. Air Force via Jet Pilot Overseas)

The Convair B-36H Peacemaker was the definitive version of the ten engine bomber, with 156 B-36H/RB-36H built out of the total production of 383 Peacemakers. It is similar to the previous B-36F variant, though with a second flight engineer’s position, a revised crew compartment, and improved radar controlling the two 20 mm autocannons in the tail turret.

It is 162 feet, 1 inch (49.403 meters) long with a wingspan of 230 feet (70.104 meters) and overall height of 46 feet, 8 inches (14.224 meters). The empty weight is 168,487 pounds (776,424.4 kilograms) and combat weight is 253,900 pounds (115,167.1 kilograms). Maximum takeoff weight is 370,000 pounds (167,829.2 kilograms).

Three flight crewmen don their parachutes before boarding the B-36H Peacemaker for Operation Teapot HA, 5 April 1955. The automobile behind them is a 1955 Chevrolet Bel Air 4-door sedan. (U.S. Air Force)
Three flight crewmen don their parachutes before boarding the B-36H Peacemaker for Operation Teapot HA, 5 April 1955. The automobile behind them is a 1955 Chevrolet Bel Air 4-door sedan. (U.S. Air Force)

The B-36H has ten engines. There are six air-cooled, supercharged 4,362.49 cubic-inch-displacement (71.49 liter) Pratt & Whitney Wasp Major C6 (R-4360-53) four-row, 28-cylinder radial engines placed inside the wings in a pusher configuration. These had a compression ratio of 6.7:1 and required 115/145 aviation gasoline. The R-4360-53 had a Normal Power rating of 2,800 horsepower at 2,600 r.p.m. Its Military Power rating was 3,500 horsepower at 2,800 r.p.m., and 3,800 horsepower at 2,800 r.p.m. with water injection—the same for Takeoff. The engines turned three-bladed Curtiss Electric constant-speed, reversible propellers with a diameter of 19 feet, 0 inches (5.791 meters) through a 0.375:1 gear reduction. The R-4360-53 is 9 feet, 9.00 inches (2.972 meters) long, 4 feet, 7.00 inches (1.397 meters) in diameter, and weighs 4,040 pounds (1,832.5 kilograms).

Four General Electric J47-GE-19 turbojet engines are suspended under the wings in two-engine pods. The J47 is a  single-shaft axial-flow turbojet engine with a 12-stage compressor section, 8 combustion chambers, and single-stage turbine. The J47-GE-19 was modified to run on gasoline and was rated at 5,200 pounds of thrust (23.131 kilonewtons).

The B-36H was the fastest variant of the Peacemaker series, with a cruise speed of 234 miles per hour (377 kilometers per hour) and a maximum speed of 416 miles per hour (670 kilometers per hour) at 36,700 feet (11,186 meters) and 439 miles per hour (709 kilometers per hour) at 31,120 feet (9,485 meters). The service ceiling was 44,000 feet (13,411 meters) and its combat radius was 3,113 miles (5,010 kilometers). The ferry range was 7,691 miles (12,378 kilometers).

The B-36H has six remotely-controlled retractable gun turrets mounting two M24A1 20 mm autocannon, per turret. There is a tail turret, mentioned above, and another 2-gun turret in the nose.

The B-36 was designed during World War II, when nuclear weapons were unknown to the manufacturer. The bomber was built to carry up to 86,000 pounds (39,009 kilograms) of conventional bombs in two bomb bays. It could carry the 43,600 pound (19,777 kilogram) T-12 Cloudmaker, a conventional explosive earth-penetrating bomb, or several Mk.15 thermonuclear bombs. By combining the bomb bays, one Mk.17 25-megaton thermonuclear bomb could be carried.

This Convair RB-36D-5-CF, 49-2686, is similar in appearance to the B-36H used in Operation Teapot HA. (U.S. Air Force)
This Convair RB-36D-5-CF, 49-2686, is similar in appearance to the B-36H used in Operation Teapot HA. (U.S. Air Force)

© 2017, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

25 March 1956

Martin XB-51 46-685, the number one prototype, on takeoff. (U.S. Air Force)
Martin XB-51 46-685, the number one prototype, on takeoff. (Lockheed Martin)

25 March 1956: At approximately 10:50 a.m., the first of two prototype Martin XB-51 three-engine attack bombers, serial number 46-685, crashed on takeoff from Runway 22 at El Paso International Airport (ELP). The pilot, Major James O. Rudolph, United States Air Force, survived the crash although he was  seriously burned. Staff Sergeant Wilbur R. Savage, 28, engineer, was killed. Major Rudolph died of injuries 16 April 1956.

Pieces of wreckage were marked “Gilbert XF-120” which had been painted on the airplane for the filming of the William Holden, Lloyd Nolan movie, “Toward The Unknown.” (Toluca Productions, 1956). The second prototype, 46-686, had previously crashed at Edwards AFB.

A newspaper article from the El Paso Times is quoted below [I have corrected some typographical errors]:

03/26/1956

Bill Feather
El Paso Times

A sleek jet bomber, carrying a full load of fuel, crashed while attempting a take-off at International Airport Sunday morning, killing the flight engineer and seriously injuring the pilot.

The XB-51, the only one of its type in existence, smashed through the fence at the end of the southwest runway and then began to disintegrate, spreading wreckage along a 250-yard trail.

Only the tail section of the three-engine bomber was left intact.

Name of the dead man, a 28-year-old staff sergeant was withheld pending notification of next of kin.

Flying the aircraft was Maj. James O. Rudolph, 36, one of the top test pilots in the Air Force.

He suffered severe burns and was taken Sunday afternoon in an emergency flight to Brooke Army Hospital in San Antonio.

The XB-51, based at Edwards Air Force Base in Muroc, Calif., was being flown to Eglin Air Force Base, Florida, where it was to be used in the filming of a Warner Brothers movie, “Toward the Unknown.”

Identification of the aircraft was confused for a short time after the crash.

A piece of wreckage with the notation “Gilbert XF-120” was found nearby.

HAD REFUELED

Air Force spokesmen explained that the XF designation had been painted on the plane for use in the movie.

The airplane had been refueled at International Airport and started its takeoff at 10:30 a.m.

Witnesses said the plane got about three feet above the ground and suddenly settled. The tail dragged first and then the rest of the airplane settled, running at high speed.

It ripped through a barbed wire fence at the end of the runway, raced across Airport Road and then began to go to pieces.

After crashing, it burned and several explosions threatened firemen, rescuers and spectators who crowded around the flaming aircraft.

First person to the scene of the crash was Eddie C. Wilkerson, 1106 Del Monte Drive, tennis coach at Austin High School.

“I was just turning into the road to the airport when the plane was taking off. I don’t believe it ever got airborne.

“I looked back and saw a big ball of smoke, so I just wheeled my car around.”

Wilkerson said that when he arrived, the major was lying on the ground about 15 feet from the burning wreckage.

“His clothes were burning so I started tearing them off.”

Other witnesses to the crash arrived and helped Wilkerson move the major to a safer place, away from the intense heat of the flaming aircraft.

Capt. John D. Chandler, a doctor at the Biggs Hospital, was at the airport when the crash occurred and he was one of the first persons at the scene. He administered aid to the injured man until an ambulance arrived. Later Capt. Chandler flew to San Antonio with Maj. Rudolph.

A fire truck from International Airport was rushed to the scene almost as soon as the plane stopped its forward motion.

Sunday drivers were attracted to the scene by the tower of smoke and the heavy traffic delayed the arrival of fire trucks from Biggs Air Force Base.

The plane was one of two XB-51s built by Martin Aircraft Co. and was completed in 1953.

The first one crashed at Muroc, Calif., in 1952.

Air Force spokesmen said the aircraft was comparable to the B-47, which was accepted instead of the XB-51 for use in the Air Force.

Its three jet engines one in each wing and on in the fuselage, were capable of driving the craft at tremendous speeds. The aircraft had broken the sound barrier, spokesmen said.

Its sleek lines gave it the appearance of a fighter rather than a medium bomber.

Normally, the airplane carried a crew of three.

Recently it had been used in assisting the Army in missile and anti-aircraft development at Aberdeen Proving Ground, Md.

A board of officers was investigation the crash and two Air Force colonels arrived at Biggs Air Force Base from Muroc Sunday afternoon.

Military police from Ft. Bliss and Air Police patrolled the area about the crash Sunday afternoon, keeping away the curious.

— http://elpasotimes.typepad.com/morgue/2011/03/today-in-1956-plane-crash-kills-engineer-pilot-injured-as-bomber-falls-.html

James Otto Rudolph was born at Marion, Ohio, 8 February 1920, the first of two children of of Frank Otto Rudolph, a German immigrant who was employed as a secretary for the YMCA, and Helen Claire Shafer Rudolph.

Following two years of college, Rudolph enlisted as an Aviation Cadet, U.S. Army Air Corps, at Detroit, Michigan, 17 March 1941. He was 6 feet, 1inch (1.854 meters) tall and weighed 175 pounds (79.4 kilograms). He was commissioned as a Second Lieutenant, Air Reserve, 31 October 1941,and was promoted to First Lieutenant, Army of the United States (Air Corps), 5 August 1942. He was again promoted, to Captain, and again, 15 June 1943. Following the end of World War II, Rudolph was promoted to the rank of Major, 19 September 1946. He remained in the Air Force, but with military needs shrinking, he reverted to the rank of First Lieutenant, with date of rank, 7 December 1944.

James Rudolph married Clara D.    in 194–

Major Rudolph graduated from the U.S. Air Force Experimental Flight Test Pilot School, Class 54-A, 2 July 1954. As a test pilot at Edwards Air Force Base, Rudolph was a project pilot in the FICON program in which Republic RF-84K Thunderflash reconnaissance planes were carried by modified Convair RB-36D bombers.

During his military career, Major Rudolph had been awarded the Air Medal with three oak leaf clusters (four awards).

After the crash on 25 March 1956, Major Rudolph was taken to Brooke Army Hospital, Fort Sam Houston, Texas, suffering from 2nd and 3rd degree burns over 38% of his body. He contracted septicemia and died there, 16 April 1956. He is buried at Arlington National Cemetery.

The first Martin XB-51, 46-585, in flight. (U.S. Air Force)

The Glenn L. Martin Co. XB-51 was a prototype jet-powered attack bomber. It was an unusual design for its time. The airplane had mid-mounted, variable-incidence swept wing, a T-tail and tandem landing gear with a configuration similar to that used on the Boeing B-47 Stratojet (and which had been tested using a Martin B-26 Marauder medium bomber.)

The XB-51 was operated by a pilot in a single-place cockpit with a bubble canopy, and a navigator station inside the fuselage, below and behind the pilot. The prototype was 85 feet, 1 inch (25.933 meters) long with a wingspan of 53 feet, 1 inch (16.180 meters) and overall height of 17 feet, 4 inches (5.283 meters). The airplane had an empty weight of 29,584 pounds (13,419 kilograms) and gross weight of 55,923 pounds (25,366 kilograms).

The wings of the XB-51 were swept to 35° and had 6° anhedral. The wings’ angle of incidence (the relation of the chord to the fuselage longitudinal axis) could be adjusted to increase lift for takeoff and landing. They also were equipped with leading edge slats for improved low speed performance. Instead of ailerons, the XB-51 used spoilers.

Lloyd Nolan (“General Bill Banner”) and William Holden (“Major Lincoln Bond”) with the “Gilbert XF-120” in the 1956 Hollywood movie, “Toward the Unknown.” (Toluca Productions via Turner Classic Movies)

Power was supplied by three General Electric J47-GE-13 turbojet engines, with two located in nacelles outboard of the forward fuselage on 45° pylons, and a third installed in the tail with its intake on top of the fuselage. The J47-GE-13 was an axial-flow turbojet with a 12-stage compressor and single stage turbine. It was rated at 5,200 pounds of thrust (23.13 kilonewtons) at Sea Level. The engine was 12 feet, 0.0 inches (3.658 meters) long, 3 feet, 3.0 inches (0.991 meters) in diameter and weighed 2,525 pounds (1,145 kilograms). A Rocket Assisted Takeoff (RATO) system was also installed.

The XB-51 had a cruise speed of 532 miles per hour (856 kilometers per hour) and a maximum speed of 645 miles per hour (1,038 kilometers per hour) at Sea Level—0.x Mach). The service ceiling was 40,500 feet (12,344 meters) and range was 1,075 miles (1,730 kilometers).

Armament was planned for a maximum bombload of 10,400 pounds (4,717 kilograms) carried internally in a rotary bomb bay, and eight M39 20 mm revolving autocannon mounted in the nose with 1,280 rounds of ammunition.

Martin XB-51 46-685 during engine start and ground run-up. (U.S. Air Force)

© 2017 Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

19 March 1945

Pilot Officer P. Martin's Avro Lancaster B Mk.I Special, PB996, YZ-C, releases the 22,000-pound Grand Slam earth-penetrating bomb over teh railway viaduct at Arnsberg, Germany, 19 March 1945. (Imperial War Museum)
Pilot Officer P. Martin’s Avro Lancaster B Mk.I Special, PB996, YZ-C, releases the 22,000-pound Grand Slam earth-penetrating bomb over the railway viaduct at Arnsberg, Germany, 19 March 1945. © IWM (CH 15735)
The Grand Slam bomb drops away from the No. 617 Squadron Lancaster B Mk.I Special, YZ-C, 19 March 1945. (Imperial War Museum)
The Grand Slam bomb drops away from the No. 617 Squadron Lancaster B Mk.I Special, YZ-C, 19 March 1945. © IWM (CH 15374)

19 March 1945: Modified Avro Lancaster B Mk.I Special heavy bombers of No. 617 Squadron, Royal Air Force, attacked the railway viaduct at Arnsberg, Germany, using the 22,000 pound (9,979 kilogram) Grand Slam earth-penetrating bomb. The bomb had been first used just days before, 14 March, against another railway viaduct.

The Grand Slam bomb dropped by Flying Officer Martin's Avro Lancaster exploeds underneath the railway viaduct at Arnsberg, Germany. (Imperial War Museum)
The Grand Slam bomb dropped by Flying Officer Martin’s Avro Lancaster explodes underneath the railway viaduct at Arnsberg, Germany. Bomb craters from previous unsuccessful attacks are visible in this RAF photograph. © IWM (CH 15378)

The Grand Slam was the largest and heaviest aerial bomb used during World War II. It was designed by aircraft engineer Barnes Neville Wallis, and was scaled up from his earlier, smaller “Tallboy.” (Wallis also designed the “Upkeep” Special Mine used to attack hydroelectric dams in the Ruhr Valley in 1943.)

Wallis’ idea was that a very heavy, supersonic bomb could penetrate deep into the earth and detonate, causing an “earthquake” which could destroy nearby heavily protected targets.

The Grand Slam bomb was 26 feet, 6 inches (8.077 meters) long and had a maximum diameter of 3 feet, 6 inches (1.067 meters). When fully loaded with the explosive material, Torpex, the bomb weighed 22,000 pounds (9,979 kilograms). The bomb case was cast of steel at the Clyde Alloy and Steel Company, Galsgow, Scotland, then, after several days of cooling, machined to its precise shape. The casing made up approximately 60% of the bomb’s total weight.

A "Bomb, Medium Capacity, 22,000 Pounds, lifted by a crane at a Royal Air Force bomb dump. (Imperial War Museum)
A “Bomb, Medium Capacity, 22,000 Pounds”—the Grand Slam—lifted by a crane at a Royal Air Force bomb dump. © IWM (CH 15369)

The bomb case was filled with molten Torpex. Torpex was an explosive designed for torpedo warheads and depth charges. It was made up of approximately equal quantities of two other explosives, Research Department Formula X (RDX), 42%, and trinitrotoluol (TNT), 40%, mixed with 18% powdered aluminum and wax. The resulting combination was approximately 1.4 times more powerful than TNT alone. About one month was required for the explosive to cool after being poured into the bomb case.

Because of its size and weight, the only Allied bomber capable of carrying the Grand Slam was a specially modified Avro Lancaster B.I Special, flown by No. 617 Squadron, Royal Air Force, “The Dambusters.”

Wallis intended for the Grand Slam to be dropped from very high altitudes so that during its fall, it would go supersonic. The bomb had large fins that caused it to rotate for stability. However, the bombers could not carry it to the planned release altitude, and it was typically dropped from approximately 9,000 feet (2,743 meters). Its very sleek design did allow it to come close to the speed of sound, however, and its stability made it a very accurate weapon. The bomb was capable of penetrating 20-foot-thick (6 meters) reinforced concrete roofs of submarine bases.

A Grand Slam bomb penetrated this reinforced concrete submarine pen. man at the top of the photograph gives scale. (Imperial War Museum)
A Grand Slam bomb penetrated the 7 meter (23 feet) thick roof this reinforced concrete submarine pen. The man at the top of the photograph gives scale. (Imperial War Museum)

Barnes Neville Wallis, Esq., M. Inst. C.E., F.R.Ae.S., Assistant Chief Designer Vickers-Armstrongs Ltd., was appointed Commander of the Most Excellent Order of the British Empire (Civil Division), by His Majesty, King George VI, 2 June 1943.

Sir Barnes Neville Wallis C.B.E., was knighted by Her Majesty, Queen Elizabeth II, 13 December 1968.

© 2017, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather