The Bomb, Medium Capacity, (Grand Slam) was a
earthquake bomb
The earthquake bomb, or seismic bomb, was a concept that was invented by the British aeronautical engineer Barnes Wallis early in World War II and subsequently developed and used during the war against strategic targets in Europe. A seismic bomb ...
used by
RAF Bomber Command
RAF Bomber Command controlled the Royal Air Force's bomber forces from 1936 to 1968. Along with the United States Army Air Forces, it played the central role in the strategic bombing of Germany in World War II. From 1942 onward, the British bo ...
against German targets towards the end of the
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. The bomb was originally called Tallboy Large until the term Tallboy got into the press and the code name was replaced by "Grand Slam". The bomb was similar to a large version of the
Tallboy bomb
Tallboy or Bomb, Medium Capacity, 12,000 lb was an earthquake bomb developed by the British aeronautical engineer Barnes Wallis and used by the Royal Air Force (RAF) during the Second World War."Medium capacity" refers to the ratio of bomb ...
but a new design and closer to the size that its inventor,
Barnes Wallis
Sir Barnes Neville Wallis (26 September 1887 – 30 October 1979) was an English engineer and inventor. He is best known for inventing the bouncing bomb used by the Royal Air Force in Operation Chastise (the "Dambusters" raid) to attack ...
, had envisaged when he developed the idea of an earthquake bomb.
Medium Capacity (M.C.) bombs were designed to remedy the shortcomings of General Purpose (G.P.) bombs, with a greater blast and casings which were robust enough to confer a considerable capacity to penetrate, especially the Tallboy and Grand Slam. The Grand Slam case was made of a chrome-molybdenum
alloy steel
Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties. Alloy steels are broken down into two groups: low alloy steels and high alloy steels. The differe ...
and had a charge-to-weight ratio of over 43 per cent.
Conventional
Avro Lancaster
The Avro Lancaster is a British Second World War heavy bomber. It was designed and manufactured by Avro as a contemporary of the Handley Page Halifax, both bombers having been developed to the same specification, as well as the Short Stirlin ...
bombers could not carry the bomb and 32 Lancaster B.Mk 1 (Special)s with more powerful engines, a stronger undercarriage, without bomb bay doors and minus many items to save weight, were built. When airborne with the Grand Slam a Special could barely manoeuvre and pilots were advised to refrain from minor adjustments of the flying controls, allowing the aircraft to wallow. A Lancaster which returned with its bomb was not permitted to land at RAF Woodhall Spa, the
617 Squadron
Number 617 Squadron is a Royal Air Force aircraft squadron, originally based at RAF Scampton in Lincolnshire and currently based at RAF Marham in Norfolk. It is commonly known as "''The Dambusters''", for its actions during Operation Chastis ...
base, but had to use the longer runway at
RAF Carnaby
Royal Air Force Carnaby or more simply RAF Carnaby is a former Royal Air Force emergency landing strip that offered crippled bombers a safe place to land near the English coast during the Second World War. It was situated south-west of Bridling ...
.
From 14 March to 19 April 1945, 42 Grand Slams were dropped on Germany. When landing on reinforced concrete, the bombs tended to break up when they hit or explode prematurely. The bombs had been designed to land in soft ground, penetrate deeply and then explode, creating a , causing the structure above to subside. Grand Slams and Tallboys were capable of causing damage that smaller bombs could not, accelerating the collapse of German resistance and avoiding mass civilian casualties. Grand Slams were the most effective bombs used by the Allies until the advent of nuclear weapons later that year. After the war, the
Royal Air Force
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and ...
and
United States Army Air Forces
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...
used Grand Slams and other bombs for research.
Background
Medium Capacity bombs
Medium Capacity (M.C.) bombs were designed to address the shortcomings of General Purpose (G.P.) bombs, which had a charge-to-weight ratio of about 27 per cent (contemporary German bombs had a ratio of fifty per cent). M.C. bombs were to have a charge-to-weight ratio of at least forty per cent and use explosives of greater power, although shortages often led to inferior explosive types being used. High Capacity (H.C.) bombs had a charge-to-weight ratio of up to 75 per cent. M.C. bombs had greater blast effect than G.P. bombs but had casings which were robust enough to confer a considerable capacity to penetrate.
Grand Slam
![Grand Slam bombs awaiting delivery (19456323542)](https://upload.wikimedia.org/wikipedia/commons/0/09/Grand_Slam_bombs_awaiting_delivery_%2819456323542%29.jpg)
On 18 July 1943, after the
Dams raid
Operation Chastise or commonly known as the Dambusters Raid was an attack on German dams carried out on the night of 16/17 May 1943 by 617 Squadron RAF Bomber Command, later called the Dam Busters, using special "bouncing bombs" developed by ...
, the Controller of Research and Development at the
Ministry of Aircraft Production
Ministry may refer to:
Government
* Ministry (collective executive), the complete body of government ministers under the leadership of a prime minister
* Ministry (government department), a department of a government
Religion
* Christian ...
(MAP) received a requirement for twelve Tallboy Small [] bombs, 60 unfilled Tallboy Medium (Tallboy) bombs and 100 Tallboy Large. Lack of capacity led to work the Tallboy Large being stopped on 30 September. Interest in the Tallboy Large, renamed Grand Slam on 22 November 1944, after the term Tallboy appeared in the press, increased after better understanding of the effect of the Tallboy was gained by the inspection of targets in Europe. The Tallboy was discovered to be too small to destroy concrete buildings with direct hits; only near misses which opened a under the foundations were found to be effective. In September 1944 the German
V-2 rocket
The V-2 (german: Vergeltungswaffe 2, lit=Retaliation Weapon 2), with the technical name ''Aggregat 4'' (A-4), was the world’s first long-range guided ballistic missile. The missile, powered by a liquid-propellant rocket engine, was developed ...
bombardment of London began, which had been expected by the British since
Operation Hydra, the attack on the
Peenemünde research centre, on the night of 17/18 August 1943 and Grand Slams were considered as a weapon to be used on V-2 launch sites.
Doubts remained at the
Air Ministry
The Air Ministry was a department of the Government of the United Kingdom with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964. It was under the political authority of the Secretary of State ...
; an officer in the planning department was sceptical, even with the discovery of the limits of the Tallboy bomb, about what the Grand Slam could be used on and whether when ready in February–March 1945, there would be anything left to bomb. Aircraft adapted to carry the Grand Slam could not carry any other load. Air Commodore
Christopher Bilney replied that the Tallboy Large would be more useful than the
Upkeep mine used in the Dams raid. At the
Bomber Command
Bomber Command is an organisational military unit, generally subordinate to the air force of a country. The best known were in Britain and the United States. A Bomber Command is generally used for strategic bombing (although at times, e.g. during t ...
headquarters in
High Wycombe
High Wycombe, often referred to as Wycombe ( ), is a market town in Buckinghamshire, England. Lying in the valley of the River Wye surrounded by the Chiltern Hills, it is west-northwest of Charing Cross in London, south-southeast of Ayl ...
, there was a debate about how many Tallboy Large's to order, which ranged from 25 a month to 75. The head of Bomber Command, Air Marshal Sir
Arthur Harris, thought that the new bomb might be useful against U-boat pens and the bigger targets of
Operation Crossbow
''Crossbow'' was the code name in World War II for Anglo-American operations against the German V-weapons, long range reprisal weapons (V-weapons) programme.
The main V-weapons were the V-1 flying bomb and V-2 rocket – these were launched aga ...
(anti-
V-weapons
V-weapons, known in original German as (, German: "retaliatory weapons", "reprisal weapons"), were a particular set of long-range artillery weapons designed for strategic bombing during World War II, particularly strategic bombing and/or aer ...
attacks) but put the burden on the Air Ministry to decide how many to manufacture. In September the decision to make the new bombs was made and 600 were ordered in October; 200 from British sources and 400 from the US. The British order was cancelled on 4 October, leaving only US production, but RAF representatives in the US were able to persuade the Americans to build fifty bomb casings by the end of the year, to be filled in Britain. Four Lancaster bombers for trials were ordered then this was cut to one aircraft. During the
Battle of the Bulge
The Battle of the Bulge, also known as the Ardennes Offensive, was the last major German offensive (military), offensive military campaign, campaign on the Western Front (World War II), Western Front during World War II. The battle lasted fr ...
(16 December 1944 – 25 January 1945) any complacency about an imminent end to the war was confounded; the Grand Slam production order was revised again for 25 from British sources and 200 from the US.
![Bombas terremoto](https://upload.wikimedia.org/wikipedia/commons/8/8c/Bombas_terremoto.svg)
An expanded version of the Tallboy design was not feasible and the
English Steel Corporation
The English Steel Corporation Ltd was a United Kingdom steel producer. The company was jointly owned by Cammell Laird and Vickers and was formed to bring together their basic steel making interests, principally in the Sheffield area but also incl ...
of
Sheffield
Sheffield is a city status in the United Kingdom, city in South Yorkshire, England, whose name derives from the River Sheaf which runs through it. The city serves as the administrative centre of the City of Sheffield. It is Historic counties o ...
began work on "large boilers" in late 1944. Experiments with the composition of the bomb casing to find one that could withstand the shock of impact, a
steel alloy
Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties. Alloy steels are broken down into two groups: low alloy steels and high alloy steels. The differe ...
of
chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal.
Chromium metal is valued for its high corrosion resistance and hardne ...
-
molybdenum
Molybdenum is a chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6. The name is from Neo-Latin ''molybdaenum'', which is based on Ancient Greek ', meaning lead, since its ores were confused with lea ...
. A concrete core, accurate to 1/10,000th of an inch was made, then a sand-covered outer mould was created, into which the molten metal was poured. The core was chipped out after the metal had cooled but hot places on the casing could result in structural flaws, breaking the bomb casing when it hit, with no guarantee of the detonation of its contents. The US casings were made by
electric resistance welding
Electric resistance welding (ERW) is a welding process where metal parts in contact are permanently joined by heating them with an electric current, melting the metal at the joint. Electric resistance welding is widely used, for example, in manufa ...
but both types had to pass stress tests to weed out inadequate examples. The British-made casings were sent on specially-built road trailers, the nose on one and the tail on another, to be machined.
The nose sections were filled by upending them to pour in of
Torpex
Torpex is a secondary explosive, 50% more powerful than TNT by mass. Torpex comprises 42% RDX, 40% TNT and 18% powdered aluminium. It was used in the Second World War from late 1942, at which time some used the names Torpex and RDX interchangeab ...
explosive a bucketful at a time. Once the tail section was connected, the Grand Slam was long, at its widest diameter and weighed . As with the Tallboy, the fins of the Grand Slam were angled and generated a
stabilising spin and the Grand Slam had a charge-to-weight ratio of 43 per cent. Four fuzes were provided, one specially made for the Grand Slam with an 11-second delay, the No. 53 with a thirty-minute delay, a No. 53A with an hour's delay and a No. 37 which had a delay of 6–144 hours. The first bomb arrived at Woodhall Spa on 20 January and fifteen were expected by the beginning of February.
Lancaster B.Mk 1 (Special)
The ten remaining Dambuster Lancasters were sent for storage at the end of 1944 and
617 Squadron
Number 617 Squadron is a Royal Air Force aircraft squadron, originally based at RAF Scampton in Lincolnshire and currently based at RAF Marham in Norfolk. It is commonly known as "''The Dambusters''", for its actions during Operation Chastis ...
was increased from two fights to three, at the expense of
51 Squadron, a
Halifax squadron of
4 Group, which lost a flight. To carry the Grand Slam, specially modified Lancasters were necessary but these would have to be subtracted from the production of conventional Lancasters, at a time when several 5 Group squadrons were converting to Lancaster from Halifaxes. The weight of the Grand Slam meant that only new aircraft would be able to carry it, rather than converting existing and worn aircraft and 32 B.Mk 1 (Special)s were ordered from Avro. There was little agreement on what equipment the specials should carry and Avro backslid on production to get the new
Avro Lincoln
The Avro Type 694 Lincoln is a British four-engined heavy bomber, which first flew on 9 June 1944. Developed from the Avro Lancaster, the first Lincoln variants were initially known as the Lancaster IV and V; these were renamed Lincoln I and ...
, a Lancaster derivative, on schedule. Work began on the specials at the end of January 1945 and two had been built by 13 February, twelve were due within ten days, 24 by month's end and the remainder in March.
PB995 was sent to the
Aeroplane and Armament Experimental Establishment
The Aeroplane and Armament Experimental Establishment (A&AEE) was a research facility for British military aviation from 1918 to 1992. Established at Martlesham Heath, Suffolk, the unit moved in 1939 to Boscombe Down, Wiltshire, where its wo ...
(A&AEE) with PB592/G, a conventional B.Mk 1 built in 1944, which was to be modified to be a B.MK 1 (Special). Some equipment did not need to be fitted but other items were removed, which began a period of removals and reinstatements. A conference on 25 February was necessary to sort out the confusion. The front and mid-upper turrets were to go, along with the H2S, its fairing and the TR1196 R/T set, electric lights, flare chutes, flame dampers, some of the fuel tanks, the rear turret armour, three fire axes, a toolkit and the crew ladder. The commander of 5 Group, Air Vice-Marshal
Ralph Cochrane
Air Chief Marshal Sir Ralph Alexander Cochrane, (24 February 1895 – 17 December 1977) was a British aviator and Royal Air Force officer, perhaps best known for his role in Operation Chastise, the famous "Dambusters" raid.
Early RAF career
Ral ...
ordered that the
Identification friend or foe
Identification, friend or foe (IFF) is an identification system designed for command and control. It uses a transponder that listens for an ''interrogation'' signal and then sends a ''response'' that identifies the broadcaster. IFF systems usual ...
(IFF) be got rid of in favour of the VHF Bomber Fixer. Despite bombing by day, navigation equipment was needed because of the north-west European climate;
GEE and
LORAN
LORAN, short for long range navigation, was a hyperbolic radio navigation system developed in the United States during World War II. It was similar to the UK's Gee system but operated at lower frequencies in order to provide an improved range u ...
were to be carried along with high-altitude and low altitude radio altimeters. The recognition lights and some of the usual VHF equipment were to stay along with the rear guns and 6,000 rounds of ammunition. The bomb doors had to go as even the widened Tallboy bomb doors would not fit a Grand Slam and as the mid-upper gunner and wireless operator were redundant, the crew was cut to five men.
While carrying a Grand Slam, a Lancaster would be incapable of taking evasive action and
Fishpond tail-warning radar went with the H2S set. As
Messerschmitt Me 262
The Messerschmitt Me 262, nicknamed ''Schwalbe'' (German: "Swallow") in fighter versions, or ''Sturmvogel'' (German: "Storm Bird") in fighter-bomber versions, is a fighter aircraft and fighter-bomber that was designed and produced by the Germa ...
jet fighters were operating in northern Germany, an
Automatic Gun-Laying Turret
The Automatic Gun-Laying Turret (AGLT), also known as the Frazer-Nash FN121, was a radar-directed, rear gun turret fitted to some British bombers from 1944. AGLT incorporated both a low-power tail warning radar and fire-control system, which cou ...
(AGLT; also Village Inn or Z Equipment) was considered. The AGLT rear turret had been under test by the Bomber development Unit and two Main Force squadrons of
1 Group, which found that they restricted the view of the rear-gunner; the radar gun laying device was also unable to discriminate between German fighters and friendly bombers and bombers with the turret only flew when not in the company of other Allied aircraft. The aircraft of several bomber groups had been fitted with AGLT transmitters and worked best as an early-warning device and the B.Mk.1 (Special)s were fitted with AGLT in the nose. With a fuel load of the Special would weigh and the first was delivered to
RAF Woodhall Spa
Royal Air Force Woodhall Spa or more simply RAF Woodhall Spa is a former Royal Air Force station located north of Coningsby, Lincolnshire and southeast of Lincoln, Lincolnshire, England.
History
Constructed on farmland south of Woodhall S ...
, the base of 617 Squadron in
Lincolnshire
Lincolnshire (abbreviated Lincs.) is a county in the East Midlands of England, with a long coastline on the North Sea to the east. It borders Norfolk to the south-east, Cambridgeshire to the south, Rutland to the south-west, Leicestershire ...
, on 25 February. There were still arguments about what the Specials would carry, when it was found that Avro had failed to install GEE sets. It was agreed to remove the front turret and its accoutrements; heating was needed for the rear guns and the
Stabilised Automatic Bomb Sight had Tallboy dropping equipment but no capacity to drop practice bombs which needed to be incorporated. The
TR1154 W/T was to be replaced by VHF R/T.
Prelude
B.Mk1 (Special) in flight
In March Lancaster wheels and tyres were replaced by those of the heavier Avro Lincoln and the maximum weight of the Special was set at with a maximum landing weight of excepting emergencies. The commander of 617 Squadron,
John "Johnny" Fauquier, ordered that if returning with a bomb, the Special would divert from Woodhall Spa and use the longer runway at
RAF Carnaby
Royal Air Force Carnaby or more simply RAF Carnaby is a former Royal Air Force emergency landing strip that offered crippled bombers a safe place to land near the English coast during the Second World War. It was situated south-west of Bridling ...
near the coast at
Bridlington
Bridlington is a coastal town and a civil parish on the Holderness Coast of the North Sea in the East Riding of Yorkshire, England. It is about north of Hull and east of York. The Gypsey Race enters the North Sea at its harbour. The 2011 Cen ...
in
East Yorkshire
The East Riding of Yorkshire, or simply East Riding or East Yorkshire, is a ceremonial county and unitary authority area in the Yorkshire and the Humber region of England. It borders North Yorkshire to the north and west, South Yorkshire to th ...
. The centre of gravity when loaded with a Tallboy or Grand Slam was within the aircraft design limits, provided the rear turret was retained.
Merlin 24 engines
at 3,000 rpm, at 3,000 rpm, + boost at were to equip the Special, fitted with paddle-bladed propellers. Particular attention was to be paid to the skin of the wings and rear fuselage when checking the airframe and the Special would take off only from smooth runways and always with experienced pilots. Fuel was to be used from inboard tanks to outboard ones to relieve the stresses on the wings.
The Specials were to have day bomber camouflage, the black underside being painted in ''Sky'' a pale green shade with the upper surfaces keeping the usual dark green and dark earth. To discriminate between Tallboy and Grand Slam Lancasters, the Tallboy aircraft kept the code letters KC and the Specials were coded YZ.
Grand Slam handling
A Ramsome Rapier crane at the A&AEE could lift the Grand Slam when on a concrete base and the Type H trolley was acceptable when limited to with its tyres at 80
PSI
Psi, PSI or Ψ may refer to:
Alphabetic letters
* Psi (Greek) (Ψ, ψ), the 23rd letter of the Greek alphabet
* Psi (Cyrillic) (Ѱ, ѱ), letter of the early Cyrillic alphabet, adopted from Greek
Arts and entertainment
* "Psi" as an abbreviatio ...
. The bomb cradle on the trolley was tilted up at the front to protect the bomb bay roof from damage by the tailfins of the bomb. The bomb was raised into the bomb bay by a crew of six men, who took 35 minutes. Templates were manufactured to help align the bomb in the bay, the front one proving unnecessary and being dispensed with; the rear template was hung from the bomb bay roof. The inside of the Special bomb bay was faired with quick-release panels from the bomb door hinges to the underneath of the fuselage floor to protect pipe-work.
The top of the bomb bay had metal plates installed, the forward bulkhead was faired to the contour of the nose of the Grand Slam and another fairing was fitted to the rearward bulkhead to smooth the airflow as it exited the bay. The usual bomb bay switches were replaced by a master switch; a release cable and lever were fitted to the left hand side of the cockpit for emergencies. The bomb was connected to the bay with a sprung dowel sticking out of the bomb bay roof and a Vickers release unit with metal links, which could be adjusted from within the aeroplane, wrapped around the bomb and released electrically or manually. Fuzing devices in the bomb bay roof worked for the Tallboy as well as the Grand Slam. The new bomb had a two-piece metal skirt between the bomb proper and the tail unit, whose front edge jutted out from the casing of the bomb. As the bomb fell, the slipstream could detach the tail unit of the bomb and the A&AEE advised that it be redesigned.
The bomb dump at Woodhall Spa had been limited to forty Tallboys but room was made to accommodate ten Grand Slams by removing
ordnance
Ordnance may refer to:
Military and defense
*Materiel in military logistics, including weapons, ammunition, vehicles, and maintenance tools and equipment.
**The military branch responsible for supplying and developing these items, e.g., the Unit ...
not in use. In February the A&AEE used PB592/G, a Lancaster B.Mk1, to test loading the Grand Slam using the Type H bomb trolley, which had been designed for the Tallboy and Grand Slam. When the first bomb was moved with an Allen crane, its front wheels rose from the ground as the bomb was lifted and the bomb could not be lowered smoothly, only by unlocking and locking the brake, which dropped the bomb each time. The armourers used a US Bay City crane afterwards with a power-lowering unit added early in 1945.
Grand Slam test
The A&AEE at
RAF Boscombe Down
MoD Boscombe Down ' is the home of a military aircraft testing site, on the southeastern outskirts of the town of Amesbury, Wiltshire, England. The site is managed by QinetiQ, the private defence company created as part of the breakup of the Def ...
had only one bomb to test, with 617 Squadron standing by with the rest, ready to commence operations. The bombing range at the
Ashley Range in the
New Forest
The New Forest is one of the largest remaining tracts of unenclosed pasture land, heathland and forest in Southern England, covering southwest Hampshire and southeast Wiltshire. It was proclaimed a royal forest by William the Conqueror, featu ...
had a concrete target about , to be bombed preferably from the optimum height of . PB955 was loaded with the Grand Slam to be flown by Group Captain H. A. (Bruin) Purvis; bad weather led to two failed attempts to bomb due to mist obscuring the target. On the third attempt, PB592/G, flown by Squadron Leader Headley (Hazel) Hazelden, managed to drop the bomb on 13 March. The aim of the crew was accurate for distance and observers saw the black and white painted bomb rotate as it fell, about off line to starboard. After release, the Grand Slam accelerated to , near supersonic, penetrating deep underground before detonating. The bomb exploded and left a crater in diameter and deep; 617 Squadron was phoned from a nearby pub and told of the success; formal permission to use the bomb was given on 22 March and operations began the same day.
Grand Slam operations, 1945
Bielefeld, 14 March
By mid-March 1945, over had been dropped on the
Bielefeld viaduct
Bielefeld () is a city in the Ostwestfalen-Lippe Region in the north-east of North Rhine-Westphalia, Germany. With a population of 341,755, it is also the most populous city in the administrative region (''Regierungsbezirk'') of Detmold and the ...
in 54 attacks and damage from 17 hits in one raid was repaired in 24 hours. After an abortive attempt against viaducts at Arnsberg and Bielefeld on 9 March the bombers returned on 13 March, when 9 Squadron and 617 Squadron sent 19 Lancasters each against the same targets, two of the 617 Squadron aircraft carrying Grand Slams, escorted by 75 Mustang Mk IIIs from 11 Group. The attack at Arnsberg by 9 Squadron was called off after two aircraft bombed and 617 Squadron turned back from Bielefeld after 129 Squadron (Mustang Mk IIIs) reported unbroken cloud all the way to the target. On 14 March, fifteen Lancasters of 617 Squadron, carrying 14 Tallboys and a Grand Slam, all fuzed for 11 seconds' delay, tried again as fifteen 9 Squadron Lancasters made another attempt against the railway viaduct at Arnsberg. The weather was clear to the targets with some cloud around Bielefeld and a haze over both targets. Escorts from 11 Group consisted of 74 Mustang Mk IIIs and
8 (Pathfinder Force) Group provided four
Oboe
The oboe ( ) is a type of double reed woodwind instrument. Oboes are usually made of wood, but may also be made of synthetic materials, such as plastic, resin, or hybrid composites. The most common oboe plays in the treble or soprano range.
A ...
Mosquitos
Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning "gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "litt ...
each from 105 and 109 squadrons to mark the targets. A Mosquito of
627 Squadron was present to film the attack.
The Lancasters of 617 Squadron flew around Bremen then found that there was cloud on the north side of Bielefeld forcing PD112 ''S'' with the Grand Slam to attack from the south after resetting the SABS, followed by the photographic Mosquito. One of the 105 Squadron Oboe Mosquitoes dropped four Target Indicator bombs which landed about to the south-south-west of the target. At and from , a far from ideal height, the Grand Slam fell from PD112 ''S'', which jumped higher at the loss of weight. After 35 seconds, the bomb hit the ground about short and exploded the site erupting as the Tallboys came down. The pilot of the photographic aircraft, which recorded the attack from shouted "You've done it!". The effect of the Grand Slam could not be distinguished from that of the eleven Tallboys but photographic reconnaissance by a Spitfire from 542 Squadron, following the bombers, then a Mosquito from 540 squadron later on, showed that of the north viaduct and of the south viaduct had been demolished, depositing about of rubble into the valley.
Arnsberg, 15 March
On 15 March, in a haze with some cloud over the target, two aircraft of 617 Squadron with Grand Slams fuzed for 11 seconds' delay and 14 Lancasters of
9 Squadron, carrying Tallboys, attacked the railway viaduct at
Arnsberg
Arnsberg (; wep, Arensperg) is a town in the Hochsauerland county, in the German state of North Rhine-Westphalia. It is the location of the Regierungsbezirk Arnsberg administration and one of the three local administration offices of the Hochs ...
again. A close fighter escort of 34 Mustang Mk IIIs was provided by 11 Group. A photographic Mosquito, KB433, was laid on by 627 Squadron and another 141 fighters were in the vicinity covering raids by 4, 6 and 8 Groups. The long viaduct, built from brick and stone faced with concrete, crossed the Ruhr in five spans. In poor visibility the crew of the photographic Mosquito saw that "the whole force made one run into sun and one bomb seen to drop". This was the first Grand Slam, dropped from at
The photographic crew reported, "Second run into sun and one or two bombs fell. Individual runs then made. No direct hits seen. Majority of bombs fell to the east....". The second Grand Slam was brought home after several bomb runs because of the haze and the Lancaster, PB996, landed at the emergency bomber landing ground at
RAF Manston
Royal Air Force Manston or more simply RAF Manston is a former Royal Air Force station located in the north-east of Kent, at on the Isle of Thanet from 1916 until 1996. The site was split between a commercial airport Kent International Airpor ...
. Ten Tallboys were also dropped with no effect and no aircraft were lost. On the return journey the port inner propeller of NG384 over-speeded and could not be feathered and then oil leaking out from behind the propeller caught fire and the pilot, Flight-Lieutenant F. A. Jones ordered the crew to abandon the aircraft south of the target. Four of the crew parachuted but then the fire went out and Jones force-landed at Gosselies near Brussels.
Arnsberg, 19 March
![Lancaster 617 Sqn RAF dropping Grand Slam bomb on Arnsberg viaduct 1945](https://upload.wikimedia.org/wikipedia/commons/e/e3/Lancaster_617_Sqn_RAF_dropping_Grand_Slam_bomb_on_Arnsberg_viaduct_1945.jpg)
On 19 March, 19 Lancasters of 617 Squadron, six with Grand Slams and 13 with Tallboys, attacked the viaduct again as 9 Squadron attacked the Vlotho rail bridge, in fairly cloudy weather at high altitude, with thin patches lower down. The bombers were escorted by 88 Mustang IIIs from 11 Group. PD329 ''Y'', a Lancaster without bombs from 463 Squadron carried two cameramen from the
RAF Film Unit
Royal Air Force Film Production Unit (typically abbreviated to the acronym RAFFPU) produced propaganda films depicting RAF personnel and aircraft both on the ground and in aerial action during World War II from 1941 to 1945.
History
The RAFFPU ...
accompanied 617 Squadron. A report from
129 Squadron, part of the escorting Mustang force, called the bomber formation tight but then the bombers flew into cloud at . The squadron flew over the Möhne Dam with its barrage balloons, smoke screen and anti-aircraft fire. The cameramen in PD329 ''Y'' had been briefed to film PB966 ''C'', flown by Flight-Lieutenant P. H. Martin and formated on its starboard side, with a cameraman in the nose turret to film the Grand Slam as it fell away and the other on the floor of the fuselage filming vertically. Closer to the target, PD329 ''Y'' dropped back and flew on the port quarter of PB966 ''C''.
The bomb was not to be dropped from under but Martin, the pilot, could not coax the bomber above . On its five-minute bombing run, Martin had to fly within the tolerances of its SABS bombsight, within 0 of airspeed and +/- of altitude. The cameramen started filming and when the bomb dropped, PB966 ''C'' jumped higher. The bomb began its spin and came down on the western span, which disintegrated, along with the roofs of buildings nearby. All but one Lancaster of the first wave, whose Tallboy hung up, bombed. A second wave bombed fairly accurately but one Grand Slam fell off line due to a SABS fault. Two spans of the bridge, about long and one pier had been destroyed, the track on the west bank had been cut, of one of the embankments had been shoved out of line and the entrance to a tunnel on the east bank had been blocked; no damage had been caused to a
Red Cross
The International Red Cross and Red Crescent Movement is a Humanitarianism, humanitarian movement with approximately 97 million Volunteering, volunteers, members and staff worldwide. It was founded to protect human life and health, to ensure re ...
camp nearby. After the war the casings of a Grand Slam and a Tallboy were found at the site; the Grand Slam was thought to have landed flat on a road and only the explosive at the rear of the casing detonated; the Tallboy hit a wall, broke up and buried itself in the ground without going off.
Arbergen, 21 March
![Grand Slam bomb exploding near Arnsberg viaduct 1945](https://upload.wikimedia.org/wikipedia/commons/2/2c/Grand_Slam_bomb_exploding_near_Arnsberg_viaduct_1945.jpg)
Twenty Lancasters of 617 Squadron, two carrying Grand Slams and the rest Tallboys, flew in good weather with little cloud to
Bremen
Bremen (Low German also: ''Breem'' or ''Bräm''), officially the City Municipality of Bremen (german: Stadtgemeinde Bremen, ), is the capital of the German state Free Hanseatic City of Bremen (''Freie Hansestadt Bremen''), a two-city-state consis ...
to attack the double-tracked railway bridge at Arbergen which crossed the
Weser
The Weser () is a river of Lower Saxony in north-west Germany. It begins at Hannoversch Münden through the confluence of the Werra and Fulda. It passes through the Hanseatic city of Bremen. Its mouth is further north against the ports of Bre ...
near
Nienburg. The bridge was long with three steel girder spans. The railway approached the river from the south-west along an embankment until from the river where it crossed a meadow on a low-lying steel viaduct resting on piers. The bombers were escorted by twenty
Mustang Mk IIIs (P-51Cs) of
306 (Polish) Squadron and
309 (Polish) Squadron. Another five fighter squadrons were provided to escort a day raid by 1 and 8 Groups on an oil refinery at Bremen; other Main Force aircraft attacked targets in
Münster
Münster (; nds, Mönster) is an independent city (''Kreisfreie Stadt'') in North Rhine-Westphalia, Germany. It is in the northern part of the state and is considered to be the cultural centre of the Westphalia region. It is also a state distr ...
and
Rheine
Rheine () is a city in the district of Steinfurt in Westphalia, Germany. It is the largest city in the district and the location of Rheine Air Base.
Geography
Rheine is on the river Ems, approx. north of Münster, approx. west of Osnabrück a ...
.
The first Grand Slam was dropped from , landing short and the second fell off target to the north, due to flak (anti-aircraft fire) and aiming problems. The Tallboys hit the middle of the bridge and the ends were blown off their piers; the pier to the east collapsed onto the ground and the western pier was twisted and sagged to the ground at one place; part of the railway track, above the embankment and the first pier on the west side, was wrecked. One Lancaster was shot down near Okel and left a crater deep; five Lancasters were damaged by flak and an attack by a Me 262 jet fighter.
Nienburg, 22 March
Twenty Lancasters of 617 Squadron, six carrying Grand Slams fuzed for 25–30 seconds' delay and 14 with Tallboys with 25–35 seconds' or one-hour delay fuzes, attacked the railway bridge at Nienburg, between Bremen and
Hanover
Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German state of Lower Saxony. Its 535,932 (2021) inhabitants make it the 13th-largest city in Germany as well as the fourth-largest city in Northern Germany ...
, in atmospheric conditions ideal for bombing. A railway bridge at Bremen was attacked at the same time by 9 Squadron with Tallboys. The bombers were escorted by 114 Mustang Mk IIIs and 69 Spitfire Mk IXs from 11 Group squadrons. The Lancasters of 617 Squadron bombed within one minute, dropping five Grand Slams and twelve Tallboys. One Lancaster crew claimed a near miss with a Grand Slam and another crew claimed a hit.
It had been planned that the fourth and eight rows of Lancasters would not bomb on the first pass and Flight Lieutenant L. S. Goodman reported that on the second bomb run the bridge was under water, the spans having been broken of blown off their piers. A third Lancaster crew found that their bomb would not drop despite two attempts and the bridge collapsed before the third try, leaving the crew to take it home. A fourth Grand Slam was reported to have hit the east end of the structure. Reconnaissance photographs showed that the bridge had been destroyed.
Bremen, 23 March
Another railway Bridge near Bremen was attacked later in the day by twenty 617 Squadron Lancasters, six carrying Grand Slams and 14 with Tallboys. The bridge at Bad Oeynhausen was attacked by 9 Squadron. The weather was clear and ideal for bombing but was also good for the Bremen anti-aircraft defences. The bombers were escorted by 41 Mustang Mk IIIs from 11 Group with seven more squadrons in the vicinity. A total of 128 Lancasters took part in the bombing from 1 Group and 5 Group, most accompanying 617 Squadron on the attack on the bridge at Bremen. The Germans started to generate a smoke screen but were too late; two hits were observed before the smoke screen and wreckage blocked the view. The pitch control on one of Lancaster PB996's engines made the aircraft lose speed and its bomb was dropped on a jettison area; the pilot of PD112 decided to bomb despite the bomb-aimers clear vision panel being smashed by flak .
Three hits were claimed and one Tallboy hung up when the bomb aimer tried to drop it then fell off 15 seconds later, overshooting the bridge. Later analysis found that a Tallboy had landed on the bank at the south end of the bridge about from the abutment and the shock of the explosion shifted it, making the span fall into the river. A Tallboy hit the north end of the bridge, the damage being swiftly repaired; another to the south which was filled in and new track laid. Eventually the Germans demolished the bridge to create an obstacle to the Allied ground advance. Lancaster NG489 was hit by flak and the crew jettisoned the Grand Slam to regain control. Several other Lancasters were hit by anti-aircraft fire and four others were attacked by Me 262s, fifteen of which were seen on the flight to the target.
Farge, 27 March
![U-Boat Pen Grand Slammed](https://upload.wikimedia.org/wikipedia/commons/1/13/U-Boat_Pen_Grand_Slammed.jpg)
Twenty Lancasters of 617 Squadron, 13 carrying Grand Slams, the remainder carrying Tallboys, attacked the
Valentin submarine pens
The Valentin submarine factory is a protective shelter on the Weser River at the Bremen suburb of , built to protect German U-boats during World War II. The factory was under construction from 1943 to March 1945 using forced labour, but was dama ...
in clear visibility escorted by 90 Mustang Mk IIIs of 11 Group. Since October 1944, building work had been seen at
Farge
Farge () is a small village in the borough Blumenthal of Bremen, Germany. It is located at the river Weser.
The bombing of Bremen in World War II attacked Farge targets, including the oil storage.
The Farge concentration camp is located nearby ...
, a village on the Weser river, north of
Vegesack
Vegesack is a northern district of the city of Bremen.
Geography
''Vegesack'' is located about north from the centre of Bremen-city at the mouth of the river Lesum, beside the river Weser (). Abutting the district of Vegesack to the northwest is ...
and north-west of Bremen. The building had of the structure above ground and below, was long and wide, enclosing of space. The walls and roof were made of reinforced concrete with arched
truss
A truss is an assembly of ''members'' such as beams, connected by ''nodes'', that creates a rigid structure.
In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so that the assembl ...
es on the walls, filled with concrete. The roof was about thick and was being reinforced to a thickness of . Farge was intended for the assembly of type
XXI U-boats. The shipyard at Vegasack and the site of the building, was code named , construction beginning early in 1943. The site was chosen because it was on the convex side of a curve in the river less prone to silting; the river bed was dredged to a depth of to allow submarine sections in on barges and assembled U-boats out.
Production was expected to begin in March 1945, full production to be achieved in August; the schedule had slipped but production was to start within two months. One Lancaster had returned soon after take-off and another turned back over the target with engine-trouble, ditching the Grand Slam in the North Sea. Moderate to heavy flak was encountered by the gaggle of Lancasters but there was no fighter opposition. The bombs were dropped in about a minute and despite 1-hour delay fuzes, three bombs exploded immediately Two of the fourteen hits on the pens were by Grand Slams and one by a Tallboy, the hits landing on the un-thickened part of the roof on the west side. The Grand Slams penetrated into the concrete causing about of the roof to fall in bringing down two moveable cranes. The thickened part of the roof and a periscope-testing tower were also damaged. One bomb damaged power stations, concrete mixing facilities and shelters on the north side. Marines who had been inside the building reported later that there was a huge concussive effect which severely depressed morale. No aircraft were lost.
Hamburg, 9 April
Seventeen Lancasters from 617 Squadron were dispatched to bomb the Finkenwerder
U-boat pens
A submarine pen (''U-Boot-Bunker'' in German) is a type of submarine base that acts as a bunker to protect submarines from air attack.
The term is generally applied to submarine bases constructed during World War II, particularly in Germany and ...
in
Hamburg
(male), (female) en, Hamburger(s),
Hamburgian(s)
, timezone1 = Central (CET)
, utc_offset1 = +1
, timezone1_DST = Central (CEST)
, utc_offset1_DST = +2
, postal ...
, two with Grand Slams and the rest with Tallboys. The pens were inside a -building with a roof thick, reinforced by steel beams and trusses. Forty Lancasters from 5 Group were to bomb oil storage tanks nearby. The weather was clear with some haze, a thin layer of cirrus clouds above the city but the visibility was very good. A fighter escort from 11 Group consisted of 120 Mustang Mk III, 30 Mustang Mk IV, 59 Spitfire Mk IX and 24 Spitfire Mk XVI to counter any attempts by Me 262 jets to intervene. fighters, including jets, attempted to intercept the formation and there was much flak, which damaged six Lancasters before they bombed. Buildings to the north and west were hit and a reconnaissance photograph showed seven hits, four penetrating the roof.
A post-war report recorded six hits by Tallboys, the two Grand Slams and the other Tallboys landing in the water. The six Tallboys had penetrated the roof part way, hit girders and exploded, blowing holes through the ceiling and depositing hundreds of tons of concrete into the pens. There had been 3,000 people inside the pens, fewer than usual, because it was Poets Day, when German workers left at ; 27 people were killed, about sixty were seriously injured and a panic ensued;
U-906 and
U-1192 were damaged. About thirty Me 262s appeared and
467 Squadron RAAF, on the oil tanks raid, accelerated and turned, ending up bumping along behind the 617 Squadron slipstream. The Mustangs jettisoned their drop tanks and 122 Squadron bounced the German jets which raced away. The Polish 306, 309 and 315 squadrons attacked the jets and claimed three Me 262s shot down and three damaged; two Lancasters were shot down.
Heligoland, 19 April
![Helgoland2021OSM](https://upload.wikimedia.org/wikipedia/commons/d/d4/Helgoland2021OSM.png)
The coastal gun-batteries on the islands of
Heligoland
Heligoland (; german: Helgoland, ; Heligolandic Frisian: , , Mooring Frisian: , da, Helgoland) is a small archipelago in the North Sea. A part of the German state of Schleswig-Holstein since 1890, the islands were historically possessions ...
and
Düne
Düne (Danish: ''Dynen'', North Frisian: ''de Halem'') is one of two islands in the German Bight that form the Archipelago of Heligoland, the other being Heligoland proper.
Geography
The small island of Düne is part of the German State of Schle ...
in the
Heligoland Bight
The Heligoland Bight, also known as Helgoland Bight, (german: Helgoländer Bucht) is a bay which forms the southern part of the German Bight, itself a bay of the North Sea, located at the mouth of the Elbe river. The Heligoland Bight extends fro ...
, the south-eastern extremity of the North Sea, were attacked on 19 April. The military installations on the main island comprised a radar installation covering the
Elbe
The Elbe (; cs, Labe ; nds, Ilv or ''Elv''; Upper and dsb, Łobjo) is one of the major rivers of Central Europe. It rises in the Giant Mountains of the northern Czech Republic before traversing much of Bohemia (western half of the Czech Repu ...
and Weser rivers, an airfield and a coastal battery each of and guns. To ensure that Allied ships could enter the Elbe and Weser estuaries, Bomber Command intended to attack the island with bombs but at least forty heavy anti-aircraft guns on the islands had to be silenced. The gun positions had a diameter of about and only hits or near misses would be effective. On 18 April 969 bombers had attacked the anti-aircraft guns but some remained operational. On 19 April, 20 Lancasters of 617 Squadron attacked with six Grand Slams and fourteen Tallboys and 16 Lancasters from 9 Squadron carried Tallboys fuzed for 25 seconds' delay.
A Mosquito from the RAF Film Unit accompanied the raiders and a fighter escort was provided by 11 Group and
12 Group, consisting of 11 Mustang Mk IIIs, 42 Spitfire Mk IXs and 26 Spitfire XVIs. The gun emplacements were at the north and south ends of the island and three aiming points were chosen, two for 9 Squadron and one for 617 Squadron. Thin stratocumulus cloud was encountered from and six of the 9 Squadron bombers were to act as wind finders, the results being broadcast to the rest of the squadron at H-5. As 9 Squadron flew towards the island they were surprised to see 617 Squadron attacking, climbed out of the way and circled while waiting for their fighter escort. The attack by 617 Squadron was made in two waves against hardly any anti-aircraft fire and all bar one aircraft bombed. Photographic evidence showed two hits on aiming point H and several near misses, which added to the damage. Another attack by the Main Force was planned but the war ended before it took place.
Aftermath
Analysis
In 1991, Alan Cooper wrote that during March 1945, 156 day-sorties were flown, 31 with Grand Slams and 40 with Tallboys. An analysis of the bombing accuracy of 617 Squadron and 9 Squadron on Tallboy sorties found that, using different bomb sights and bombing from heights between , 1 per cent of the Tallboys dropped by 617 Squadron were gross errors
efined as missing the aiming point by more than against 10 per cent of the Tallboys dropped by 9 Squadron. Unlike the Tallboy, the Grand Slam was designed to penetrate concrete roofs and was more effective against fortifications than earlier bombs. By the end of the war, 41 Grand Slams had been dropped on operations although in 2004, Stephen Flower wrote of 42 bombs, a figure he repeated in his 2013 publication.
In 2013, Stephen Flower wrote that when dropped on buildings fortified with reinforced concrete the Grand Slam tended to break up on impact or go off too soon. Flower wrote that it was not surprising that the Grand Slam was limited in effect when dropped on concrete, when it was designed to fall on earth and then explode under the foundations of buildings, creating a for the structure to subside into. The Grand Slam and Tallboy bombs did cause damage that conventional bombs were incapable of and had a great disruptive effect on the means of resistance available to the Germans, limiting the development of new weapons with which to continue the war. In 2013, Stephen Flower wrote that the earthquake bombs rarely caused mass civilian casualties and were the most effective bombs used in the war, until the advent of nuclear bombs later in 1945.
Operation Front Line/Project Ruby
![Luftbild Bunker Valentin](https://upload.wikimedia.org/wikipedia/commons/4/40/Luftbild_Bunker_Valentin.jpg)
Beginning in March 1946, Operation Front Line (British title) / Project Ruby (US title), was a plan to investigate the use of penetration bombs against reinforced concrete targets. The U-boat pens near Bremen were chosen, having been abandoned after the attack on 27 March 1945. Since 9 Squadron and 617 Squadron had been transferred to the Far East to join
Tiger Force
Tiger Force was the name of a long-range reconnaissance patrol unit of the 1st Battalion (Airborne), 327th Infantry, 1st Brigade (Separate), 101st Airborne Division, which fought in the Vietnam War from November 1965 to November 1967. The unit ...
, Grand Slams were carried by Lancasters from
15 Squadron, into whose C Flight, the 617 Squadron crews not sent abroad were moved with their B.Mk 1 (Specials) and their SABS bomb sights. The Watten bunker, in the
Pas de Calais
The Strait of Dover or Dover Strait (french: Pas de Calais - ''Strait of Calais''), is the strait at the narrowest part of the English Channel, marking the boundary between the Channel and the North Sea, separating Great Britain from continent ...
, which has been used for Royal Navy
Disney bomb
The Disney bomb, also known as the Disney Swish, officially the 4500 lb Concrete Piercing/Rocket Assisted bomb was a rocket-assisted bunker buster bomb developed during the Second World War by the British Royal Navy to penetrate hardened con ...
tests, was bombed with Grand Slams.
In May 1946, Operation Front Line began with the participation of US
B-29
The Boeing B-29 Superfortress is an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the B-17 Fly ...
bombers. Tallboy and Grand Slams were dropped on the pens and Heligoland; only two hits were achieved from thirteen bombings. The RAF and USAAF reports concluded that none of the bombs were effective against reinforced concrete and suggested more tests in 1947. The tests were resumed after 15 Squadron had finished dropping fifteen bombs on a battleship for the RN. The squadron was down to six Lancasters, four being B.Mk 1 (Special)s, not capable of carrying the bombs being tested. The other two could carry the bomb but 15 Squadron was re-equipping with Avro Lincolns and six of these were to be altered to carry SABS and radar altimeters. Three USAF B-29s participated again to drop the bombs from which was above the ceiling of the SABS.
![Disney Bomb Diagram](https://upload.wikimedia.org/wikipedia/commons/5/5b/Disney_Bomb_Diagram.png)
The B-29s were also to drop the new US Amazon II and Samson bombs, both , in Operation Ruby II, later called the Harker Project. Photographs taken by
542 Squadron, a photographic reconnaissance unit, before the Grand Slam attack during the war were used to stake out the target with red flags and cameras was set up to film the drops. On 4 August the B-29s achieved six bomb hits from and five Amazon II hits out of fifteen from . From 20 September, 15 Squadron Lincolns dropped the bomb and achieved seven hits, some of which broke on the roof. Tests with a obtained three hits out of seven.
Examples
![Grand Slam bomb RAF Museum London](https://upload.wikimedia.org/wikipedia/commons/1/12/Grand_Slam_bomb_RAF_Museum_London.jpg)
Five Grand Slam bombs are preserved and displayed in Britain at the
RAF Museum, London,
Brooklands Museum,
RAF Lossiemouth
Royal Air Force Lossiemouth or more commonly RAF Lossiemouth is a military airfield located on the western edge of the town of Lossiemouth in Moray, north-east Scotland.
Lossiemouth is one of the largest and busiest fast-jet stations in the R ...
,
Dumfries and Galloway Aviation Museum
The Dumfries and Galloway Aviation Museum is a volunteer-operated aviation museum located in and around the World War II-era watch tower (control tower) at the former RAF Dumfries, located two miles north east of the centre of Dumfries, Scotlan ...
and the Battle of Britain Memorial Flight Visitors' Centre at
RAF Coningsby
Royal Air Force Coningsby or RAF Coningsby , is a Royal Air Force (RAF) station located south-west of Horncastle, and north-west of Boston, in the East Lindsey district of Lincolnshire, England. It is a Main Operating Base of the RAF and hom ...
. Casings, without their tails, can be seen at the
Kelham Island Museum
The Kelham Island Museum is an industrial museum on Alma Street, alongside the River Don, in the centre of Sheffield, England. It was opened in 1982.
The site
The island on which it is located is man-made, resulting from the construction of a ...
in Sheffield and
Yorkshire Air Museum
The Yorkshire Air Museum & Allied Air Forces Memorial is an aviation museum in Elvington, York on the site of the former RAF Elvington airfield, a Second World War RAF Bomber Command station. The museum was founded, and first opened to the pu ...
at Elvington. The
T-12 Cloudmaker
The T-12 (also known as Cloudmaker) earthquake bomb was developed by the United States from 1944 to 1948 and deployed until the withdrawal of the Convair B-36 Peacemaker bomber aircraft in 1958. It was one of a small class of bombs designed to ...
is an American-made variant of the Grand Slam and an example is displayed at the
Air Force Armament Museum
The Air Force Armament Museum is a military aviation museum adjacent to Eglin Air Force Base in Valparaiso, Florida, dedicated to the display of Air Force armament. It is supported by the private, non-profit Air Force Armament Museum Foundation.
...
in the United States.
See also
*
Bunker buster
A bunker buster is a type of munition that is designed to penetrate hardened targets or targets buried deep underground, such as military bunkers.
Armor piercing shells
Germany
Röchling shells were bunker-busting artillery shells, developed by ...
*
FAB-9000
FAB-9000 (ФАБ-9000) was a very large conventional high explosive bomb developed early in the Cold War. The bombs were used by the Iraqi Air Force during the Iran-Iraq war, being dropped from Tu-22 Blinder
The Tupolev Tu-22 (NATO reportin ...
*
T-12 Cloudmaker
The T-12 (also known as Cloudmaker) earthquake bomb was developed by the United States from 1944 to 1948 and deployed until the withdrawal of the Convair B-36 Peacemaker bomber aircraft in 1958. It was one of a small class of bombs designed to ...
*
Thermobaric weapon
A thermobaric weapon, also called an aerosol bomb, a vacuum bomb or a fuel air explosive (FAE), is a type of explosive that uses oxygen from the surrounding air to generate a high-temperature explosion. The fuel–air explosive is one of the be ...
Notes
References
Bibliography
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Further reading
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External links
Movietone News (Youtube com) ''Ten Tonner'' (video of a Grand Slam being dropped on the Bielefeld Viaduct)www.sirbarneswallis.comA picture of a Lancaster carrying a Grand SlamMovietone News "Ten Tonner" – video of a Grand Slam being dropped on the Bielefeld Viaduct on youtube.comThe hole left in the roof by a Grand Slam at the Farge U-boat pen
{{DEFAULTSORT:Grand Slam Bomb
World War II aerial bombs of the United Kingdom
Anti-fortification weapons
History of the Royal Air Force during World War II
Barnes Wallis
Weapons and ammunition introduced in 1944