bombs

bombs were used by bombers and fighter-bombers (see fighters and bombers, 2) of all combatant powers, the principal ones being high explosive (HE), incendiary, anti-personnel, armour-piercing, fragmentation, target indicator, and smoke. There was also the US fire bomb, an aircraft fuel tank filled with napalm (petrol thickened with naphthalic and palmitic acids), employed from mid-1943.

Fuzes could detonate bombs on impact or delay the explosion for several seconds—or several hours—but the percentage of duds on both sides was astonishingly high, perhaps as much as 20%. proximity fuzes, which could explode bombs in the air, had by 1944 proved the best method of maximizing their destructiveness. In certain types of attack parachutes were used to delay the impact, or to ensure an aerial detonation. Most of the aerial mines which the Luftwaffe dropped on British cities were delivered this way, as were the atomic bombs which destroyed Hiroshima and Nagasaki.

The principal German HE bombs were the SC (thin-cased general purpose bomb), SD (thick-cased semi-armoured-piercing fragmentation bomb), and the PC (armour-piercing bomb). Eight out of ten bombs dropped on the UK were SC bombs weighing between 50 kg. and 2,000 kg. (110–4,410 lb.), the 1,000 kg. (2,205 lb.) bomb being known as the ‘Hermann’ because its bulbous casing was reminiscent of Göring's girth. The larger 2,500 kg. (5,510 lb.) bomb, nicknamed ‘Max’, was also used during the Blitz. The smaller bombs were often fitted with a device, the Gerät Jericho (Jericho apparatus), which emitted a wind-induced shriek similar to that of a German Stuka dive-bomber to intimidate their human targets.

Other bombs developed by Germany included two radio command types (see guided weapons); a concrete-cased bomb containing scrap metal; a rocket-assisted bomb for attacking fortified targets, which the British also developed; and the lethal 2 kg. (4.4 lb.), 9 cm. (3.5 in.) anti-personnel Splitterbombe (splinter bomb). Called the butterfly bomb by the Allies, it was copied almost exactly by the Americans. It could not be defused and was delivered one hundred at a time in a container, which was dubbed a ‘Molotov bread (or egg) basket’ by the Finns who had been on the receiving end of a similar device during the Finnish–Soviet War.

Only the British, whose three main types of HE bomb were the General Purpose (GP), Medium Capacity (MC), and High Capacity (HC), produced bombs bigger than the 2,500 kg. ‘Max’. The higher the capacity the higher the charge-weight ratio, the charge of some HC bombs being as much as 80% of their weight. This gave them very thin casings which resulted in a high blast effect but minimum penetration. Over half a million 500 lb. (225 kg.) GP bombs were dropped by RAF Bomber Command during the strategic air offensive against Germany (see Table), but they were less efficient than their German counterparts having a lower charge-weight ratio. As a result of the shortcomings of GP bomb, 500 lb., 1,000 lb. (450 kg.), and 4,000 lb. (1,810 kg.) MC bombs were developed but were often in short supply. The biggest breached the dykes on Walcheren Island in October 1944 during the Scheldt Estuary battle. The 12,000 lb. (5,430 kg.) ‘Tallboy’ or ‘Earthquake’, and the 22,000 lb. (10,955 kg.) ‘Grand Slam’, were also MC bombs. HC bombs came in four sizes—2,000 lb. (905 kg.), 4,000 lb., 8,000 lb. (3,620 kg.), and 12,000 lb.—and were known generically as ‘blockbusters’. The British also developed HE bombs for special targets, the most famous being the bouncing 9,250 lb. (4,195 kg.) cylindrical, rotating bomb invented by Barnes Wallis for the Dam Busters raid.

By 1945 Allied HE bombs had increased in power five-fold. But by then, on an equal-weight basis, incendiaries such as the US 70 lb. (30 kg.) M47, which used napalm, were far more effective, though the liquid-filled British 30 lb. (13.6 kg.) ‘J’ bomb, first used by RAF Bomber Command in April 1944, was a failure as it often failed to work. Early British incendiaries filled with thermite—a mixture of iron oxide and powdered aluminium—produced great heat but this dissipated quickly and was confined to a small area. The Germans overcame this with their highly effective 1 kg. (2.2 lb.) bomb by making thermite its primary igniting substance and metallic magnesium the principal incendiary material. This made it burn with great heat for a long time and it could not be doused with water.

Japan produced an incendiary bomb of a radically different design. It contained more than 700 open-end iron cylinders filled with thermite and was fused to burst at about 60 m. (200 ft.) above the ground which scattered the cylinders over a radius of 150 m. (500 ft.).

Bombs: Numbers and types of bombs droppedby RAF Bomber Command, 1939-45, duringthe 389,809 sorties flown. The total came to955,044 tons.

Type	Total no.
Source: Macbean, J. A. and Hogben, A. S., Bombs Gone, (Yeovil, 1990).
Fragmentation (F)
20 lb	5,000
General purpose (GP)
40 lb	42,939
250 lb	149,656
500 lb	531,334
1,000 lb	82,164
1,900 lb	2,141
4,000 lb	217
Semi-armour-plercing (SAP)
500 lb	11,600
Armour-piercing (AP)	Exact figure is
2,000 lb	not known but less
	than 10,000
High Capacity (HC)
2,000 lb	28,633
4,000 lb	68,000
8,000 lb	1,088
12,000 lb	193
Medium Capacity (MC)
500 lb	403,000
1,000 lb	253,800
4,000 lb	21,000
12,000 lb Tallboy	854
22,000 lb Grand Slam	41
Incendiaries
4 lb	80,000,000
25 lb	20,000
30 lb (Phosphorus)	3,000,000
30 lb ‘J’	413,000
250 lb	7,000

The 4 lb. (1.8 kg.) incendiary filled with thermate—a mixture of thermite and oxidizing agents—was the one most used by the Allies, almost 30 million being dropped on Europe in special containers called clusters. Almost 10 million were also dropped during the strategic air offensive against Japan, though the most frequently employed was the 6 lb. (2.7 kg.) M69 oil bomb which had cloth ribbons instead of metal fins. It acted like a small mortar, ejecting its filling of napalm several yards after being dropped in clusters, and it was these that burnt out 41.5 sq. km. (16 sq. mi.) of Tokyo in March 1945.

Mills bombs, sticky bombs, and Gammon bombs were not bombs but hand GRENADES.