Bombs dropped by Luftwaffe aircraft largely comprised either high explosive (HE) or incendiary, although there was also a range of specialist bombs. The former were designed to deliver a blast effect, shattering or demolishing buildings and structures, the latter setting fire to flammable materials.
Very often the two weapons were used together, often as composite loads in the same aircraft, the incendiaries being used to exploit the opening-up effect of the HE, exposing otherwise protected materials.
Early in the war, German HE bombs (known as Sprengbombe) were often of low weight, 50kg being the most common type. Another widely used type was the 250kg, but heavier weight bombs were also used.
The type was identified by a prefix, either SC, SD or PC, according to function. The number would specify the weight in kg, so an SC50 would be a 50kg Sprengbombe Cylindrich.
In addition to type and weight designations, HE bombs sometimes carried a suffix to indicate the type of fuze or zünder employed, i.e,. mV = mit Verzögerung (with short delay action) and LZZ = LangZeitZünder (long time delay). Thus, for example, the designation SC250 LZZ identified a general purpose, high explosive bomb, weighing 250kg and fitted with a long delay fuse.
The thin-cased general purpose was called the sprengbombe cylindrich (SC). Used for blast effect, they had a relatively high charge ratio of 55 percent. Used primarily for general demolition, something like 80 percent of German high explosive bombs dropped on the UK were of the SC type.
This picture immediately above gives the relative sizes of the bombs. From front to back are the 50k, the 250kg, the 500kg (in the wooden frame), the 1000kg (nicknamed by the Germans "Hermann") and the 1800Kg (nicknamed by the Germans "Satan"). The bomb right at the back appears to be a 50kg variant.
The picture at the top has 250kg bombs being "decorated" by Luftwaffe personnel, giving some clues at to the size. The bomb is actually 64.5 in. Its filling is either 60/40 Amatol/TNT, or TNT with a variety of additives including wax, woodmeal, aluminum powder, naphthalene and ammonium nitrate. The weight of the filling is 287lbs, making 52 percent of the total weight of 548lbs.
The picture below shows a pair of 1,000kg "Hermann" bombs, in front of a wrecked He 111. The two represent the maximum bomb load for this aircraft type.
Specialist bombs used included the thick cased semi-armour piercing type, known as the Sprengbombe dickwandig (SD). These were medium cased steel weapons and, being either anti-personnel or semi-armour piercing, had a load factor of 35 percent explosive. Because of their penetration qualities they were used primarily against ships and fortifications. These also came in a range of weights, ranging from 50, 250, 500 to 1,700kg.
There was also the armour piercing bomb, known as the panzerbombe cylindrich (PC). With a thicker, armoured steel casing, as little as 20 oercent of the total weight was explosive. It was used against shipping - and especially warships - and fortifications. The heaviest used was the 1,400kg "Fritz" version.
Another air-dropped device was the parachute flare, or licht cylindrische(LC50 ). These were approximately the same size as a conventional SC50 bomb. They were used for target illumination and marking at night.
By their intended recipients, these were referred to as "Land Mines", often with some awe, reflecting the amount of damage they could do. With a high charge ratio of 60-70 percent and parachute-retarded descent, they created considerable blast damage in built-up areas. The 1000 kg Luft Mine B was normally employed, and as such was designated Bomben B when used against land targets (see right - an unexploded version).
Below is an indication of their destructive power, evident from the size of the crater. An air burst could often demonish a complete block of houses.
Although the available HEs possessed great destructive power, perhaps the most potent bombs remained the incendiary which, dropped in profusion in 1940/41, caused millions of pounds worth of fire damage and virtually burnt out whole districts of British cities. However, since they were so often used in combination with blast bombs, the two together could be regarded as a composite weapons system.
The type used in the Battle of Britain was the tiny B1El, a 1kg bomblet known as the brandbombe, 1kg Elektron, hence B1El. The consisted of a cylinder of Magnesium Alloy (Elektron), with an incendiary filling of Thermite. These weapons, which burnt with a heat sufficient to melt steel, were ignited by a small percussion charge in the nose which fired on impact.
In an attempt to make these weapons even more effective, and to defeat the fire-fighters efforts, the Germans introduced explosive charges into the nose or tail of some incendiary bombs.
The charge was initiated either by the heat of combustion, or by a more complicated device that incorporated a delay of about 7 minutes. The various versions of this bomb included the letter Z in their designation, indicating explosive charge. Thus the standard B1El incendiary bomb fitted with an explosive charge detonated by heat was designated B1EL ZA, and that detonated by a delay B1El ZB.
The Luftwaffe used various types of containers to carry and drop small incendiary bombs and in the early part of the war these were usually expendable, aimable types, designated AB (Abwurf Behalter) or BSK (BombenSchaltKasten), holding some 36 B1Els.
Dropping was enabled by an ESAC 250/IX cartridge. The ESAC 250 is an abreviation for (in German) Elektrische-Senkrecht-Aufhangung fur Cylinderbomben 250/IX. In English, this is "an electric activated vertical bomb rack system mark IX for cylindrical bombs up to 250kg. "An He 111 bomber was equipped with eight ESAC 250s in its internal bomb bay, giving it a carying capacity of 2,000kg.
It was possible to load into the cartridge one 250kg bomb or 4 x 50kg bombs, using an adaptor. This would permit loading four BSK-36 incendiary containers. With each containing 36 incendiary devices, theoretically, an He 111 could carry 1,152 of them. In practice, it would carry a mixed load.
The original large incendiary device, the so called Oil Bomb which was known to the Germans as the flam or flammenbombe. It contained an oil mixture and a high explosive bursting charge.
These weapons, based on the 250kg and 500kg high explosive bomb case, were thus designated Flam 250 and Flam 500. They were fitted with an impact fuse which often failed to detonate. This resulted in the case splitting open to disgorge its contents without igniting, and as a result of their reliability they were withdrawn from widespread use by January 1941.