BBC - WW2 People's War - Parachute Mines In this account it describes bombs being dropped by parachute on Coventry, the sc1800 was a conventional bomb, not a sea mine.
Allied/Axis Bomb-Shapes
- Thread starter Zipper730
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An unexploded bomb with a timing device is a bigger nuisance/problem than the bomb itself. If you read the account, large areas of the city were cordoned off and some exploded anyway killing those trying to defuse them, dropped by parachute they were a surface blast which frequently caused more damage than a bomb penetrating the ground.
In the case of bombs with a very light case and therefore a high explosive content it is very likely that the explosives will spill out as the case breaks up on impact before the trigger ignites the primer ignites the explosives. This greatly reduces the effectiveness of the explosion. Also there is a likelihood that the bomb will partially burry itself in soil before triggering which will also absorb its energy.
Whereas a human parachutist falls at about 25fps (7m/s) these mines fell at either 70fps or 220fps (I've heard both)
The SC 1800 was just a standard bomb, it was dropped by parachute for terror and disruption not for some theoretical reason of velocity and energy distribution. Yesterday you didn't know it happened now you are explaining the theory of why it did, a while ago you argued that they were naval mines that missed the sea, what is your game here? Parachute mines were and are part of British WW2 folk lore they had a much greater effect on the population's psyche than conventional bombs as you can see if you read the links I posted.
Ok thanks, I accept that parachute bombs were used. You were right. Nice to see some primary documents. There might even be a reference in Wolfgang Fleischers "German Air Dropped Weapons to 1945"
I didn't make this up, A historian at a British Museum mentioned it on YouTube documentary about a month ago as we were debating that Opperation Sea Lion stuff. I think now he was referring only to its initial use in dock attacks during the BoB as bombing escalated on both sides. YouTube deleted my account over some TOS issue and I've lost my history.
Sea mines may have been used initially to mine ports but some missed and it was noted that they were probably more disruptive and destructive dropped at random on cities.
The parachute mines were used to prevent the case from splitting open before detonation or to stop the bomb penetrating the ground before detonation. I think we'll find I will be right on this. Note the British used them as well in the early war years.
Clockwork delays of up to 6 days were fitted to some LMB used over land but the bulk at least initially exploded on impact or within a about 10 seconds. Most of the clockwork delays Ive seen in Fleischers German air dropped weapons are for a few minutes to max 2 hours. Keeping the bomb intact so that a time delay may be used was one probable reason but I would refer to it as more a harassment than a terror though I wouldn't deny that there would be a feeling of terror. A parachute bomb, sitting on the surface with its parachute draped around the area with a time delay would very easy to see, walk away from and avoid thereby reducing casualties. One the other hand it would need to be defused or sand bagged meaning that the street, factory etc where it fell could not be opened.
Smaller non parachute retarded bombs such as the SC250 or SC500 often had short time delay fuses (several seconds, these were the electrically programmed fuses) so that if the aircraft was dropping low (which Ju 88 often did) the aircraft could clear the area.
A significant proportion of UXB (a TV drama I remember) would also be just faulty detonators.
There was an attempt by the Luftwaffe to adopt the FuG 101a altimeter into a proximity fuse called Marabu.
The ELAZ electric fuses usually had time delays of less than a second designed to assure penetration but one type could be programmed for around 15 seconds.
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I agree. The story is that after the sea lane and harbour mining campaign against Britain stopped, in part because the British developed several effective anti mine measures such as degaussing, there was a surplus of these mines. The cases were then used over land where they were very effective due to their being able to detonate above ground, their high explosive content and the issues I noted such as not spilling out or burying themselves in soil. The mechanical clockwork timer was latter added as a harassment device.
There was also a parachute adaption known as the SC 1000 parachute. Not sure if this was to ensure above ground detonation of for low level attack purposes.
The LMB was also latter improvised as a parachute delivery container known as a Mischlastabwurfbehelter 1000 with a shock absorber nose. (Mixed load container). There were properly engineered parachute delivery containers for fuel, ammunition, supplies as well, very neat with man transportable containers inside for ammunition, food and fuel. It's said that when Jenkonshenk told Hitler that the 6th Army surrounded at Stalingrad could be supplied by air he had incorrectly assumed the various containers could actually carry in kg the 'number' at the end of the designation. While generally this number refers to the approximate weight of the bomb it more properly refers to the bomb shackles mount. Mischlastabwurfbehelter 1000 certainly couldn't carry 100kg of Ryebread, Bacon and butter. I'm sure there was more too it than that.
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I can not see the advantage of cylindrical, box or plain fins except maybe strength or some modest length reduction. So long as the fins stabilise the bomb in the forward direction and rotate it slightly so that it evens out any minor differences in manufacturing and it falls in a consistent way it will be enough. The Luftwaffe bombs tended for 4 simple plain fins.
The US M65 500 lb GP bomb if dropped from 20,000ft/6096m at 200mph (90 meters sec) will hit the ground in about 37 seconds as opposed to the 35.2 seconds of the vacuum trajectory. The trail of the bomb under the aircraft in a vacuum would be 3330m and the bomb trail error due to air resistance will be 300m. In other words the bomb trail error is 9% of the vacuum trail and the time to fall is 4.5% longer. There is probably a Coriolis effect as well.
A more aerodynamic bomb with the same weight and half the Cd would roughly halve these percentages. Any variation in air density, manufacturing variation, head wind will have halve the effect of error from those published in the bombs trail error tables.
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