WW2 Bomb Sights... which was the most accurate?

Discussion in 'Military History and Militaria' started by uncle_vanya, Aug 15, 2010.

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  1. Just a query. I have an interest in the USAAF in East Anglia during WW2, and often visit some of the old airfileds. One or two have renovated control towers that have been turned into memorials/musuems to the memory to those USAAF personel who served at them during the last war. One of these Tower Museums has a complete Norden Bomb sight on display.

    I was curious to read that the USAAF treated their Norden Bomb Sight as 'Top Secret'. After, and before each bombing sortie, the Norden sights were kept in a a secure, guarded building on each base.

    Has there ever been any statistical research carried out as which of the Allied WW2 Bomb sights was the more accurate. The Norden or the RAF's MKX1V, or the German Luftwaffe Lofte Bombsight?
  2. The wiki says some kraught working in the factory leaked the design to Germany in 1938 and that the Lofte was based on it.
  3. maguire

    maguire LE Book Reviewer

    I recall reading in paul brickhill's 'The Dam Busters' that the 617 senior bombaimer didnt rate the Norden at all - I cant recall offhand what 617 were using but I believe they were getting phenonemal accuracy by comparison on their 'Tallboy' and 'Grand Slam' sorties.

    the USAAF's tactics of dropping in formation didnt do them any favours either I understand.
  4. 617 Sqn were using the Stabilizing Automatic Bomb Sight by then. More on that and other British bomb sights including the MkXIV here:

    BC - Major Bomb Sights
  5. the_boy_syrup

    the_boy_syrup LE Book Reviewer

    Often only the lead Navigators plane had the Norden so when he dropped all the other aircraft droped
    Hence due to teh bomber stream being a mile wide and two miles long the whole ton was flattened

    Despite claiming to be able to hit a pickle in a barrel (hence why bomber crews refere to pickling when the bombs are gone) what worked well in training in Arizona soon became a different hing when the formation was bouncing all oer the sky

    IIRC I read somehwre that Grand Slam and tall boy droped straight down from the aircraft so crews flew over the target and just dropped it straight onto it
    They had to pull up sharpley to fire it forward like a normal bomb
  6. Apparantley most bombsight's were pretty much of a muchness i.e. if you could see the target and have perfect conditions you would hit the target (maybe).
    American's norden bombsight was said to be the most accurate (drop a bomb in a pickle barrel was the saying), but it was tested in a desert with no cross wind no flak and no pesky fighters.
    The main advancement was Radar Guidance (Oboe).
  7. The laws of physics make this impossible, at the moment of release any bomb is travelling forwards at the same speed as the aircraft dropping it. It then begins to decelerate in the horizontal plane depending on its drag co-efficient, in simple terms dustbin bombs like the 4-8-1200lb "blockbusters" [technically High Capacity] would slow down faster than something with an aerodynamic shape like Tall boy and Grand Slam. All bombs fall at pretty much the same acceleration due to gravity so the TB/GS would actually have landed further from their release point than the HC types. In addition I suspect that the Grand Slam had the Lancaster so close to its load limit that to pull up sharply was not an option.

    The accuracy of the bomb site is mostly dependant on the accuracy of the information put into it because free fall bombs pretty well follow some simple laws of physics. So if you can accurately input the speed of aircraft, the bearing of the aircraft, including up or down so level = simplest, the vertical distance to fall [the altitude of the aircraft less the altitude of the target related to a common datum, the wind speed and direction [throughout the complete trajectory, it will change between ~24,000 feet and sea level] and the drag co-efficient of the bomb you will get a pretty accurate result. In reality all of this data was, even in 1945, a good guess so when you allow that all the errors might multiply together in the same direction you understand why all sides used area bombing. If you really needed accuracy you went in very low or used dive bombing methods but neither of these worked with heavy bombers for obvious reasons.
  8. From what I remember, another problem with the Norden sight was the fact that it was brilliant during sunny, cloudless days. Unfortunately, there not being many of these over Central Europe, and there being very many cloudy, sunless ones, it was as useful as a chocolate fireguard. At least, that is what I seem to remember. Is there any truth to that or am I going prematurely senile?

  9. the_boy_syrup

    the_boy_syrup LE Book Reviewer

    No thats correct all the USAAF trials were done in places like Arizona
    TYhey could drop a bomb accuratly from height
    Over Germany cloudy fighters flack the whole formation bouncing up and down it wasn't as good
    Plus in most cases only a couple of the aircraft carried it most just dropped when the leader dropped

    One of the things about the precision bombing claim was that it was propaganda based
    By claiming they were aiming for a factory say they could clam hat any other damage was incedental (collatarol now a days)
    Where as the British just flattened the whole town to hit the factory

    Worth remembering that the main battle was actually getting there in the first place
    One of the USAAF Sqns on the follow up raid to Dresden missed it due to the smoke and ash clouds and bombed Prague
  10. In September 1944 on the joint 617 and 9 Squadron mission to sink the Tirpitz, 617 were using SABs and 9 were still using the Mk XIV. During the practice missions there was reportedly very little difference in bombing accuracy.

    It was seemingly all down to practise and good concentration by the bomb aimers.

    Disadvantages of SABs were that it required the ac to make a long straight run in making it an easy target for flak. Also 617 couldn’t de-calibrate them. After much practise all the bomb aimers were putting the bombs into the same crater!
  11. I understand that that is the reason why the Americans restricted themselves to daylight bombing. The sight was next to useless at night.