Or all the planes would have to converge on the same spot of sky at point of release.
British Bomb Sights
- Thread starter pinehilljoe
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swampyankee
Chief Master Sergeant
- 4,022
- Jun 25, 2013
Heck, it was a problem in the daytime. Rudely, the Germans had disabled all the aids to navigation. Dropping from 25000 ft to check road signs wasn't particularly safe or effective.
I have regularly flown over Europe with it completely blanketed with cloud, without navigation aids you are frequently no better off by day than by night. Pollution or "industrial haze" was a bigger problem then, since towns were burning coal they were covered in a cloud of smoke on still days.
Shortround6
Major General
A copy of Bradshaw's was an essential part of any British navigators kit between the wars.
Only part kidding, following the rail lines was an all too common method of navigating in the absence of better equipment during the 20s and 30s.
The British putting a bit too much faith in "it'll be alright when the shooting starts".
They may not have been alone. A lot of countries auxiliary equipment (navigation, communication, cabin heaters and even gun heaters being more or less lacking when the shooting started)
Brooke
Airman
Iron bombs never worked in a precision mode and never will.
Gyroscopes
TED: Malcolm Gladwell: The strange tale of the Norden bombsight
Even today there's debate on how to shoot a rifle at 1,000 yards:
FN FAL Rifle
All the things that effect bullets also effect bombs, torpedoes & artillery shells. But a lot of these were unknown in W.W.II.
Gyroscopes
TED: Malcolm Gladwell: The strange tale of the Norden bombsight
Even today there's debate on how to shoot a rifle at 1,000 yards:
FN FAL Rifle
All the things that effect bullets also effect bombs, torpedoes & artillery shells. But a lot of these were unknown in W.W.II.
As a philosophical exercise you may have a point. However, in practice, the individual AC could not occupy the same location at the drop point, therefore, even if the drop was ideal for all AC, a certain variation due to their separation would produce a shotgun pattern. The other real world variables would contribute to the distance between bomb clusters from a single formation. The US developed formations that required only 2 planes, lead and deputy lead, to actually carry Norden sights. Those experienced crews would aim and the rest of the formation would drop when they did. The formations would tighten up their 3 dimensional squadron elements entrail between the IP (initial point ) and the AP (aiming point). This produced a pattern of bomb clusters close to those of the lead crew, walking through the target... in theory.
It's interesting that the Norden Bombsight was kept out of British hands for most of the War, even American aircraft that were fitted with it (like the B-17, B-24 etc) had it stripped out before being delivered to the British. This is despite a personal plea from Neville Chamberlain to Roosevelt at the begining of the war. It was not until November 1944 that the RAF was leant some, along with an experienced American bombardier (Captain Stroud USAAF) and a representative of the Norden company (Mr Mitchell). They were tested by the RAF Bombing Development Unit at Newmarket using Mosquito XX KB268 (the sights provided were the M series). The results were not good - The official RAF report used the phrase "shocking inaccuracy". It was inferior in every way to the British SABS sight and the trials were cut short. - The file in British records is AIR14/875 - A short precy was published in the Air Britain "Aeromilitaria" magazine Issue 130 Summer 2007 in the "Out of the Archives" column.
Direct quotes from the BDU report in blue.
The British (BDU) found that the installation of the Norden in the Mosquito was 'very neat and practical and makes the best use of the restricted space'.
The causes of the 'shocking inaccuracy' were inconclusive and suspected as being 'due to the unavoidable accelerations in the somewhat unstable Mosquito'. Just the way the Norden functions and the fact that 'the Norden sight is far more complicated to use than the S.A.B.S.' killed any thought of its application to Mossie use. They figured it wasn't worth extending the trials to find out exactly why the Norden-Mosquito interface wasn't performing.
That isn't to say this was representative of how the Norden performed on an aircraft like the Fortress, renowned for being a rock-solid bombing platform.
wuzak
Captain
The other factor with the Norden was that it required a longer straight line approach than the SABS of Mk XIV.
wuzak
Captain
The Course Setting Bomb Sight (CSBS) Mk IX was found to be unsuitable for the Mosquito because its maximum speed setting was 240mph TAS, whereas the Mosquito could bomb at 300mph.
It was recommended to use the MkXIV CSBS. Using the MkIX required the use of fudge factors for speed and altitude.
The Legendary Avro 6 Bomb Carrier for the Mosquito
It was recommended to use the MkXIV CSBS. Using the MkIX required the use of fudge factors for speed and altitude.
The Legendary Avro 6 Bomb Carrier for the Mosquito
Allan Hunter
Airman
- 45
- Jan 30, 2020
The high precision attacks on the submarine pens and on the Tirpitz used the later bombsights. I believe this was the SABS. In the early years, and for area bombing, the RAF used the Course Setting Bomb Sight Mk VII for slow aircraft and the Mk IX for faster aircraft. There was also a later Mk X, which was not widely used, before the introduction of the Mk XIV - which was a whole new development.
I have a couple of the early Mk IX sights I'm trying to complete, and I'm always looking for parts and information.
swampyankee
Chief Master Sergeant
- 4,022
- Jun 25, 2013
Possibly. A spy had provided nearly a full set of plans for the Norden bombsight to Germany before US entry into WWII
special ed
2nd Lieutenant
- 5,667
- May 13, 2018
I read in one book that the Germans had preliminary diagrams stolen in 1937 but decided it was overly complicated.
Wolfgang Samuels "American Raiders" says that the American teams that interviewed the chief engineer for at Zeiss says they never saw a Norden until 1943, that's 2 years after the Lofte 7A entered service in 1941. If you look at the two sights they are very different. The Lofte is far more compact and in an all in one package.
A German espionage operation that needlessly lost assets did pointlessly obtain Norden drawings but they made no use of it.
The Lofte 7 was far more compact and easier to maintain since optics and computing mechanism were in one unit and this keep it all calibrated. The Lofte was produced in different minor variants to deal with different altitudes and speeds. The Lofte 7 could begin tracking the target much earlier than the Norden.
The mechanical computing techniques used in the Norden were well known from FLAK, predictors, naval big gun computers and torpedo data computers well known to the British, German etc. That they were developed first in the US probably gets down to engineers from the US Navy Buro of Ordinance being familiar with big gun computers such as the Ford Range Keeper and AAA predictors and being receptive to the idea of applying this to level bombing sights used in naval aviation. They didn't just need to compensate for cross winds and head winds but target motion.
I am rather surprised that Udet, Milch, Jenkoschenk Continued with their dive bomber focus without considering the power of these computing sights witch must have been under development in 1939/40 in Germany.
The Norden seems to have been flexible and add one were designed to allow bombing while climbing or descending.
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pinehilljoe
Senior Airman
- 742
- May 1, 2016
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In spite of the security precautions, the entire Norden system had been passed to the Germans before the war started. A member of the German Duquesne Spy Ring, Herman W. Lang, who had been employed by the Carl L. Norden Corporation (manufacturers of the Norden bombsight), was able to provide vital details of the new bombsight to the Abwehr. During a visit to Germany in 1938, Lang conferred with German military authorities (Oberst Nikolaus Ritter of the Abwehr) and reconstructed sketches and plans of the confidential materials from memory.
Basically the Abwhere spied on something various German companies already understood and could make and did make albeit in the form of triaxially stabilised tachymeric naval gun directors, FLAK predictors and Torpedo Computers. The Abwhere would have been better of not wasting its agents on such trivialities. You would only learn the capability of the device (usefull). Perhaps it spured on the contracts for the Luftwaffe to develop and acquire its own. Every other combatant developed its own wind correcting computing bombsight. The RAF (SABS II, Mk 14), Luftwaffe (Lofte 7, StuVi 5B), the Soviets and Japanese had them as well.
The US had them first so what is interesting is not that the US had the capability to build this instrument, everyone else could, but that there were officers in the American military who actually supported its development and acquisition.
Clayton Magnet
Staff Sergeant
- 902
- Feb 16, 2013
Interesting to note, that even in the post war period, with access to the Norden and the SABS, the RAF decided to stick with the Mk.XIV on the V Bomber program
The "trick" of bombsights like the Norden, Lofte 7, SABS-II was that the target was tracked by the bomb aimer for a while. This revealed the aircrafts drift due to head and cross winds. They were "tachymetric".(speed measuring) . This allowed offsets to be added in. It also tracked moving targets like ships. Sights like the Mk 14 on the other hand worked by calculating where the bomb was going to go so they worked while the aircraft was manoeuvring. It could even shallow dive bomb. It couldn't calculate wind speed, that was entered manually.
However as soon as Doppler radar came in for navigation, like it did on the V bombers, the cross wind drift speed was available from radar and the inertial navigation system. I don't know how wind speed was estimated. Maybe pathfinders, maybe H2S.
