WWII British Bombsights: Getting on Target

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As bomber aircraft began flying higher and faster during the First World War and the interwar period, it became necessary to develop sophisticated mechanical bombsights to help maintain bombing accuracy.
The two most common bombsights used by the Royal Air Force during WWII were the Mk.IX Course-Setting Bombsight (CSBS) and the Mk.XIV sight, which worked on the vector principle - distinct from the tachometric principle used by the more famous U.S. Norden bombsight.
Mk. IX Bombsight Tutorial: • Wimperis/Course Settin...
Norden Bombsight Training Films:
• PRINCIPLES OF OPERATIO...
• OPERATION OF THE NORDE...
• Norden Bombsight - Ope...
• Norden Bombsight - Con...
• Norden Bombsight Princ...

[@phillipdoorbar1615]

The box you call the bomb distributor only controls the rate at which the bombs are dropped. The order in which they are released is set by another device on the bomb aimers panel. It has 16 wheels with 16 positions on each (there are actually 15 storage points in a Lancaster bomb bay). So if you want position 13 to drop first (13 is in the middle of the bomb bay and typically held the 4000lb cookie) you would dial ‘1’ onto disc ‘13’, and so on for the other stations holding a munition. I joined the RAF in 1970 as an Electronic Fitter, Navigational Instruments, and one of the modules we were taught was ‘Bombsights and Gunsights’ and the MKXIV was still on the curriculum!!

[@ajaxjs]

That's amazing.

[@kingcosworth2643]

My Grandfather was a navigator in Bomber Command during the war, 692 Squadron fighting in a MK XVI Mosquito which is the high altitude 4000lb bomb variety. He flew 39 sorties, 19 over Berlin and earnt himself a DFC. I loved his stories from the war, I was mesmerised, I saw a doco in America once and they mentioned how amazing and superior the Norden bomb site was. When I got back to Oz I asked Grandad about how good where the American 'bombing computers' were. He said they where useless and they didn't use them. He said that they worked very well over the deserts of Arizona and New Mexico, but when subjected to the hilly terrain and overcast weather of Europe they where rendered pretty well useless. He was the most. He was the most non-mechanical man on the planet but he had a passionate love for the DH Mosquito, I asked what is was specifically about the aircraft and he simply said, 'it always got me home', he also said the German flack use to look really beautiful, he was 18 at the time, only way you could think that while an entire country was trying to kill you. In the 90's he was watching a WW2 doco and it was mentioned that the MAN factory in Berlin was bombed which he thought was amusing because that was him, his target with a 4000 pounder 'I sent it through their front door'. I miss my Grandfather.

[@nickdanger3802]

"I sent it through their front door" A good trick in darkness. "To destroy the German aircraft industry, for example, precision bombing was needed, and in this the Americans specialized. The United States Eighth Air Force had been trained to bomb by daylight using the most accurate bombsights which could be devised, and with these they might reasonably be expected to hit buildings, such as the Messerschmitt assembly plant at Augsburg or the Vereinigte Kugallagerfabrik at Schweinfurt. Bomber Command,m since it could operate in strength only at night, was not in a position to follow these tactics. The navigating device 'GEE'; was in operation and increasing in efficiency almost nightly, but 'H2S', 'OBOE' and the other scientific devices by which a greatly increased degree of accuracy would, it was hoped, be achieved, had only just been introduced. The bombing on a heavier scale of industrial targets situated in cities was, therefore, Harris maintained, the only alternative if his Command was to make an adequate contribution to the common effort. This was recognized in the 'POINTBLANK'; Directive, in which it was stated that the primary objectives of Bomber Command were unchanged." page 4 Hyperwar Royal Air Force 1939-1945 Vol III

[@douglasfur3808]

The Norden might not have been the best bomb sight but it had the best sales pitch of the war. The joke was that its super top secret status was to keep people from learning how it wasn't as good as advertised.

[@nickdanger3802]

IWM 1942 "Accepting that precision bombing was proving impossible, the War Cabinet sanctioned 'area bombing' - the targeting of whole cities to destroy both factories and their workers. It was judged necessary to defeat an enemy that seemed on the brink of victory." RAF Bomber Command During The Second World War page

[@jacksprat9172]

Indeed, keep the kickbacks to a minimum.

[@usvalve]

And I thought you just estimated and pushed the button! Incredible "analogue computers", you must have needed a thorough training course to remember how to work them in a bomber at night.

[@michaelbevan3285]

early bombsights were more akin to slide rules than anything else. the bomb aimer added in what he knew which was airspeed, altitude, weight of bombs, estimated flight time of the bombs and temperature at his altitude and a guess at wind drift. Quite often, the first bomber dropped his load and the rest dropped on his cue or simply dropped as near to his bombblasts as possible.

[@nickdanger3802]

"The technique of attack had been worked out with great care. An advance force would drop flares for fifteen minutes, relying entirely on GEE and ignoring visual impressions in order not to be misled by decoys. Two minutes after the first flares went down, other aircraft of the advance force would start bombing with incendiaries, taking as their aiming point the big square in the centre of the old town. After fifteen minutes the main force would begin to arrive, and would pile down its bombs on the fires already burning. The tactics, in other words, were to be a form of pathfinder/fire-raiser technique; but whatever the Luftwaffe had shown us of these methods in the autumn of 1940 was to be far surpassed. For even if the town was completely obscured by cloud, GEE, it was thought, would ensure that at least one bomb in two found its mark. On the night of 8th/9th March conditions promised well, and 211 bombers, of which eighty-two were equipped with GEE, took off for the great attack. The first wave arrived punctually and duly dropped their flares on GEE fixes. The weather held good, apart from the inevitable industrial haze. Unfortunately, many of the incendiaries were dropped after the flares had burnt out. Scattered fires therefore sprang up, and these seriously misled the main force. The result was that though 168 aircraft claimed to have bombed the target area, the brunt of the attack fell on the Southern outskirts. Many bombs also struck the neighbouring towns of Hamborn, Duisburg and Oberhausen. In the Essen area the local authorities noted the fall of 3,000 incendiaries and 127 high explosive bombs, and reported appreciable damage to engineering works, railways and houses. Krupps was virtually untouched." --124-- Hyperwar Royal Air Force 1939-1945 Vol II

[@philspencelayh5464]

Interesting video, a lot more to it than you might expect. Watched this after watching one about the Norden and I'm pleased that the RAF didn't adopt that.

[@billyhouse1943]

Thank you. Very informative and something that a lot of people never knew about “computer” usage in WW2.

[@samcruickshanks6856]

This is a result of big gun battleships and the mentality of a projectile travelling through a ballistic arch, only a few men looked at a bomb and landed on the idea of guiding the thing directly to the target itself,, via cable transmitted guiding data or via radio control, both were done earlier than people would think.

[@thethirdman225]

That was pretty interesting and very well explained. For all the claims made about bombsights, arguably the biggest problem right throughout WWII was finding the target. The bombsights you show, when trimmed accurately, were quite capable. But the spanner in the works was that early in WWII, RAF Bomber Command simply couldn't find their targets. While a lot of propaganda was expended extolling the exploits of crew destroying targets in Germany with pin-point accuracy, reports early in the war showed that only one bomb in a hundred got within five miles of the target. Even in daylight raids later in the war, bombing was often very inaccurate due to ambient weather conditions, such as inversion layers and cloud or smoke over the target area. Despite the advent of Gee, Oboe and H2S (or its American copy, H2X), this remained a problem for the entire war. In one extreme example during the bombing of Dresden, an American bomber force got confused by the smoke and ended up bombing Prague. So while the accuracy of bombsights will be forever debated - and they were very interesting instruments - their efficacy was really dependent on a much larger set of problems.

[@keithammleter3824]

As far as British bombing was concerned, they often had trouble finding the right city. As far as both British and American raids were concerned, not only was navigation not always up to it, and bomb aiming under fire from flak and BF109's not always up to it, the Germans operated very good camouflage and decoy systems. E.g., a German "oil refinery" was regularly bombed for 2 years, before it was realised that they had been bombing a flimsy and easily restored decoy and the real refinery was several miles away. The British bombed at night - this made things easier for the Germans as they would for example arrange for a lighted chemical plant to go dark as soon as the bomber course was figured out, and the lights of a dummy plant, configured to look the same, would be turned on. Often, the target would be obscured by cloud or smoke or both, as you said. Brit and American crews following the first wave figured that if you can't see the target, bomb the glow seen through the cloud or smoke - that must be the target on fire. The Germans figured that too, so they set up their own smoke making apparatus, with oil fires to create the glow, some distance away from the target in some field.

[@thethirdman225]

@@keithammleter3824 *_"As far as British bombing was concerned, they often had trouble finding the right city."_* The Americans did too. Many ruses were tried. There's a book called _"The Other War"_ by Peter Hinchliffe which describes the ways in which the RAF and the Luftwaffe spoofed each other throughout the war.

[@keithammleter3824]

@@thethirdman225 : Yes, for different reasons. The British were not as well equipped as the Americans. However, it seems that, while on paper American training was up to it - they certainly wrote very good training manuals - in combat they could loose it. I have been reading a document now available online "Bombardier's Information File" dated early 1945. In one part it has a photo taken of a factory taken at 22,000 feet at about 5 PM, alongside another photo taken at 15,000 feet at noon. Due to different shadows, roof reflectance, and different scale they look completely different! It's only after you study them for several minutes that you can believe it is the same factory in both photos. If you had to find it while being shot at, you'd never find it. I live in Australia, and am 75. In my young adult days I used to go camping with my mates in remote parts of northern Australia. These parts were and still are essentially uninhabited. On one trip we discovered an American B-25 bomber. We were by no means the only ones to discover American bombers. What happened is that during WW2 a large number of American aircraft and their crews were shipped to Sydney, which is a coastal capital. Many were ordered to fly to Darwin, an isolated coastal city on the other side of the country. It was within range if not carrying bombs. Some of them could not find Darwin and belly landed in the remote bush when they ran out of fuel. I've read a number of books on the tricks each side used in the war in Europe. The Germans tried a crossed VHF radio beam navigation system, which should have been accurate. The idea is to fly along one beam until you find the other beam. But the British radiated their own beams, "bending" the signal, thus causing German aircrews to drop their bombs in unused fields. Incidentally, when we found the belly landed bomber, we spent a lot of time examining it, 20 years after it had arrived there. We had two LandRovers. We took the batteries out of our Landies and connected them in series (ie 24 volts) to the aircraft battery 28 volt connections. The radios and other electrical equipment came alive and seemed to work perfectly!

[@diobrando2160]

@@keithammleter3824 RAF had other methods for night-bombing like Oboe and other kinds of pathfinding

[@keithammleter3824]

@@diobrando2160 ; I didn't mention them because the original poster in this thread did.

[@michaeltroster9059]

Examination and comparison of bombsights’ bombing results showed the accuracy of the Norden and the British Mark 14 we’re about equal. The Norden sight was highly over-rated and more complex to use. Actually Sperry made a better sight than the Norden, but politics made the Norden the sight the Army Airforce chose.

[@fmdj]

0:00 damn this intro really is something

[@MuttleyMutter]

Computers don't have to be electronic or digital. In the case of the Mk. XIV, it is an analog computer, a mechanical analog computer and, as you say, a pneumatic mechanical analog computer. The Sperry Central Fire Control System on the B-29 was similarly a mechanical analog computer, or rather a set of computers, one per gunsight, so five in all (one in the nose, three in the gunnery compartment and one in the tail position). In a wider context, the Admiralty Fire Control Table was also a mechanical analog computer used in Royal Navy cruisers and battleships from the mid-Twenties. Precision machining is necessary to create the components of such a device, which include gears, two and three-dimensional cams, differential mitre gears and integrating roller pickups. Temperature compensation, to allow for the expansion and contraction of the metal elements, also needed to be included.

[@moagnor]

Ive never thought of that bomb releasing pattern machine, but it was pretty interesting. And its pretty obvious that youd need something like this when you release so many heavy bombs from a "relatively small plane". The WW2 was the first "technological war". Where technology was used. Like the computer bombsights. Even though it is never mentioned there is also the morale aspect: Knowing that the bombsights was accurate must have made it easier for the bombing crew to release bombs on cities, knowing that as few civilian casualties would be possible. (Even though that accuracy was not so in practical situations). The film Memphis Belle is one of my favorites, and its the first one where you can see the problems with the bombsights and bombing. Film before that one you just see the bombs away.

[@dougerrohmer]

The RAF was actually trying to hit the civilians. There were missions were the firebombed workers' housing areas, and then came back a while later to bomb the parks and areas where the civilians were evacuated to since their houses were on fire. Bomber Harris is rotating on the spit in hell right next to Himmler et al. But, as they say, war is hell.

[@KellyClowers]

> The WW2 was the first "technological war". Where technology was used I hate to break it to you but catapults are technology. Guns are technology. A bow and arrow is technology. A chariot is technology. A knapped blade instead of just a random rock is technology.

[@moagnor]

@@KellyClowers But, OK, everything is technology, yeah, ok ok ok, but in WWII they started using electromechanical and electronic technology to gain an advantage. WWII is often called the first "technological war" because they use techology to win the war. The bombsight is a good example of this. Radar is another. Chariots, bows and arrows is another thing.

[@RememberTheRegs]

Fascinating video. Well presented too with everything explained very nicely.

[@MrOhdead]

Fascinating thank you !

[@mandrc5562]

Very interesting video. I have a mk9 and it is nice to have some more knowledge on how it was set. Thanks.

[@bryankirk3567]

Cheers Sir.

[@Virian900]

Amazing, interesting channel and videos. You deserve WAY more views and subscribers.

[@CanadianMacGyver]

Thank you! Please spread the word!

[@DaveSCameron]

Many thanks for these uploads, you're giving me quite an education here 👍 📚 🇬🇧

[@ondrejzeman3899]

Lovely intro music... Thanks

[@ondrejzeman3899]

Well, I wrote this under the same impression thhinking that it is one of our czech compsers. Than my friend corrected me - of course it is kzbin.info/www/bejne/oZymZJaensSsqdk

[@christopherlawley1842]

Look for "Pictures at an Exhibition- Promenade (part 1)"

[@jp-um2fr]

England. Not only have I Subd and liked, I've downloaded this video. It's excellent. I have been led to believe that the Norden was not quite the wonder machine we have been led to believe. However, somewhere between 'crap' and 'perfect' you have hit it on the nose. The trouble with YD channels is the personal preferences tend to drift away from facts and go for 'hits'. You didn't. You should do one on naval gunnery. Phase of the moon, temperature, position on the planet, etc., etc. Allow around 7 hours for the video. (I jest - but not a lot) Thank you so much for this video.

[@christopherlawley1842]

617 sq. also used a couple of nails banged into a V of wood, I believe

[@dimsum435]

I think it was 3 nails actually. 😊😊

[@christopherlawley1842]

D'oh! One to mark where you look at the others!

[@flybobbie1449]

Colleague instructor, long gone now, said he flew Vampires in Aden. As a bomb sight they had lines painted on the nose of aircraft. Depending on height, as line passed target, bomb dropped.

[@thethirdman225]

One small point: in the RAF and most commonwealth services the operator was called the "bomb aimer". "Bombardier" is American. I'm guessing the RCAF used the American term. Is that right?

[@jackx4311]

When 617 Squadron was equipped with the gyroscopic bombsight, and were training to drop the 6 ton Tallboy bomb, Dr Barnes Wallis was explaining to Guy Gibson how essential bombing accuracy was to achive the full effect - i.e., wrecking the foundations of the target building, so that its own weight made it collapse. Wallis said it should land 50 yards from the perimeter wall, but when Gibson asked him what an acceptable margin of error was, Wallis said there was none; the bomb *had* to land at 50 yards. Gibson pointed out, as tactfully as possible, that achieving that degree of accuracy in combat conditions could be tricky - and the reply he got was:- "Well, if I'd known you proposed to scatter them around the countryside like grass seed, I would never have bothered to invent it in the first place!" In fairness to Wallis, he was horrified when he heard of the losses suffered by 617 Squadron in Operation Chastise (the attack of the German dams), even though Gibson assured him that the crews knew exactly how dangerous it was. After the war, Wallis was awarded £10,000 from a fund set up to reward inventors who had made major contributions to the war effort - but gave every penny to an RAF benevolent fund. When asked why he could not accept the money, he quoted a verse from the Book of Samuel in the Old Testament: "Is this not the blood of men who went in peril of their lives?"

[@nickdanger3802]

"Accepting that precision bombing was proving impossible, the War Cabinet sanctioned 'area bombing' - the targeting of whole cities to destroy both factories and their workers. It was judged necessary to defeat an enemy that seemed on the brink of victory." IWM RAF Bomber Command During The Second World War page

[@jackx4311]

So they adopted the same policy that the Luftwaffe used from 1st September, 1939 onwards. Apologists re. the bombing of Dresden, please note. Also, anyone who tells you that "Dresden was a university city of NO military or strategic importance" is . . . shall we say . . . SERIOUSLY misinformed. From the middle of 1944 into early 1945, Dresden was probably *THE* most important railway hub in the whole of Europe. Shipments heading for the Russian and Italian fronts almost all came through the huge marshalling yards and three stations in Dresden; ammunition, fuel, food, small arms, artillery, tanks, flak guns and aircraft, and troop trains - *and train loads of prisoners heading for concentration camps in the Baltic States.* If Coventry was a legit military target for firebombing in November, 1940, then the same can be said for Dresden in February, 1945.

[@philhawley1219]

@@jackx4311 Dresden also had over 100 factories producing war materiel for the Reich. If that doesn't make it a legitimate target I don't know what does

[@wmffmw1854]

The basic manual navigation tool is a B1 Manual Flight Computer (Circular Slide Rule) used in conjunction with chart, a compass and a clock. You could get anywhere with manual nav. We learned Dead Reconning Navigation as the bases of all other Navigation Systems. I flew the F4E in the 1970's. Pre GPS Era.

[@nickdanger3802]

SPAATZ: Which had the more effect in the defeat of Germany, the area bombing or the precision bombing ~ GOERING: The precision bombing, because it was decisive. Destroyed cities could be evacuated but destroyed industry was difficult to replace. SPAATZ: Did the Germans realize that the American Air Forces by intention did only precision bombing ? -5­ GOERING ~ Yes. I planned to do only precision bombing myself at the beginning. CURTIS: Was our selection of targets good, particularly oil? GOERING: Yes, excellent. As soon as we started to repair an oil installation you always bombed it again before we could produce one ton. PDF Goering Interrogation - Jewish Virtual Library

[@voya8480]

And what is happening if the bomb has wings?

[@michaeldurand6872]

Very good presentation. We have a MK9 for the Mosquito MK xx we are building.We do not have the mount. Can a copy of the plans that were shown be sent to the Canadian Historical Aircraft Assoc so that we can make one Thank you

[@CanadianMacGyver]

The diagrams are from this manual on the Canadian Museum of Flight website: canadianflight.org/files/bombsight1.pdf

[@AlecFlackie]

Correct me if I'm wrong but did the 'Black Buck' Vulcans have World War 2 era bomb-sights?

[@TrapperAaron]

Just like the brits to wait for the cover of midday sun to attack

[@highlandrab19]

Id have thought you could avoid a fair bit of these issues by putting a small parachute on the bomb so it slows and falls straight down though i guess the issue then is it being blown by the wind and being very easy to spot as it falls

[@gherkinisgreat]

Couple of problems with a parachute, firstly the wind would carry it off somewhere that isn't the target. Secondly you want the speed in a bomb so it can penetrate into the ground, buildings etc and cause more damage. Spotting it isn't a problem given buildings and railway track etc isn't going to run away

[@Splattle101]

Late to the party here (just discovered your excellent channel), but a quick point re RAF night bombing and accuracy requirements. It's sometimes said or implied the RAF had no real need for accuracy in their night area bombing campaign. This is bullshit. RAF Bomber Command strove for accuracy (bombs near the target) and precision (bombs tightly grouped), even when they were 'area' bombing. They wanted concentration in time and space to swamp the defences: to start fires so big the civil defence couldn't cope. That could only be achieved by accuracy, precision and by getting the entire raid through the aiming point in as short a time as possible. Concentration. They were not just aiming at the whole city.

[@nickdanger3802]

IWM 1942 "Accepting that precision bombing was proving impossible, the War Cabinet sanctioned 'area bombing' - the targeting of whole cities to destroy both factories and their workers. It was judged necessary to defeat an enemy that seemed on the brink of victory." RAF Bomber Command During The Second World War page

[@Eric-kn4yn]

How many hours trainning needed to qualify as bomb aimer

[@alexhayden2303]

When the reason for rifled barrels is considered, it is surprising the bombs didn't have fins to spin them?

[@philhawley1219]

Some did. Notably the Tall Boy and Grand Slam heavy bombs.

[@keithammleter3824]

An interesting talk. A correction: At 2:59 you said that trail varies with wind. It does not, as wind affects both bomb and plane. What does vary is the distance between drop and impact. You said both types discussed were successful. That depends on what you mean by successful. If you mean that the manufacturer got to sell a lot of bombsights, then yes each was successful. If you mean that each enabled the bombardier to reliably hit a specified or chosen target, then none of the British bombsights up to and including WW2 were successful.

[@michaelbevan3285]

the wind also varies with altitude. a bomb dropped from high altitude could veer left or right of the approach centreline as it dropped. Air temperature and density also come into play.

[@keithammleter3824]

@@michaelbevan3285 : True, but these effects are not in practice of as much significance as you might think. Bombs quickly accelerate to almost Mach 1 which means the time taken to traverse low altitude winds is short and thus low level winds do not have much effect. Density variation is due to variation in pressure temperature and humidity due to weather and greatest at low level and at sea level seldom varies more than about 1%. It can be neglected.

[@maxpayne2574]

Then you crossed your fingers, rubbed a rabbits foot and with luck you hit within 3 miles of the target.

[@timmeinschein9007]

The (US) Sperry bombsight was actually BETTER than the Norden! However, Norden had better connections!

[@bstrachan8527]

This is absolutely correct but not well known. The Sperrry was more ergonomic and the Norden was a nightmare in comparison. It's ironic that a whole warehouse full of Sperry sights was bulldozed during the darkest days of the war when they were desperately needed. Politics. Back in the '50s you could buy a surplus Sperry sight, including a nice locking steel case to keep it in, for $25. I bought one and it was a marvel of design and manufacture. Wish I still had it!

[@thethirdman225]

CEP of 1,200 ft but at what altitude?

[@richardvernon317]

18,000 to 25,000 feet. On the Hamburg and Dresden Firestorm Raids 500 plus bombers dropped their bombs within 3000 feet of the Target Indicators. On the Hamburg Raid, the Target Indicators landed 2 miles away from the planned aiming point.

[@thethirdman225]

@@richardvernon317 Hang on… British bombers couldn’t get to 25,000 feet with a load on. Many used flaps just to get above 20,000. Radial engine types like the Stirling, the Halifax III and the orphan Lancaster Mk II couldn’t even get that high. So presumably, the CEP was from no higher than 20,000…?

[@richardvernon317]

@@thethirdman225 Mosquito could!!! Only two Squadrons of Mosquitos used Oboe (105 and 109), 139 had a few aircraft fitted with a Nose mounted H2S from early 1944 onwards. All the rest of the Mosquito bombers in Bomber Command from 1944 onwards used the Mk XIV sight. The Standard Mk XIV sight was designed to be used up to 25,000 feet. The Mosquitos could fly up to 32,000 feet with a 2000lb load. The Mk XIV sights in the No. 8 (PFF) Group Mosquito force had to be modified to work at higher altitudes. The Trials done on the equipment in late 1944 / Early 1945 gave an average miss distance of 350 yards.

[@roum22]

That seems an awful lot of hard work when someones shooting at you. I can see the appeal of dive bombing...

[@artyzinn7725]

I love how your vids have so much info. While I appreciate seeing your face, time is spent more on as a talking head which adds little to your narration, other than showing your excellent suits and outfits. You have many good artifacts that could use detailed close ups, or usage demos pointing out details we can barely see. A great deal of your narration would be helped by simple animation or even clips from public domain documentaries, such as training films from WWII as common with Periscope films, to make your point far clearer. More power to you.

[@69degreesnorth]

Imagine how sick you have to be of missing your targets before you sit down and design an aiming computer that is basically an accordion

[@jackx4311]

Who cares if it's 'basically an accordion' - or a flute, or a tuba, or a sledgehammer? The *only* point which matters is, does it *work?*

[@hobbitomm]

No SABS? en.m.wikipedia.org/wiki/Stabilised_Automatic_Bomb_Sight