This article makes it out like gunning computers as a whole were some kind of new and revolutionary technology - while it's a feat of miniaturisation and lovely engineering, some of the earliest computers (either mechanical or electromechanical) were specifically for gunnery. Firing an artillery or naval shell 20 miles requires some pretty complex (well, if you're in a firefight - it's not that hard but it's not "oh let me think about that a moment") maths to compensate for aerodynamic effects, spin, and the Coriolis effect.
Speaking of targeting computers, one of my favorite videos on YouTube is a training film describing the theory of operation behind a purely mechanical fire control computer by the US Navy circa 1953
https://youtu.be/s1i-dnAH9Y4
I love that film, but it's kind of weird that it doesn't mention what's probably the most important invention that makes this type of computer possible: The torque amplifier.
All the devices shown suffer power losses between input and output, some of them severe. A torque amplifier has two shafts that are 1:1 geared for speed but the output shaft has extra power taken from a third supply shaft, like the supply to a logic gate that lets it drive more output power than it draws from its inputs.
Thank you for that. I just watched a few minutes, but already, watching a cam compute a reciprocal is by far the most interesting thing I've seen all week.
Analog computers were basically voodoo to me before this. Looking forward to watching the rest!
Thanks...just goes to show how brilliant some of our pre-digital forbears were. I still give more props to old school television engineers to present day ones. The laws of physics are far more unforgiving than the laws of a compiler.
If you ever find yourself near Fall River, Massachusetts, you can tour or just walk around the battleship USS Massachusetts.
One of the (many) really cool things on the ship was that you can climb into the 14" gun turret and play with an actual mechanical computer for computing range & elevation.
This confirms for me a complaint I've always had about the Millennium Falcon. A ship equipped with hyperdrive would certainly have had targeting systems as good as a B-29. There would have been no need for the midships ladders to the gun stations.
If I remember that scene correctly, the gun stations on the Millennium Falcon seem more like the B-29 sighting stations than directly operated "local control" guns (but located directly behind the remote controlled gun rather than next to it). The biggest problem that I see is that this causes the MF's sighting station's FOV to be smaller than the one pictured in the B29.
Just a random guess, but maybe it's a regulation thing. Like the empire made such military-grade weapons illegal on civilian ships. And having an illegal military-grade autocannon mounted on the side of the ship would attract attention from authorities.
Of course this is all my own rationalization: it's not like Lucas thought all the intricacies of the Star Wars universe through for their technical accuracy. This is more like literary interpretation, only instead of showing "The Old Man and the Sea" is a metaphor for the tragedy of human existence, we figure out how space ships work!
I think in one of the EU novels (Courtship of Princess Leia) Luke flies the Falcon while using both quadlasers, and if I recall correctly Han mentions that the controls in the cockpit allowed for such a thing but with a major accuracy penalty compared to having actual gunners at the gun stations. I don't recall if Luke was using the Force to make the cockpit quadlaser controls super accurate or if he was just reaching out with the Force to directly operate the controls at both gun stations.
and the same misconception populated many video games as well, yet are we not willing to trade some realism for fun and fantasy? What fun would it be if we didn't struggle? Much of science fiction in movies and games as portrayed seems to derive from WW1 fighting.
There's plenty like that in Star Wars. What about 'blasters', the weapon whose projectiles move so slowly that an alert person can physically dodge them?
Yeah, I think it was implied that the MF is heavily modified to significantly expand the capabilities of the base ship. So maybe the stock automated cannons were replaced by manual but more powerful versions.
Having blown up a tonne of them in Tie Fighter, the stock YT-1300 basically had all the fighting ability of a cabbage. The only real thing to be worried about was ramming them by accident, or possibly laughing too much to rebalance your shields.
So yes, I'm pretty sure the Millenium Falcon was heavily upgraded.
They're talking about M2 .50 heavy machine guns; the B-29 didn't have what are considered "cannons" (usually 20 mm or more).
For the most part, defensive guns on bombers weren't all that useful; even with a fire-control computer aiding you, it's very hard to hit a (possibly maneuvering) moving plane from another moving plane. It would probably have been better to omit those heavy guns and turrets and to leave those gunners on the ground to save weight, lives, and resources.
The guns on a bomber were never really meant for engaging aircraft. They're meant to deter fighters from ever getting near the bomber. Not many pilots are willing to sit directly in the path of machine gun fire, even if it is not very accurate. German anti-aircraft figured this out as well. They switched to shooting mostly tracer rounds. You aren't going to hit anything in the first place, so you might as well just scare the crap out of them.
There were some WWII 'gunship' style modifications of planes, but that was not that common.
For a more modern comparison, consider that the Bradley fighting vehicle carries anti tank missiles. Sending a group of Bradleys directly against tanks would be suicidal. The Bradley has aluminum for armor. A well trained set of tank crews operating even WWII vintage vehicles would decimate them. Instead, the misiles are there to deter tanks from engaging them. It also provides the crew with an enormous psychological benefit. That benefit is they at least have the benefit of being able to respond to an enemy tank with a potentially lethal weapons system. Ironically of course the TOW missiles on the Bradley destroyed more Iraqi tanks the M1 tank ever did in the Gulf war. But that is because Iraqi tank crews either had no experience or had armored vehicles in horrible condition.
My father was the navigator in a B17. He said the Luftwaffe would try to sneak up behind the B17, to see if the tail gunner was watching. The tail gunner would let off a few rounds, even out of range, so the tracers would let the Luftwaffe pilot know he was watching. If not, well, another B17 down.
If that didn't work for the 109s, they'd do a head on attack. A head on attack made it very hard for the B17s to hit them, and the closing speed was so fast it would carry the 109s out of range quickly after the attack.
My father said that unlike the buffoonish German pilots portrayed in WW2 movies, the real ones were careful, professional, and deadly. You never wanted to let your guard down around them.
>The guns on a bomber were never really meant for engaging aircraft. They're meant to deter fighters from ever getting near the bomber. Not many pilots are willing to sit directly in the path of machine gun fire, even if it is not very accurate. German anti-aircraft figured this out as well. They switched to shooting mostly tracer rounds. You aren't going to hit anything in the first place, so you might as well just scare the crap out of them.
Never really meant? Some citations there would be nice.
US day bombers that were not protected by fighters often suffered heavy losses against the Luftwaffe. Which is why unescorted daylight bombing was suspended following the 25% casualty raid on Schweinfurt.
>They switched to shooting mostly tracer rounds.
..right. What I've read is that many units stopped using tracers altogether on pure fighters because their different ballistics at long range meant that they were not useful. The gas created when the base of the tracer burned diminished drag. (this has later been adopted for howitzer ammo, base bleed increases range by up to 30%)
= What I've read is that many units stopped using tracers altogether on pure fighters because their different ballistics at long range meant that they were not useful. =
You mean stopped using tracers against fighter aircraft, or stopped carrying them on fighters? The parent seems to be talking about ground AA gun crews using tracers -- presumably a lot of these would be firing at bombers?
Given that the Bradley was designed to fight Eastern Bloc forces on the plains of Germany (which comprises rolling terrain, closely spaced villages, streams, etc.) a vehicle that can be tucked behind cover and fire lethal anti-tank missiles isn't just decoration.
One of the most interesting cold war AFVs was an M113 chassis with a cherry picker and 15 TOW missiles on it. Armor is nice, but a hill is even nicer.
The problem is that the US army is still equipping itself superbly to fight the Eastern Bloc in 1985.
> One of the most interesting cold war AFVs was an M113 chassis with a cherry picker and 15 TOW missiles on it. Armor is nice, but a hill is even nicer.
= One of the most interesting cold war AFVs was an M113 chassis with a cherry picker and 15 TOW missiles on it. Armor is nice, but a hill is even nicer. =
Interesting, never heard of that one! Any links by any chance? I would be curious to look at pictures :)
(Edit: looks like another reply has a link!)
And IMO it makes perfect sense for the first priority to be always prepared for the toughest opponent: a TOW missile will destroy a pickup truck just fine, but it also forces the opponent to be much more careful with their tanks.
It's kind of an interesting story how the military didn't really want the Bradley in the first place but it was forced upon them by congress and they had to find a use for it.
I have a relative who was in the mechanized infantry back in the early 1990s. From what he was able to share with me, the Bradley was an interesting vehicle with a lot of cool stuff but if my life was on the line, I'd prefer to be in an M1 Abrams.
There is a pretty good movie "Pentagon Wars" about the development of the Bradley.[0] It's not entirely accurate, but even as complete fiction would be an enjoyable satire.
If my life were on the line I'd prefer not to be in combat, but if you're infantry, riding around in an Abrams isn't an option. It's like saying you'd prefer to be in a frigate.
It's a pretty cool vehicle, but with the $3MM price tag I'm not sure how suitable it is for an infantry carrier... But I agree, this type of vehicles are surely going to get more common.
The Isrealis have had mixed results from the Namer and Merkava (though the Merkava is an icon of pride, so this comment might draw some cheerleading). I think the basic idea of having extra passenger room in a MBT for flexibility in evolving situations is pretty sound, but these particular vehicles have proven pretty vulnerable in close in urban combat vs smart patient infantry.
Later on, they did exactly that: from about February onwards, Curtis LeMay had the guns and turrets stripped out of the force bombing Japan -- except for the tail position -- to save weight/increase range, speed, and bomb load. Operational consequences:
It would probably have been better to omit those heavy guns and turrets and to leave those gunners on the ground to save weight, lives, and resources
That is exactly what Freeman Dyson said of the Lancaster bomber.
Tho' no sooner had the belly turret been removed than the Luftwaffe invented upward-firing guns, they would slip into position directly under, matching speed and heading, then just let rip.
The Schräge Musik approach is also 'Keep It Simple' in contrast to the American over-complicate-it approach.
That term is also interesting as they considered jazz music to be 'queer'.
Ultimately though it was fuel that mattered. When the USA joined the war half way through it meant that Allied planes were on 100 octane petrol, meanwhile the Germans were using some glorified coal slurry and the Japanese were using some tree bark extract made by school kids.
> It would probably have been better to omit those heavy guns and turrets and to leave those gunners on the ground to save weight, lives, and resources.
Yep. The Mosquito was the safest (for the crew) bomber of the war, hugely more accurate and effective than the heavies. But heavies were the dogma of the politically influential in the air forces of Britain and the US, so much as battleships kept being considered the key asset long after they were actually irrelevant, thousands of young men were strapped into pointless flying coffins.
It was called flak and was quite effective. The Germans also deployed air to air missiles that were basically rockets with flak warheads on them. See the bomber guns had an effective range of 1000 yards or whatever so if you stood off 1200 yards in your ME-109 and launched rockets that blew up in 1200 yards that worked pretty well.
I've read a couple memoirs of WWII pilots, interesting stuff. I'm pretty sure they're all dead now, whats documented out there is all we'll ever have.
As for effectiveness, well, bomber aircraft losses were tremendous until the end of the war, yet they lost the war anyway. So its hard to say. If you can down 10% of the B-17 per bombing run against ball bearing factories, but still lose the war, was it effective or not? Or looking at the staggering economic and logistics costs of the air war, skipping the air war and focusing on shipping over tanks that don't suck might have ended the war in '44 or earlier, so maybe it was ineffective. Imagine if the winter battle of the bulge never happened because the war was already over by winter rather than lasting till spring. Or maybe no bombing would have meant more hardware would have meant the D-day invasion getting pushed back into the sea Dunkirk II style. Its an evenly balanced enough argument that academics will never lack for discussion topics.
I have a theory that even though the bombers didn't necessarily always hit what they were aiming at, the bombing campaign was important in tying up the Luftwaffe and degrading its capabilities through attrition, thereby hastening achieving air superiority, which provided a major advantage in the later ground war. I'm not sure that better tanks would have made as much difference; and, furthermore, I suspect that the US was able to absorb the costs of the air war without much difficulty, so it wasn't really siphoning resources away from things like tanks.
I'm not sure what to make of the Sherman tank. On the one hand, it was famously under-armored and under-gunned; on the other hand, it was fast, maneuverable, reliable, fuel efficient, cheap to produce, and perhaps easier to ship across the ocean than heavier German-style tanks would have been. So, in the final accounting, I'm not sure if it was really a bad tank or if its shortcomings were justified in the big picture.
I'm not any kind of WWII expert, so please fill me in on what I don't know.
The really crazy thing is just how much more massive the scale of the war on the eastern front was. Some of the Luftwaffe fighter aces racked up 100 or 200+ confirmed kills, primarily against the Soviets. Other pilots who flew close air support on the Eastern Front flew thousands of combat missions, destroying hundreds or thousands of tanks, artillery pieces, and other vehicles.
Can someone please explain how the gunner/computer established the range and speed of enemy aircraft? The article says "a gunner would focus a series of dots" but unless at least two gunners are focusing the same plane I have no idea how they calculated range and speed. Thanks.
I used to be a gunner on an M1A1, and although we had laser range finders, we also practiced with the old style optical sights that were installed alongside the main gun. How range finding works with optical sites is you usually have a series of marks in the viewfinder that you use to physically measure what you're aiming at, so if the tank/plane/whatever is between particular two pips (or whatever; edit iirc the M1 had two curved lines you would placer over the target) you know that it's about x meters away. The pips are calculated knowing the average length of the object, so this is, in practice, close enough.
The procedure is; measure the target, then use cross marks on the cross hairs to raise the gun tube to the appropriate level, manually guess lead and defilade, fire, on the way. It obviously takes practice to get good at. I found it curious that the US Army continued to teach/train/use this method, as well as land navigation with compass/mapp instead of gps. The idea is to not rely on technology entirely.
Edit: turns out I am describing stadiametric rangefinding:
I teach light infantry tactics to new lieutenants for the US Army. There's a couple reasons to use old-school methods over relying on your GPS:
* Using a compass and a map gives you a much better feel for terrain. One of the common problems with lieutenants is a disregard for advantages and disadvantages of specific terrain. I feel that this is by far the most important point. Understanding and visualizing terrain from a map is a hugely valuable skill that impacts most points of an operation, specifically route planning, where to place your machine guns, and where to attack the objective from.
* GPS can be jammed. This point was driven home hard by the novel Ghost Fleet. Ghost Fleet is a white paper turned into a novel (because no one would read a whitepaper) on what a future war with China would look like. I'm pretty sure Ghost Fleet is also the impetus for the Naval Academy re-adding celestial navigation to their classwork.
* GPS doesn't always work, or takes a while to get enough satellites to get a fix. You know what really sucks: taking fire and not knowing where you are.
* Batteries are heavy. Yes, tech is improving and you typically only need AA batteries. But soldier weight for light infantry is and continues to be a challenge.
In the early aughts I wrote a simulation for training infantry to call in artillery strikes. It relied on compasses and maps for exactly these reasons. Another point is that understanding what the automatic tools are doing for you makes you better at understanding the automatic tools (and why they're failing when they fail).
I seem to recall that the gunner on one of the more successful German tank crews during WW2 basically had the sights set for a specific distance and then eyeballed it from there.
What military doesn't teach navigation with a compass? I would also imagine that most, if not all, teach rangefinding to those who might need it; snipers/sharpshooters, gunners, etc.
My only military experience is from my compulsory service in the Finnish Defence Forces, where everyone does have to learn how to read maps and use a compass (we never used gps/other equivalent). I was in signals myself, so I didn't have any training for rangefinding.
In WWII we saw the introduction of practical optical coincidence rangefinding, starting with naval guns and quickly moving to direct-fire artillery, tank guns, and AA applications. One gunner, but binocular vision with the aiming mechanism using angle of incidence from each eye input to calculate current range.
I don't know about the B-29 system in particular, but gyroscopic gunsights used on most WW2 fighters were fairly straightforward. First, you set a selector on the sight to the wingspan of your target (usually there would be presets for common enemy aircraft). Then you twist a knob (typically on the throttle) that adjusts a ring in the sight until it matches the size of the target - this establishes the range. Finally a gyroscope provides input on how your aircraft is moving, and since you're typically maneuvering to follow your target this is an approximation of the target's movement.
There's a lot of approximation involved, but generally it's good enough to hit an airplane sized target, especially on US fighters where you typically have 4-8 machine guns spitting out 50+ bullets per second in a shotgun like pattern.
I was quite surprised to learn recently how the B-29 was (A) about as expensive a project as the atomic bomb and (B) almost a complete failure (until the firebombing of Japan) due to no one knowing about the jet stream.
I believe there was also the prospect that if the B-29 hadn't been available the atomic bombs would have to been dropped from the British Lancaster - which was the only other bomber capable of carrying them at the time.
Doesn't (A) count the cost of producing all 3,970 airplanes, not just the R&D cost? Seems a bit misleading to compare that to an R&D program that produced one test device and two bombs.
Out of curiosity (and possibly a dumb question), what is the main constraint preventing modern (subsonic) bombers from carrying CIWS-type defense system against missiles? Is it size, weight, recoil, aerodynamics, or special radar requirements? The initial push behind removing gun systems appears to have been development of AA missiles and increased reliance on fighter escorts. Yet modern CIWS on sea vessels have become so effective against missiles that they significantly upped the cost and requirements of anti-ship warfare, to the point that a single missile fired at a ship is not expected to be successful. Given advanced enough CIWS (using directed energy in near future?) one basically doesn't need stealth or other fancy/expensive/less reliable features.
I'm just guessing here, but I'm going to bet that defensive ECM is probably deemed better effective per pound that CWIS.
It's worth noting here that CWIS' effectiveness hasn't really been proven. But what is certain is that it's theoretical effectiveness is being questioned as missiles get faster. The original 20mm CWIS had a pretty limited range. The Europeans went to 30mm with Goalkeeper, and now both are set to be replaced with either directed energy weapons (faster tracking, better accuracy) or systems like SeaRAM, which can engage further by switching to point defense missiles instead of guns.
I can see how directed energy weapons could be attractive to aircraft once the power density issues are solved, but right now they're simply too heavy.
How did they do this without transistors? The only thing I can find is this diagram here which looks like a small box: http://www.twinbeech.com/images/TURRETS/cfc/CFC%20computer19... which is smaller than a vacuum tube. I'd assume you'd need vector calculus to calculate the path of a bullet?
The first thing to keep in mind is that these are not general purpose machines. They only do one thing, which is estimate the trajectory of a particular type of bullet, given several inputs.
This lets the designer do a lot of precalculation, so they might use a series of cams that approximate known curves or differentials some known ratio.
Useful google terms are things like "mechanical fire control computer" or "mechanical tide predictor".
Check out "Old Brass Brains" it might give you an idea of how to approach this kind of problem mechanically; or at least how sophisticated a mechanical approach can be.
I had no idea that fire control computers in airplanes were so sophisticated in the 1940s. Truly amazing! I don't know what I thought, but I guess I assumed that air battles back then relied primarily on line-of-sight and tracers to compensate.
It's amazing how effective automation can completely transform an activity and elevate it to a new plane of effectiveness. I'll channel Andreessen and say: technology is eating the world.
"It was a plane so advanced, we wrote in June 1945 about how one crew fought off 79 fighter planes, downing 7 of them, during a bombing run on Kyushu, Japan. Its weapons platform was so dominant that fighter escorts were no longer strictly necessary—as Major General Curtis LeMay put it simply: "These big boys can take care of themselves."
Remember that the war was basically over at that point, and they were fighting against an enemy starved of resources and experienced manpower, particularly pilots (cf. kamikaze tactics).
The "79 fighter planes" claim doesn't pass the sniff test to me either. Remember that two months after this, the Japanese didn't even bother sending fighters to even try to intercept the planes that bombed Hiroshima (for example).
I'm not saying that the claim is definitely false, but I wouldn't take anything written in the press during the actual war at face value.
I always figured the Japanese assumed the plane in the case of Hiroshima was a reconnaissance plane gathered ground photographs and checking on the weather. As you correctly noted, they didn't have many resources. I'd figure a lone reconnaissance plane would rank pretty low on the list of targets they were trying to intercept.
Even a lone bomber plane would not have been that much of a threat at this point. Bomb the weapon factories, the war is over. If they had known what was coming they would have deployed a lot more and evacuated the civilians.
That's a common interpretation of the Japanese reaction. I admit to a limited amount of knowledge on this subject but I have never seen anything that contradicts that view.
The "79 fighter planes" claim doesn't pass the sniff test to me either. Remember that two months after this, the Japanese didn't even bother sending fighters to even try to intercept the planes that bombed Hiroshima (for example).
The first proposition is a reasonable explanation for the second. If you're not willing to lose 79 fighters, then don't engage a B-29.
There's a recorded instance of a B29 shooting down 14 fighters over Tokyo (it was also rammed by two fighters and still made it home). There are also instances of B29s downing MiGs over Korea.
The late model B17s were pretty effective too. An old Strategy & Tactics magazine quoted stats for two different air forces (recall it was the "US Army Air Corps" and "Air Forces" were simply an organizational unit) operating out of Britain over a two year period in WWII, one was bombers and the other fighters. Both shot down roughtly the same number of planes -- but the bombers used 100x as much ammunition. (Sorry, this is a 1970s print publication, no link, just my memory.)
Also recall that the Japanese lost almost all their trained pilots early in the war, so the B29 was using a far superior weapon system against very inexperienced pilots.
Kill claims are notoriously overestimated during this period, frequently by ratios of 5:1 or more. The only reliable way to estimate kills is to look at enemy records and see how many aircraft were recorded as lost during a given period.
Take a look at some of the entries here; April 17th stands out.
"the 91st and 306th Bomb Groups claimed 63 German fighters destroyed, plus 15 probable and 17 damaged. Only two were confirmed destroyed, with nine damaged."
Few different points made in that episode, some relevant to this discussion some not and some I'm not remembering.
1) The B-29s had god-awful bombing accuracy in their original mission (high altitude level bombing) because of the as-of-yet-undiscovered jet stream over Japan. So when they flew too high and fast to be intercepted, they were basically useless when it came to doing damage.
2) This was already in the Kamikaze era of the war, and many B-29s were lost to that.
Anyway, I'm not going to rewatch the whole 45-minute long episode again. I found some stats that listed a total of 74 lost from fighters, but I'm hesitant to post because I can't dig up the original source (it 404s now). Will if you so desire. The number lost due to weather, mechanical failure, etc., dwarf the number lost to fighters by a huge factor but it does make the original quote here sound like some amount of propaganda bullshit.
https://en.wikipedia.org/wiki/Rangekeeper has a decent summary of the development of this tech.