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Aug. 15, 2023 - Skeptoid
17:55
Skeptoid #897: The Secret of the Norden Bombsight

Pop culture tells us the famous Norden bombsight from World War II was actually terribly inaccurate. Was it? Learn about your ad choices: dovetail.prx.org/ad-choices

Transcriber: nvidia/parakeet-tdt-0.6b-v2, sat-12l-sm, and large-v3-turbo
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The Norden Bomb Site Myth 00:05:37
If you've heard anything about the Norden bomb site, the device used by Allied bombardiers in World War II to help drop their bombs so precisely, it's either that it was incredibly accurate so that it had to be kept a secret, or that it was actually terrible and not accurate at all.
There is a dominant narrative here, but is it the correct one?
The Norden bomb site is coming up next on Skeptoid.
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What you didn't know about the Norden bombsite.
Ah, the famous Norden bombsite.
We gasp whenever we see one in the World War II wing of an aerospace museum.
We read the placard telling us that it was so accurate it had to be highly classified.
And then we go home and see something about it on the internet, and we're told the exact opposite.
That it was actually so bad that the real reason it was classified was so the Germans wouldn't find out how terrible our capabilities are.
Which story is true?
If either one is granted, not everyone knows about the Norden bombsite, and a lot of you have probably never heard of it before.
It was supposed to be this incredibly accurate bomb site that won World War II for the Allies, allowing our high-altitude B-17s to destroy the Nazi factories with unprecedented precision.
But for those of you who have heard of it, the thing you probably think you know is that the Norden bombsite was actually terribly inaccurate, like missing its targets by half a kilometer.
That's the dirty little secret about this famous secret weapon, that it was virtually useless.
You may have seen this revealed on any number of history channel shows.
You may have heard Malcolm Gladwell reveal it in his TED Talk, and YouTube is bursting at the seams with generic conspiracy videos making the same claim.
Whole books have been written showing that the Norden was worthless, and that that was the secret Allied intelligence had to protect.
Well, guess what?
That's all pop culture misinformation.
It's sizzle and it sells, and so it's the version you'll probably continue to hear in most any programming on the topic.
But not here on Skeptoid, where our job is to separate fact from fiction, to tease out misinformation from pop culture.
So sit back, enjoy, and let Skeptoid pull back the curtains.
So the basic problem of high-altitude bombing is a pretty obvious one.
You're in a certain plane flying a certain speed at a certain altitude with certain wind conditions, dropping bombs that are certain sizes and shapes and weights.
And you need a formula that can combine all of these variables and tell you exactly where the plane needs to be and exactly when to drop the bombs.
We'd learned enough during World War I to know that this was a problem we really needed to figure out.
World War II was to be a war of industry.
And bombing the enemy's industry was a primary strategy.
Carl Norden was a Dutch-Swiss immigrant who consulted for the U.S. military on gyroscopically stabilized systems and was brought in in 1923 to find a way to stabilize the current bomb sites.
From then on, the Norden Company was the military's go-to provider for this all-important task, to the point that $1.1 billion was spent developing it.
As American engineers worked on new bomb sites, German engineers did the same.
Both knew the problems very well, and both knew the same basic way to solve them.
Gyroscopically stabilized bomb sites communicating with gyroscopically stabilized autopilot systems for the aircraft.
The goal for both sides was to develop a bomb site which the bombardier could calibrate, then enter in all of these variables, then spot the bombing target in a telescopic site, and if all went well, the plane would stay on target, close in, and automatically release the bombs at exactly the right time and place.
The Norden bomb site is often described as the first bomb site that put all these pieces together and worked successfully.
Engineering an Adventure Together 00:03:08
But that's not really fair.
Norden was one company in the United States developing such systems through the 1930s, but Sperry was also doing the same.
And in Germany, the Carl Zeiss company, yes, the same Carl Zeiss that makes your camera lens, was also building similar systems.
And really, none of these companies were working in isolation.
In the United States, the government ordered Sperry and Norden to work together to build their bomb sites to work with the Honeywell autopilot systems.
This is an oversimplification of what was a decade-long arms race between these competing companies, but it's how the situation ultimately worked out.
Plenty of German engineers worked at all three companies, and at least one of them, a Hermann Lang at Norden, gave the blueprints of the Norden devices to the German military in 1938, and was then promptly arrested for espionage once he returned to the United States.
But the plans had been delivered.
So the Germans, with full knowledge of the Norden bombsite and a working prototype based on the plans provided by Lange, still proceeded with their own existing device, finding nothing in the Norden they hadn't already figured out on their own.
Lots of smart people, all working on the same problem, which was well understood, had all come up with basically the same solution.
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Why Bombs Missed Targets 00:06:36
The Norden Mark 15, the Sperry S1, and the Zeiss-Lotvenrohr 7 bomb sites all had the same basic configuration.
They were what we call tachometric bombsites, built on gyroscopically stabilized chassis mounted on gimbals inside the aircraft, so that as the aircraft moved around, the bombardier could maintain a perfect sighting on the target.
Atop that base was the telescopic sight and the controls for adjusting everything.
Where the Norden differed from the other two was in its complexity, which was really a curse in more ways than an advantage.
First of all, while the other two were single self-contained unit, the Norden was in two parts, the lower gyroscope, which remained mounted in the aircraft, and the upper sighting assembly, which was securely removed from the aircraft when not in use.
The DC motors driving its gyroscopes threw a lot of carbon dust from the brushes, which got into the bearings and required regular cleaning and maintenance.
It had 61 ball bearings, which required lubrication and cleaning.
Operation of the Norden was also more difficult than with the other two.
The first step of the bomb run was to write the unit to get it perfectly level, a process requiring the use of finicky spirit levels that required 8 minutes and 30 seconds to complete, which is a chunk of time out of a bomb run.
Then many settings had to be entered into the device based on the speed, altitude, the trail, how much farther behind the aircraft would the bombs hit the ground based on their aerodynamic qualities, weather conditions, and more, all using dials located only on the right side of the unit, while Sperry and Zeiss bombardiers could use both hands.
Finally, the bombardier would locate the target and work with the pilot to get the plane onto the planned approach, before connecting the bomb site electronically to the aircraft's autopilot to stay precisely on the final bombing run.
There was a lot working against all three bomb sites.
First of all, planes move around a lot.
They bounce and vibrate, particularly when they're in combat and potentially flying through flak or dodging it.
At the instant the bombs release, no plane would ever be exactly level, and every plane would always impart some unwanted movement to the bombs.
Pilots never wanted to make the bomb run at a level altitude, as changing altitude was a crucial maneuver to defeat the flak gunners.
Falling bombs would first pass through massive turbulence caused by the bomber fleet, and then through differing zones of wind.
Weather often cooperated and often did not.
And since everything depended upon visual sighting of the target, frequently the whole operation was based on bombardiers' best guesses.
Air temperature and humidity were also variables taken into account by the tables used by the bombardiers, but the actual conditions rarely exactly matched the predicted or assumed conditions.
The number of inherent problems that were outside the control of the bombsite went on and on.
So the stories you might hear about how the Norden performed well in testing and controlled demonstrations, but widely missed its targets during actual combat, are true.
But that's true for all bombsites.
There's only so much dropping the bomb at the right time and place can do.
So much influences everything that happens next.
But so far as what the bomb sites could do, they did it very well.
The Norden did as good a job as was possible, as did the Sperry and Zeiss units.
In fact, none of these designs has ever been substantially improved upon in all the decades since.
Only incremental improvements such as better electronic servos and controls.
In fact, the Norden continued to be used as the United States' primary bombsite through the Vietnam War, until they were finally replaced by new generation systems such as the radar-guided Sperry-Rammed K3A bombing navigation system.
These newer systems were better integrated into modern aircraft and made the bombardiers' job easier, but in point of fact, could not release their bombs any more accurately than did the Norden.
Again, because the problems are outside of the bomb site's control.
These problems remain today and are why we now use guided munitions that correct their own course as they fall.
The Norden bombsite truly was as good as a bombsite could be, and the modern stories you hear that it was actually terrible are false.
So why is it the Norden that's said to be the best bombsite and not the Sperry?
Why did the Sperry, with its simpler design, better electronic servos, and ease of use, not become the United States' primary bombsite?
Well, it turns out this had to do with other factors.
First, Sperry had already been an international company prior to World War II with facilities in both Japan and Germany.
This was considered a security risk.
Second, two of Sperry's key personnel, their military marketing representative, Fred Voes, and their main advocate in the military, Major General Frank Andrews, were both killed early in the war.
Third, Norden really played up the classified nature of their device, emphasizing its theatrical secure removal from planes between uses and working all this for its marketing value, while Sperry never even acknowledged that they made bombsites.
Finally, Norden, with its original 1923 contract, simply had the inside track.
And so, seek not to place blame where it is undue, simply for sizzle and clicks.
Top engineers in their field actually do tend to know what they're doing, as a general rule, even if the job they're tasked with is a nearly impossible one.
The Norden bombsite was as good as it reasonably could have been, no matter what TED Talks and YouTube have to sell you.
In the ad-free and extended premium feed, we continue with why neither the Germans nor the Japanese put nearly as much effort into their bombsites in World War II and why they didn't have to.
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