D-Day: How a British Oceanographer's Invention Decided Normandy's Fate | Hacker News Reader

D-Day: How a British Oceanographer's Invention Decided Normandy's Fate

inverse.com

115 pointsnikse44 comments

Now that's an exaggerated title. The headline on the page has "74 Years Ago, a Brilliant Invention Decided When D-Day Would Occur" not "Decided Normandy's Fate". I was under the impression that hundreds of thousands of people fought in that battle? Did they not influence the outcome somewhat?

Maybe they meant "Decided Normandy's Date"? #fatfingers

Planting dates in the Normandy, at this rate of climate change, will be a matter of at least... decades.

Actually, effects of climate change are not that bad even when looked st the extreme 100yr scale.

This is the best explanation! Actually if the editor posted this article on her phone, it might even be auto-correct? What would that say about how often such an editor posts clickbait, that she uses the word "fate" more than the word "date"?

That was the RAF meteorologist, James Stagg, who persuaded Monty and Eisenhower to move the date from the 5th to the 6th. :)

Famously if they had not gone on the 6th the next tide window would have seen the worst storms in years.

The Met Office's page: https://www.metoffice.gov.uk/news/in-depth/d-day-70th-annive...

There is an excellent write-up of this at https://medium.com/@garius/the-weatherman-the-man-who-decide...

Thank you for linking that. I'd not known that Krick was quite so alternative in his beliefs!

And the forecast was verified with a last-minute weather report from the lighthouse at Blacksod, Ireland, thanks to a 1921 agreement:

https://m.independent.ie/irish-news/how-blacksod-lighthouse-...

"An hour later, the same caller, 'a lady with an English accent', asked for the latest weather observations."

https://www.flickr.com/photos/openplaques/13198792295/

It should be "contributed one of many factors that decided when D-Day would occur". It's annoying that people always want to find a hero who did it all alone.

fwiw i actually posted it with the articles title and it was updated without my knowledge

The HN title is faithful to the actual HTML title tag, including the word "Fate". The headline on the page differs.

This sort of mismatch seems fairly common. It's probably some sort of SEO scheme...

I wonder to what extent they A/B test these titles, then pick the one getting the most traction.

One could argue that what really decided Normandy's fate, and the fate of all of occupied France, was Operation Bagration, the real gut-punch that smashed the Wehrmacht and broke them, hundreds of miles to the east.

The scale and savagery of war on the eastern front is so mind boggingly incomprehensible, and relatively unknown for an English-speaking audience. If you have not, I highly recommend Dan Carlin's Ghosts of the Ostfront series of podcasts, to get even a sense of the insanity.

The western front was, in totality, almost a sideshow in comparison to the titanic, inhuman struggle raging from Black to Baltic seas.

The same goes for WWI. I'm not downplaying the horrors and scale of the Marne, Somme and Aisne, but the siege of Przemyśl, the battle of Lemberg were comparable yet not nearly as infamous.

When we think of WWI we think of the trenches in Belgium and northern France. Sure, Belgium was hit pretty hard (120,000 casualties, about 1,7% of population) but compare that to Serbia: 1 million casualties, a staggering 25% of population... and most people don't even realize that Serbia was affected by the war in the first place.

The austro-hungarian war, and its futility is also incredible - I don't have the title now, but I've read something outlining their mobilization plan up to Tannenberg. The whole Balkans region that started the conflagration is so confusing and bloody...

> mind boggingly incomprehensible

Absolutely agree.

I strongly recommend this interactive illustration of the casualties of ww2, which really drives home the scale of this catastrophe.

[1] http://www.fallen.io/ww2/

1.5 million troops (not even counting civilians) died at the siege of Leningrad. One million at the battle of Stalingrad.

To most people, "Kursk" is the name of a submarine but it is also the biggest tanks battle of the history of mankind, and the point where USSR made the tide turn in favor of the allies. This battle alone saw more death than the campaign of Normandy.

It is funny how these things work. We tend to put an heroic filter on the Allies' operation on the D-Day and trivialize the French defense in 1940 as a buffoonery despite both having a similar death toll. And we ignore the big battles that bled to death the USSR and that actually won the war.

One can't understand stalinism and the Russian brand of nationalism without knowing that history.

> I highly recommend Dan Carlin's Ghosts of the Ostfront series of podcasts, to get even a sense of the insanity.

Just don't take any factual claims Carlin makes as fact. He is a storyteller, not a historian. He editorializes his stories a lot.

> The scale and savagery of war on the eastern front is so mind boggingly incomprehensible

Logistic and thought behind the D-Day is also mind-boggingly incomprehensible.

Can we stop glorifying Stalin's butchery, please? Yes, they've managed to lose 10 times more soldiers than British and US combined and suffered enormous loss of civilian lives.

But you know why? Because Communist leaders had no respect for human lives.

They omitted the lede - the original plan for that day was disrupted by very severe sea and weather conditions; Eisenhower decided to risk the landing with a good chance of better weather by then, but would he have done so with less certainty about the tidal conditions as well? It was a close decision, so perhaps not, in which case there wouldn't have been a battle that day at all.

The timing of d-day was important to the outcome because it allowed the allies to benefit from some really good luck. The German's were caught off guard, and were slow to respond. This reaction was hardly assured and may have been different if D-day had gone ahead later. It is interesting how some quite modest efforts contributed to this. For example, superior weather forcasting allowed the allies to exploit a weather window that the German's did not know about. It is interesting to ponder how things may have been different with less accurate data. And it demonstrates how vitally important detailed planning was.

Its an impressive example of human knowledge and ingenuity, although the article does get a little overly dramatic with it.

Perhaps that's a side effect of how crowded that period of history is with these kinds of things. It's hard to look at any date range between 1939-1945 and not find at least one or two accomplishments which seem almost impossible for the time and technology.

I'm watching WWII in color and when they got to late 1944 and the rockets, I was pretty floored. I thought, "holy crap that was close. Imagine what could have been if they had mature rocketry even just five years earlier..."

That is a really great series that has a lot of depth.

Not much. The V-2's guidance system was primitive, and so where it hit was fairly random. Force has to be concentrated on targets of military value to be effective.

Consider the vastly more bombs dropped on Germany day and night, far more than V-2's ever could have dropped. Aside from destroying the oil infrastructure, it's hard to see the military value of destroying city after city, and that bombing was much more precise than the V-2s.

For rockets to be effective, one needs either precision guidance or a nuclear warhead.

I was thinking more about how rocketry leads to jet planes. But also, my understanding was that bombs were awfully inaccurate. Not that pre-gps long range missiles are any better. My understanding was that the ramjet rockets were pretty terrifying too and did hit cities often.

> Not that pre-gps long range missiles are any better.

They were much, much better.

EDIT: It appears the V2 in testing had a 4.5km CEP, while he minuteman III has a 200 m CEP.

> rocketry leads to jet planes

They were developed independently of each other.

> did hit cities often

Randomly hitting a city has a very small chance of hitting anything with military value.

> terrifying

Sure, but it turns out that terrifying citizens tends to harden their resolve to fight on, rather than surrendering. On both sides.

The real "secret weapon" of the Allies was radar. Radar controlled anti-aircraft guns, and radar controlled artillery acted as a "force multiplier" by putting the munitions on the target. Radar also crippled the U-boot fleet, enabled the Allies to respond effectively to attacks, and enabled seeing through the weather.

Necessity is the mother of invention.

Here is a summary.

He built an analog computer that could predict tide levels. They wanted extreme tides so that at low tide the navy could map out the traps the Nazis left, and at high tide they could land lots of troops. It turned out that acceptable tide conditions happened on June 5, 6, and 7.

The actual invasion happened on June 6.

They also sent x subs mini 2/3 man subs to drop divers to take samples of the beach surfaces

They also collected as many postcards, maps, personal photos as they could, to build up photomosiac maps and models of the beaches.

Anthony Beevor talks about a lot of this stuff, as does Carlo D'Este and others. Great reads.

(my mum was an art college student at the time, and amongst other things she was drawing maps. My Aunt was doing technical drawings for the mulberry harbours. Everyone pitched in)

Ok fine. The title is somewhat exaggerated.

Look at this story as another in a series of extreme efforts in 1943/1944 leading up to D-Day, the absence of which could have resulted in a different outcome. The portable Mulberry harbors. The Higgins boat. Operation Fortitude's ghost army. Juan Pujol's network of fictitious German agents. And even with all of those efforts, had Hitler decided to move Von Schweppenburg's panzers, D-Day would likely have failed.

So yeah, again, the title is a bit breathless, however it's not a stretch to say that much like at Incheon getting the tidal flows wrong would have significantly altered history.

The Allies had total air superiority, and the panzers would have had a very hard time against that.

TL;DR: Invest in blue-sky research since you might never know when you need it.

What decided Normandy's fate was germany's lack of a navy and their air force and soldiers being locked down on the eastern front.

Germany had like 5K soldiers on the beach with no air and no naval support against the combined might of the US and UK.

D-Day was 200K US/UK soldiers + US/UK navy + US/UK air force vs 5K germany soldiers.

It was such a rout and easy victory that most of our casualties on that day was friendly fire and accidental drowning rather than germany bullets.

D-Day is so overplayed in our media. The real fighting was in the east.

The typical number for German combatants is closer to 50k, so I'm curious what your source is for 5k.

He also said "real fighting was in the east", so you can guess the source.

Edit: also the claim "most of our casualties on that day was friendly fire and accidental drowning" is pretty ridiculous.

> He also said "real fighting was in the east", so you can guess the source.

It's called stats.

https://en.wikipedia.org/wiki/German_casualties_in_World_War...

https://en.wikipedia.org/wiki/Eastern_Front_(World_War_II)

The vast majority of the german military and casualties, were in the eastern front.

> Edit: also the claim "most of our casualties on that day was friendly fire and accidental drowning" is pretty ridiculous.

It's pretty much common sense. Considering the low number of german troops, the poor coordination on our side and of course the odds of accidents and friendly fire incidents. It's pretty much a statistical certainty that most of the deaths on D-Day were accidents and friendly fire. But lets throw out common sense and statistics out the window.

The germans had no navy. They had no air force. They had nothing. Against the might of the US and British power on D-Day. But we can pretend that the germans managed a 2 to 1 casualty victory. Or I'm sure that's what your "sources" will try to convince us.

That's for the overall invasion that spanned more than a month ( AKA germans defending half of france ). I'm talking about D-Day ( 1 day ) incident where hardly any fighting took place.

It was impossible for 50K german soldiers to defend the beaches because germany had no air force and no navy to protect them. The allied navy and air force pretty much cleared out the beaches and the germans had moved most of their forces to the east. Only a skeletal force of a few thousand were left to defend the beaches.

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