Head Wounds and Steel Helmets | Hacker News Reader

Head Wounds and Steel Helmets

historicalfirearms.info

35 pointssmacktoward21 comments

It reminded me of this funny "paradox" : https://www.youtube.com/watch?v=1IQE0uZUMys TLDW : In WW1, after being issued helmets, the number of head injuries for soldiers rose significantly.

It's like the old story about when airbags (or was it seatbelts?) became mandatory, serious injuries from car crashes became much more common - because many more people were surviving serious crashes and being counted as injured, not killed.

These both seem illogically logical, kind of like the other story about an engineer who figured out where to armor aircraft by looking at the ones that came back -- he armored the places that were never shot up.

More info:

>Blackett's team made the logical recommendation that the armour be placed in the areas which were completely untouched by damage in the bombers which returned. They reasoned that the survey was biased, since it only included aircraft that returned to Britain. The areas untouched in returning aircraft were probably vital areas, which, if hit, would result in the loss of the aircraft.

https://en.wikipedia.org/wiki/Operations_research#Second_Wor...

That whole article section is delicious. It has many examples of clear-headed people looking at a situation, figuring out a logical approach, and demonstrating that it worked well.

The specific story of armoring an aircraft would be best completed by "...and the loss rate per mission was cut from x% to y% on the new planes". Unfortunately, that's one of the few examples that the section doesn't explicitly say demonstrated improvement.

I've heard it many times, and it's great, but I think it must not be true. Planes had hardly any armor at all and all I've ever seen was put in very logical places. Protect the engines, fuel, pilot, and other crew.

It's not like they welded a piece of steel into a random place on the hull because they'd never seen it get hit before.

Whilst it may not have been Blackett or his team doing the research, research in this area does seem to have been done(1), and there are books and papers written about it(2). 1- https://www.lesswrong.com/posts/kyZgEKzZZtJQTCSG2/examine-yo... 2 - https://people.ucsc.edu/~msmangel/Wald.pdf

The point is that it would not be a random place.

The complete absence of armor in the Mitsubishi Zero is often cited as one of the reasons why it became outclassed by American fighters later in WWII.

Also it's not like they had no clue which parts of an aircraft were important. The less-snappy but likely more accurate story is they looked closely at the parts without bullet holes in them to see what important components in those parts could use some more shielding.

Ironically for bombers they probably would have achieved better results by stripping off most of the armor and all the defensive machine guns (and gunners). The weight reduction would have allowed them to fly higher and faster, making them less likely to get hit in the first place.

They're never going to be able to fly faster than the fighters trying to intercept them though and flying higher makes them less effective at hitting their targets requiring more missions and more collateral damage so I'm not sure your plan works out with those factored in.

Flying faster exposes you to those interceptors for less time and makes it harder for them to reach you before they run out of fuel. As for accuracy, they already had trouble reliably hitting any target smaller than an entire city so I don’t think it would make much difference for that to be a bit worse. But good luck convincing the folks in charge to give up on the idea of “precision” bombing....

My plan worked fine in practice. Look at the lower loss rates achieved by Mosquitos and similar fast bombers. At that time, fighters had limited endurance at high speed and were barely faster than bombers, so a small increase in bomber speed could make interception effectively impossible. And at higher altitudes the smaller fighters had trouble even turning due to high wing loading.

Bombing accuracy was a moot point. None of them were able to reliably hit a target smaller than a city regardless of speed or altitude.

Bombing accuracy in daylight could be better than that...

http://ww2today.com/9th-october-1943-the-marienburg-focke-wu...

Probably both but like anything else I think you could make the data look however your agenda wants if you monkey with the definitions of terms. A seat-belt is a great way to wind up seriously injured when you otherwise would have died and boring old frontal airbags tend to make serious injuries less severe and minor injuries more severe.

The perfect example why looking at only one metric is sure way to disaster. Should be part if every lecture covering KPIs, ideally more than once!

"The majority of the head wounds were believed to have been caused by shell and grenade fragments."

So two possibilities might be that bullet wounds to the head would be more often fatal or that most deaths and wounds come from artillery and grenades.

I think that the later is the case and that a soldier's probability of survival is mostly a combination of skill in maintaining cover and luck.

This is similar to the story about planes coming back with holes during WWII. They focused on adding armor on those spots but the number of planes that came back home didn't increase. It turns out that the planes with the holes were the ones hit in non vital spots. They should have up-armored everywhere BUT those spots.

It's a similar situation here. The helmet prevent death but increase the amount of injuries. Removing the helmets and adding more body armors would be problematic.

Edit: Wrote this out of memory but here's a source if you want to read more. https://medium.com/@penguinpress/an-excerpt-from-how-not-to-...

this reminds me of ~~ https://www.napoleon.org/en/history-of-the-two-empires/objec...

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I got that too, seems to be working at https://www.historicalfirearms.info/post/185618493489/head-w...

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