I’d still like to see one of the repainted collector-termed “shipboard grey” helmets weighed. At least we know now that the helmet that started the thread is not a Type 3.
I’d still like to see one of the repainted collector-termed “shipboard grey” helmets weighed. At least we know now that the helmet that started the thread is not a Type 3.
we are talking about heavier weight than 1400g for a type 3 and according to the size obviously..if my helmet of 1570g is not a type 3 what is it considering the rarity and that it is on photos before the war? if someone can say..thank you very much
You definitely did not measure thickness at the right place. 1570 grams is indeed too heavy to be an official version of a Model 3, but it is too light for it to be out of a steel sheet 2.3 mm thick. A Model 2 helmet is 1mm thick, so if made of 2.3mm steel throughout, it should weigh 2.3 times more than a Model 2, which would make it nearly 2.8 kgs. The total weight of 1570 indicates the average thickness of the steel to be only about 1.3 mm instead of 2,3 mm.
You definitely measured at the rim, and in the dome it would be much thinner.
The logical possibilities are one of the following
1. Prototype of the Type 3 (if thickness is 1.2 mm at the dome)
2. Prototype of a bullet-proof version (navy's equivalent of the army's type 98)
3. Fake
But no one seems to think they are fake, so two possibilities remain.
hello nick, after measuring in the small holes on the sides of the domes there is indeed 1.3mm!
That will be too thin as any attempt at bullet-proofing, so by default, it can only be a prototype or early version of a Model 3.
They obviously had not overcome yet the problem of thickness changes in pressing thicker steel and ended up with a product too thick and heavy at the rims. They must have had to reduce the flare at the rim and reduce overall height of the helmet to make the desired dome thickness compatible with overall and tolerable weight. The thin cloth liner must have been another sacrifice in order to reduce overall weight.
Once they were able to press steel into a product with more even steel thickness throughout, they would have been able to make the design identical to a Model 2. That would explain the disappearance of this shape only seen in grey. Brown Model 3s are likely to be identical in appearance to Model 2s.
the kangis inscribed on the helmet and the number 47 anyone have an idea?
The Kanji means Rescue, but medical personnel would not have used that word.
Now that measurements revealed limitations of production techniques, we can create a fairly realistic hypothesis on how Model 3 development and production evolved.
Pressing out such deep-domed steel helmets cannot be done in one pressing process, but only in gradual steps through several huge machine presses lined up, each with a die that gradually deepens the dome. This helmet is the result of not being able to afford those gradual steps.
It is possible to use only one press and change pressing dies after a given number of runs, but switching dies involves a lot of down time before the next run can begin, so mass production is only possible when you have multiple press machines feeding directly into the next.
But in mid-1933, when the Model 3 began production, pressing machines would have been fully tied up in Type 90/Model 2 production. Under that circumstance, it would have been nearly impossible to install another full new line dedicated to the Model 3, so they probably compromised by only assigning a minimal number of press machines to the Model 3. Taking out the gradual in-between pressing steps would cause uneven thickness and rough surfaces as represented in the helmet in question.
Ideally they should have first finished the run of Model 2s and switched those machines to the Model 3s, which would have been able to produce a much higher quality helmet, but with the NLF already actively involved in the conflict, they probably judged they could not afford the delay and launched the Model 3 with minimal investment (substandard quality).
Once the supply of Model 2s stabilized, they would have been able to switch more machines to Model 3 production. Then they no longer would have needed to reduce flares to reduce weight.
I contacted the owner and he replied today that the weight is "1196 gram". This seems to confirm that the Model 2s can be identified by weight as indicated in prior posts.by Kiipu
Another thing worth looking at is whether any of your helmets are marked with a 3, ㊂, 三 in paint on the inside rim.
If Models 3s are so well hidden that even longtime collectors cannot locate a single one, that would also have been a nightmare for quartermasters to sort out. There had to be an easy way to sort identical-looking items that shouldn't be mixed up. Normally they did that with painted markings.
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