Related thread provided by tetsubo here Another photo of the Japanese Army M1918 helmet
By the way, having now studied the material variances in steel caused by the wartime resource limitations, I now feel that the helmets marked as class 2 weapons may possibly be referring to use of a less bullet-proof alloy in helmet production. Just a theory at this stage, but shouldn't be too hard to check whether it's true by checking steel related archive files.
Helmet Repaints
Contrary to what owners of weird colored IJA helmets like to imagine, IJA helmets were not repainted by individual soldiers in the field, but at field depots (野戦貨物廠 or 野戦被服廠), where other items like uniforms and boots were also repaired.
The Special Paint
These field depots stocked paint specifically developed for helmet refinishing, which came in two can sizes of 25 kgs or 5 kgs, the former being the standard size. 240 grams of this paint could refinish 10 helmets, so even the small can was enough for 200 helmets.
This matte brown paint consisted of highly acid-resistant pigment suspended in lacquer of an artificial resin and was specially developed for refinishing of helmets to meet the following test criteria.
1. After 6 hours of immersion in a water solution of 10% acetic acid and 5% salt, scratching with fingernails should not cause any delamination.
2. 50 strokes with zero grade sandpaper wrapped on a fingertip should not produce any delamination.
3. Must dry completely within 6 hours after brush application.
4. When applied to thin steel, the paint surface should show no cracks or delamination when bent outward by thumb pressure to an angle of 90 degrees.
5. The tone of brown and degree of matte finish to match control samples.
These tests were to be performed after 1 week of normal drying, according to Army specifications issued on 22nd October 1939.
Though it had to be dry to the touch within 6 hours, the paint surface continued to harden for a full week of natural drying. So it was recommended to let it sit for a week before reissuing the helmet.
Cans containing this paint were required to have labels indicating content as "helmet refinishing paint", as this paint could not be used on other gear, like mess kits and water bottles, which required heat resistant paint.
Field Depot Helmet Reconditioning Process
Refinishing of helmets at the field depot normally involved rinsing off dirt and grime with water, soap and brush, followed by sandpapering (zero grade coarseness) if necessary.
When dry, paint could be applied by brush. However, it was recommended to allow the helmet to bake in the sun for a while, before the paint, to achieve best paint adhesion.
The inside of the shell was only repainted when excessive rusting or paint loss was apparent.
The helmets were then to dry after painting in a well ventilated, dust free place for about 3 hours before further handling.
The liners were prone to develop mold through sweat, so frequent brushing and wiping was recommended. However, if hardened and brittle, they were to be replaced, taking care not to break the split pins holding them in place.
Chin straps were only replaced, if damaged or in fragile condition.
Last edited by Nick Komiya; 09-09-2021 at 03:56 PM.
1937 December Prototypes of the Bulletproof Steel Helmet
I explained in the main text that by December of 1937 it came down to a comparison test in the field between two design alternatives for the bulletproof helmet for assaulting enemy positions like bunkers by combat engineers.
Those two prototypes were as shown below in design. The slightly German style prototype could be attached with a 2mm thick steel plate in front like the German M16 helmet of WW1. This helmet can be seen worn by an IJA combat engineer in this newsreel of IJA troops approaching Nanking in late 1937. The scene is at frame 5:08.
The Otsu Model with a separate front plate will later get officially adopted as the Type 98 Steel Kabuto (not Tetsubo like the Type 90).
Here's the Type 98 helmet's field-repair permissibility classification from the weapons list of 27th February 1942, showing only the front armour plate as off limits to the unit smith. It is listed among the assault and chemical weapons.
The only detailed spec description of the Type 98 helmet surviving is one prepared by the 26th Infantry Regiment in 1940, who had fought the Russians in the Nomonhan Incident of 1939, using the Type 98 in its border defense.
4. MATERIEL:
Nothing new in the way of materiel was seen. The infantry equipment was the same as in previous years, including neither helmets or gas masks.
American Military Attache Report: Grand Maneuvers of Japanese Imperial Army, dated 1919-11-24.
INFANTRY
About 30 steel helmets, per regiment, have been issued for instruction purposes.
American Military Attache Report: Visit to the 19th and 20th Divisions in Korea, dated 1920-06-23.
3. Infantry Shields:
The press announces that the Yawata Steel Works is to manufacture a large number of bullet proof shields and steel helmets for the War Department. The shield is so constructed that it can be folded and carried in the knapsack.
The practical value of such a shield is doubtful, but where an American infantryman, if so equipped, would throw this extra weight away at the first opportunity, a Japanese, if taught that it was a part of his fighting equipment, would undoubtedly carry it for miles in order to use it in action.
G-2 Report: Japan (Military), dated 1926-04-30.
Helmets – Each man in the company is issued a helmet and has it in his possession. However, in none of the maneuvers so far this year has it been worn. It is similar in shape to the French and has a sort of visor effect in front. Its weight, color and padding on the interior is very similar to our own.
Report of American officer attached to the 37th Infantry Regiment, dated 1926-12-09.
MISCELLANEOUS.
Steel Helmets – The steel helmet which was carried on hand in the companies was somewhat similar to the trench helmet in shape.
Report of American officer attached to the 9th Infantry Regiment, dated 1927-12-09.
Helmet – The helmet is of metal, its outward appearance resembling the French one except that there is no boss on the top of it and that the brim in the rear is less wide than in front, being cut away to prevent its interfering with the pack and being pushed forward over the wearer’s eyes when he lies down. On the inside is a net of strings serving as a cushion. The helmet is held on the head by two Y shaped cloth bands, the two upper ends of each of which are attached to the inner band of the helmet, one at a point just in front of the ear and another just behind, the junction of the Y being about 4 inches below the edge of the helmet. The two strips are then tied under the chin. This arrangement seems to hold the helmet in place very steadily, but it seemed as if it might be hard to get off in a hurry in order to put on the gas mask. This article was not issued generally but is included in the list of equipment for same reason given in the case of the gas mask.
Report of Captain Harry T. Creswell about his attachment to the 38 Infantry Regiment, dated 1927-12-23.
Examining a Model 3 Navy Helmet
Here are some points unique to Model 3 navy helmets
A look at the "Made in Japan" Chinese Helmet of 1930
Requested by the surplus weapons exporter, Taihei Association, here's the helmet made by the Osaka Arsenal for Chiang Kai-shek's Kuomingtang army, fighting Mao's communists.
Helmet Cover Authentication
Army helmet cover repros are all over the place these days. So I'm anchoring the authentication thread here for your easy access.
Of ㊁ markings and Navy Type 3 Helmets
㊁ markings as indications of use of a different grade of steel as I suggested in another thread is now almost a certainty. The fate of Type 98 shovels in late 1943 strongly supports that hypothesis.
At the same time, switch-over to alternative steel for helmets, such as use of Ducol steel may very well explain why Type 3 helmets, theoretically expected to weigh nearly 1400 grams simply do not seem to exist in collections. That is, it is highly likely that less bullet-proof, but lighter steel came into use, because of shortages in such materials as chromium and nickel that progressively worsened since around 1941.
The navy was already the biggest user of Ducol steel in Japan at that time, so a switching of helmet steel by the navy is by no means a farfetched hypothesis.
Rather than weight, an accurate and easy way to gauge the steel thickness of the shell becomes the key to identifying Type 3s in that event.
Last edited by Nick Komiya; 08-14-2022 at 06:32 PM.
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