Vietnam Era Low Dome M-1

[Bugme]

Since a forum member recently added a side by side profile shot of the M-1 'Low Dome' along with the WWII M-1 to the forum in another thread, I have taken the photo and begun this reference thread concerning the Vietnam era 'Low Dome' helmet.

 

The low dome was the Army's effort at creating a lower profile M-1 helmet so as to gain maximum concealment. The result was a helmet about a 1/2" lower in the dome than it's WWII predecessor. Not a great deal of difference until you try to get a WWII liner to fit in one of these properly. The old liner will stick out about a quarter inch around the bottom edge and will not go in any farther. Did the Army gain an advantage with this 1/2' lower profile? As far as I know, there was not any kind of tactical advantage gained by these. However, it does frustrate a lot of newbie collectors and reenactors when they try to fit the older liner into the pot and can't understand why it sticks out so much farther than their friends.

 

Photo Credit Forum Member: hhc1stidf

[Grant G.]

That was a big problem with me when I was younger and I was getting quite frustrated with myself. "My helmet looks just like theirs, but why does it stick out?" I probably purchased 3 Korean war liners at the age of 12 before I learned they don't make liners in different sizes. I kept seeing a number (ink) stamped into the liner (say a 7) I would say to myself "Ok I just need to get one stamped with a 6, and it will work". The worst part of all was no one around me could help me because I was the only family member who collected military items. Sorry to rant but I thought I would share my story.-Grant

[craig_pickrall]

There is an opposite side to this coin too. The earliest M1 helmets were larger than the later WW2 helmets. A Hawley liner will drop right in these early helmets but will stick out the bottom of the later helmets. It is much like what a WW2 or Korean era liner does with these low dome VN era helmets.

[JollyGreenSlugg]

Thank you. I've been looking all over for a comparison photo to show the differences.

 

A picture does tell a thousand words.

 

Cheers,

Matt

[TonyD]

I was wondering if anyone has copies of the tech orders or manufacturing drawings for the "Low dome" helmet. I've seen lots of discussion regarding this matter, and was just curious.

 

The reason I ask is while recently re-reading Mark Reynosa's Post-World War II M-1 Helmets, I started to look more closely at the engineering drawings he has included in the book.

 

In Chapter 8, on Page 32, there is a copy of drawing D2-1-87, dated March, 1951. The baseline vertical measurement of the helmet dome appears, under magnification, to show a height of 6-9/16th inches.

 

Then in Chapter 13, on Page 79, there is a copy of the the Army Natick Laboratory's Drawing 2-1-87 Revision #6, dated 25 August 1966. . On this drawing the same baseline measurement shows a height of 6-9/16th inches.

 

Is there a similar Natick Laboratory Drawing post dating Revision #6 that shows the shorter dimension?

 

I've only seen one comparison photo, repeated on this Forum and other places that appears to show a "Viet-nam era helmet" compared to a WW2 or KW Helmet. It certainly appears lower, but I also have compared Schlueter and McChord helmets from WW2 and perhaps it is just my "eye" but the Schlueter appears taller.

 

Unfortunately, Mr. Reynosa's excellent book does not have similarly dated KW era and VN era liner production drawings to obtain a similar comparison.

 

I've begun to wonder if the real issue isn't so much the helmet shell as changes in the liners. As Mr. Reynosa points out and illustrates in his M-1 Helmet books there was the WW2 High-Pressure liner, the KW Liner (1951-54), what I'll call the Cold War liner (1955-1963) and finally the VN Liner (1964-1969). These were all M-1 Liners made of Resin impregnated cotton duck. Then in 1964, there was introduced the Combat Liner made of laminated ballistic nylon (1964-1974) and finally the Combat Liner made with the removable suspension (1972-1984).

 

As Mr. Reynosa discusses there were numerous liner manufacturers. Some of the molds were owned by the Federal Government and were "issued" (my word) to the various manufacturers. In one example he cites where the manufacturer dispatched their engineers to the government facility to select the molds they would use for a production run. He also discusses the various means of finishing the edges and securing them during fabrication.

 

Is it possible that the real issue is changes in the liner as opposed to changes in the M-1 shell.

 

Please excuse my curiosity on this matter. In the meantime, I'll get one of my helmets off the shelf in expectation for an incoming barrage on this matter.

[Sgt. Stubby]

There seems to be a lot of hearsay and conjecture regarding the LOW-DOME M1 HELMET. I've been doing a little research and will post as I prepare the material.

A few comments lifted from USMF:

"Is it possible that the real issue is changes in the liner as opposed to changes in the M-1 shell."

"Low dome really is just a term used for any and all post WW2 helmets. If you mean information on why they lowered the profile of the shell by what, half an inch? I dont think anyone really knows for sure."

"The low dome was the Army's effort at creating a lower profile M-1 helmet so as to gain maximum concealment."

Here are my questions.

Q1. Did the M1 Helmet ACTUALLY change to a lower profile low-dome shape?

A1. Yes. Proof is in collector's experience placing high-dome liners into low-dome shells.

Q2. WHEN did the low-dome M1 helmet supercede the WW2 "high-dome" version?

A2. Unknown date. Surely someone can give a definitive answer with correlating facts?

Q3. WHAT is the difference in height of the 2 versions?

A3. I don't know. 1/2"? Can someone grab a yardstick and find out?

Q4. WHY did the US change to a lower profile helmet?

A4. BETTER BALLISTIC PROTECTION WITHOUT ADDITIONAL WEIGHT. I have some evidence backing up this claim. I'll post when I have it ready to share.

ANY OTHER QUESTIONS about the LOW-DOME M1 HELMET?

 

[Sgt. Stubby]

Q1. Did the M1 Helmet ACTUALLY change to a lower profile low-dome shape?

A1. YES

Using the excellent comparison photo above, I outlined both the WW2 and Low-dome M1 Helmets. Using actual photographic evidence we can clearly see the difference.

 

 

[Pepper]

I am not able to comment on design changes regarding alterations to the M1 helmet's requirements due to the need for better concealment or ballistic increase as I have not read anything relating to this. If there is any potential study into the depth of the helmets draw specific to ballistics I would imagine that would be found in the studies and experimentation done in the late 1960s into the 1970s helmet program.

The first steel helmet bodies pressed at a more shallow draw or "lower profile" from that of the first helmet bodies pressed by McCord were manufactured at Schlueter Manufacturing Co. during WWII. The M1 helmet suffered from its inception with post manufacture breakage or stress cracking due to the 7 inch deep draw required by the helmets design. Experimentation with steel was performed at McCord while changes in the pot design were experimented on at Schlueter. The Ordnance Department scheduled these changes to happen at Schlueter as they were tooling up to run helmets whereas McCord already had their tooling in place. The reduction in the depth of the draw was done in an attempt to minimize or eliminate cracking and breakage caused by the depth of the draw. Cold working the steel was another main contributor to stress cracking. Cold working was primarily done to form the front visor of the helmet back down in the opposite direction of the initial draw. The design change to the visor and slope of the front of the helmet is easily discerned when comparing the profile of a Schlueter helmet body to that of the McCord helmet body.

Records from Watertown Arsenal detail these tests and how they were conducted.