M12 A1 Practice Antitank Mine

[Story]

More dusty relics. 

How's everybody's AFVID skills these days?

 

For the longest time, I thought this was an M19 practice mine (because that's what we had for training) but the M12 and M19 are really similar.

[See upper left corner for dimensions]

[Story]

For those of you who missed the Cold War, this was part of the training to stop the Soviet hoard.   https://www.youtube.com/watch?v=sfPKO0DI4Vk

The urgency was articulated by the Drill Sergeants at Fort Knox (most of them having spent the majority of their careers with Armor and Cavalry units on the inter-German border) with "if your platoon has to cover the Battalion withdrawal, your life span will be two minutes thirty seconds so pay attention to the next block of training".

 

So we learned how to lay and arm anti-tank mines. 

[Story]

I get the sense (but can not find any supporting documentation) that these mines were fielded to stop a potential Chinese heavy armor attack in Korea. 

 

There's not much out there on post-WW2 US AT mine development, so if anyone has input feel free to jump in here.

https://en.wikipedia.org/wiki/M15_mine

 

 

https://www.globalsecurity.org/military/library/policy/army/fm/5-102/index.html

[thorin6]

Checking mine, I guess it's the M20, being about 5 inches thick.  In Germany we learned how to lay a minefield and put anti-handling devices on them, and I taught their use to new LTs at the Engineer Basic Course and the National Guard.  Nothing particularly mysterious about their use to stop armored vehicles.  We had manuals and graphic sheets to help set minefields up.  The biggest thing was properly recording minefields so we knew where they were when we counterattacked.

By the way, once a mine is armed, he is no longer your friend.

[Story]

12 hours ago, thorin6 said:

Checking mine, I guess it's the M20, being about 5 inches thick.  In Germany we learned how to lay a minefield and put anti-handling devices on them, and I taught their use to new LTs at the Engineer Basic Course and the National Guard.  Nothing particularly mysterious about their use to stop armored vehicles.  We had manuals and graphic sheets to help set minefields up.  The biggest thing was properly recording minefields so we knew where they were when we counterattacked.

By the way, once a mine is armed, he is no longer your friend.

 

Yeah, the text out there claims they were only expected to get M-Kills but I remember a lexan (?) wiggler rod that got installed on the fuze that would get triggered when the lower front glacis of a tank hit it. You could also double-stack these things for bigger bangs.

 

Another vague memory was tricks on laying a hasty minefield, in that you looked for a choke-point spot. The first mine got laid where you'd expect their lead tank to hit it, then the second and third where the two follow on tanks would break wide to avoid the burning number one wreck.  Theoretically, that'd ruin a Soviet three-tank platoon's day.

 

That'd also explain them being shipped in boxes of three.

 

[thorin6]

Yes, we had tilt rods so if the vehicle didn't put its treads or wheels over the pressure plate, the tilt rod would blow the mine up right under the thin bottom.

We also could do hasty minefields by just laying the mines on the ground and covering them with leaves or some dirt.  Tanks without infantry wouldn't see them and would still have to avoid the field.

Interestingly, in Desert Storm, against the Iraqi minefields, we saw that in the early morning hours and later evening hours, the thermal sights on the Abrams Tanks could see the heat signatures, as the mines heated up and cooled down at different rates than the surrounding soil during those times.

We also learned to intersperse anti-personnel mines among the anti-armor mine fields to make location and disarming a lot harder.

[Story]

So from this photo, the M15 had to be developed before the start of the Korean War.

 

 

Courtesy of Library of Congress, "South Korean soldiers of the 1st Division, I Corps, prepare and lay an antitank mine somewhere in Korea during the Korean conflict," 22 July 1950

Description

Landmines have been used in warfare for decades. The United States used M15 anti-tank mines for the first time in the Korean War. It was designed to be a "track breaker," causing a tank to no longer move but likely not killing the crew inside the tank.

via South Korean Soldiers Prepare and Lay an Anti-Tank Mine, July 22, 1950 | IDCA (iowaculture.gov)

 

Interesting that board sponsor IMA had one with it's carrying case.

https://www.ima-usa.com/products/original-u-s-korean-war-m12-antitank-practice-mine-with-carrier?variant=31891743834181

[Story]

 From this description, sounds like the M15 was a refinement of the M6 AT mine.

 

By late August 1943 the Ordnance Department had four pilot models ready for test. Both the Ordnance Technical Division and the Engineer Board’s Technical Staff preferred the one designated T6E1. This had a thin metal shell, weighed twenty pounds, and contained twelve pounds of TNT, thus fulfilling the Ground Forces requirement that the mine be 60 percent explosive. Offering the greatest possible area to tank tracks, the mine case was about three inches high and thirteen in diameter, and had activating wells in the sides and bottom for booby trapping. Inside, a stack of four Belleville springs supported the pressure plate and provided the tension fixing the 350-pound load under which the fuze would function. The fuze well in the center was closed by a reversible plug that could be screwed down in either a safe or an armed position. This feature met the important requirement that arming be the last step in mine laying. The fuze was chemical, similar to that of the nonmetallic mine.26

 

p.386, Chapter 13: The Development of Better Protection

To those who served...

http://tothosewhoserved.org/usa/ts/usatso01/chapter13.html

 

So, made to stop Tiger tanks.

 

 

...and this is the other end of the time window.

 

STATUS: The M15, M19 and M21 AT mines were last procured in FY52, FY58 and FY62 respectively. 

https://fas.org/man/dod-101/sys/land/atm.htm

[Brian Keith]

Thanks for all the interesting information! This thread is a gold MINE of information.

BKW 

[Story]

 Looks like the series went from the M6 

https://bulletpicker.com/landmine_-at_-m6.html

directly to the M15

 https://bulletpicker.com/landmine_-at_-m15-and-practice.html

 

..since the M7 AT mine (and it's M10 practice version) looked like a lethal binoculars case.

https://bulletpicker.com/landmine_-at_-m7.html

 https://bulletpicker.com/landmine_-practice_-m10.html

[Story]

Well now, look at what conclusion our own @ChrisNZcame to -

only to come to the conclusion that the M12 is exactly the same as a WW2 M6 (other than it being a practice mine).

 

https://www.usmilitariaforum.com/forums/index.php?/topic/167406-m6-anti-tank-mines/

 

Note that these photos (both dated 11 July 1944) show the mine without markings, painted a solid olive drab.

 

M6 anti-tank mine showing fuse and activator taken out with removal of plug.

https://www.ww2online.org/image/mine-shown-fort-benning-georgia-11-july-1944-4

https://www.ww2online.org/image/mine-shown-fort-benning-georgia-11-july-1944-3

 

See also

https://www.lexpev.nl/minesandcharges/americas/unitedstates/minem6antitank.html

 

 

[Story]

More historical tidbits.

 

The necessity for some type of land mine w as becoming increasingly apparent as more and more enemy armor came in. At the outset w e25 had no source of antitank mines; however, on Tuesday, 27 June 1950, we received word that General MacArthur’s headquarters would support our efforts. We immediately asked for mines, and b y Friday we had received about eight hundred. The ROK troops had not had an y training in antitank mines. In fact, they had never seen an M 6 mine, but in this respect the y had nothing on me. I had never seen one either . However, I had an advantage in that I read and understand English fairly well, and the instructions are pasted on the inside of the individual mine’s carrying case. Shortly after the first mines were received, we instituted a short course on combat operations. We spent half an hour teaching the technique of laying and arming the M6 mines, and then we went off to the front.

 

p.24-25

 

62. Who’s Afraid of a Tank?

Capt. George R. Spreng, Korean Military Advisory Group The South Koreans had an extreme fear of tanks. This was not without cause, considering ho w unprepared they were to cope with them. In time the R OKs came to realize ho w restricted the tankers were, and how frightened were the crewmen. An incident occurred near Hamhung which pointed up the limitations of tanks. The Chinese Communists attached with four tanks out ahead of their infantry. Two of my ROK engineers each ran twice across the road dropping M 6 mines in the path of the tanks. All four enemy tanks were knocked out, and the attack w as stopped. The fear of tanks was much less thereafter.

p.242

 

Combat Support in Korea (koreanwar2.org)

https://www.koreanwar2.org/kwp2/cmh/combat_support_in_korea.pdf

 

So after all this, it looks like 1) the M12A1 is a training copy of the WW2 M 6 AT mine and 2) the M20 is the training copy of the M15 AT mine.

 

I've had my fun falling down this rabbit hole, I'll put the M12 A1 up for sale soon.

[Story]

PS - figured out why the M6 AT mine was 'new' to folks in South Korea circa 1950.

 

From p.387,

United States Army in World War II. The Ordnance Department Planning For War 

United States. Dept. of the Army. Office of Military History 1947

https://books.google.com/books/about/United_States_Army_in_World_War_II.html?id=hqVkx_sYyAQC
 

Because of the urgent need in the summer of 1943 for the heavy antitank mine and the hasty mine, procurement began that fall before either was standardized. After correction of minor defects in the components , notably a tendency to leak , it was standardized in September 1944 as the M6. At the same time the hasty mine was standardized as the M7 . Thanks to the early procurement program,  2,500,000 M6 mines and 750,000 M7's were on hand in the zone of the interior. There were none in the European theatre. 

 

* 

While General Barnes' faith in them appears to have been justified, the new mines came too late . Except for the break-through in the Ardennes in December 1944 , U.S. forces were on the offensive from D Day on and had only restricted need for field fortifications and obstacles .  

 

  And from p.4 of Change 1

TM 9-1940 LAND MINES C 1 (15 July 1943)  

TM 9-1940 (ibiblio.org)

https://archive.org/details/TM9-1940

https://www.ibiblio.org/hyperwar/USA/ref/TM/pdfs/TM9-1940.pdf

 

It is painted olive-drab, with markings stenciled in yellow.   

 

Note that this is different from the actual practice of OD green w/o yellow stenciling, as evident in the 1944 photos above.