The M6 is one of those military options that the US Army pursued and then dropped. Through 1940 and the beginning of the war the US Army initiated these various armored vehicle and self propelled gun project as stopgaps and in response to evolving doctrine. As the war progressed and these various vehicles proved to be redundant, the programs were reduced to a barely sustained level and then canceled altogether. So if the question is ever asked why the US didn’t design a heavy tank, the answer is that they did. Then the Armored forces decided that the gains were not worth the resources.
I first heard of this project reading about it in Ian Hogg’s book Artillery back in the 1970’s. That book didn’t have too many details and I’ve never really thought about it much since. This post has most of the details and what the V3 was about.
Apparently there is a documentary coming out about the guns and their installation. The fact is that this thing would never have succeeded because it’s was too obvious and too big a target. And it would have solved any of Germany’s strategic problems even if had been deployed and used. The ammunition for the gun was about the same size as the Qassam rockets that Hamas uses to hit Sredot and as about as accurate. And Germany had no way of determining the effect of the weapon and would be firing blind. In the end this was a waste of resources that Germany desperately needed elsewhere
Now from the pictures it’s fairly obvious that it’s a contact mine. I didn’t know what type so I consulted my copy Naval Ordnance and Gunnery, which dates back to 1950 or so and covers the weapons used in WW2.
Sure enough, in the section on mines this picture showed up diagramming the Mark 6 contact mine. The book covers the mine and how it works.
Here’s how it deploys.
And a diagram of the detonator. In the pictures on the Popular Mechanics article you can clearly see the firing mechanism, or what’s left of it, which are some rusted chunks.
There’s also the fact that the mine was electrically detonated and the batteries were long dead. So the possibility of the mine going off without somebody attaching a charge to it is rather slim. That being said deteriorated explosives may have reactive chemical in them and be a little unstable. Mines are usually designed to have plug that rusts out and causes the mine to sink to the bottom. I’m surprised that this one was still floating. Still, as long as you don’t go using the thing as wrecking ball, it’s very unlikely to go boom. As it hadn’t for 70 years of being knocked around the ocean, going through who knows what. Nothing a kid could possibly do it could be worse than what it’s already been through.
Here’s a nice page from the US navy on mines including the Mark 6.