Here is a nice little gadget i came across in my local area a couple of years ago.
It's a British Mark one Magnetic moored mine. This mine is part of a minefield that the british placed here on the 8.th of April 1940 (The day before the German invasion of Norway in 1940)
This was actually a breach of Norway's neutrality by the British, as they placed mines in the middle of norwegian civillian sea-lanes.
The mine is placed up-side-down, as the Mooring mechanism would be facing down in the water
By the way, this example is empty and does not contain any dangerous substances.
The magnetic mine had a rather ingenious trigger mechanism. In a easy and understandeble explanation, It had an elecric coil that would detect the signature of a large metal hull (boat or ship) that was passing by, and if close enough it would generate a low electric current, wich would set of the detonators and the main charge.
The main charges on these mines consisted of a barrel containing 280 pounds (127 Kg) Amatol - wich is a mixture of TNT and Ammonium nitrate, wich would provide a huge detonating effect when set off.
These mines were known to detach themselves from the anchor after some time, and would be washed ashore. The good news with these mines, is that the Mooring mechanism had a very good safety function. If the wire was to break, and the mine lost the tension on the wire from the anchor, a strong springloaded mechanism would disarm the mine, preventing it from detonating.
Anyway, these mines were placed in the middle of shipping lanes in Vestfjorden. The minefield is marked on the map here:
In the upper part of the map you see Narvik.
And on this I have marked with a small red dot, where I live. Only a few hundred meters from where the minefield started:
The anchoring mechanism on these mines, were alo a brilliant mechanical patent.
Anyway, my example is standing up-side-down as you can see. The top lid is unfortinently missing.
I am looking for a top lid to complete the hull of this mine, so if anyone know where I can find one of these, i would be very interested
Best Regards
Björn