The chain would create interesting blocking blocking terrain for vehicles. Any vehicle crossing the chain may become entangled in the chain, dragging the aforementioned 100kg of HE and twitchy contact fuses across the ground towards the vehicle.
I shall nab that idea.
Of course the mine might be detonated just by a vehicle hitting the chain too.
I was thinking of using the mines as objectives too - if munitions are in short supply a field full of HE that can just be harvested by men with a spanner and a wheelbarrow could be very tempting.