Local power cut last week , the errant joint was laid by the trench so I had to nose.
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I laid a foot ruler laid over for scale. A few hundred houses affected but I assume this cable only supplied a few dozen, then the linesmen isolated the area transformer to fix the break , or do they work live? . Two cable ends marked by "O" . Tar infill not obviously burnt, just what seems to be an inadequate crimp had partly melted off the left hand end. I somehow expected something like a phosphorous cauldron like they use for welding railway line - not a crimp. And certainly not an open crimp as showing the flute betwen the "o"s in this closeup
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Orange is probably clay pipe surround, along with lead sheet inside that and then tar. Remaining cables showed no damage so no shorts. The end of the cable is cut clean across the wire strands and no sign of any brazing or the like. Wire strops and marine hawsers use a closed ring crimp hydraulically compressed on. How much of a bang would such 1 inch diameter cable failure make a couple of feet underground?