Lightbuoy;12460; said:I'm guessing again here, but would the cables be to hold the blocks together, or perhaps are anchored individually, to prevent a tank from moving just one of the blocks?
Right m'dear, I've just spent some time on Google to check this out (what else is a girl to do on a friday night? )
And...some stuff...
"Cable of the railway barrier, set in it's concrete anchorage blocks, still guards the main line into Parkeston Quay."
From www.unlockingessexec.gov.uk
"Line of anti-tank blocks to hold a length of rail"
From www.nbcd.org.uk
"often holes at the top for the insertion of iron stakes which would have been lined with barbed wire in the hope that this would get tangled up in the tracks of any light tank trying to mount them"
From www.worcestershire.gov.uk
There's more, but I'm guessing that, as in the case of pillboxes, there would be variations according to the area and the interpreter of the original plans.
Hope that helps.
Cheers
Foxy