Backfilling the LBA

Now that the cables have been run out for the LBA, it is necessary to cover them with a layer of protective sand and then backfill with the soil and rock that was originally dug out. This is not easy, as the LBA trenching pattern is complicated and it is difficult for the diggers to manoeuvre between any partially filled trenches.

The first step is to apply the sand. A narrow bucket is attached to the digger and builders sand is scooped from the dumptruck into the trench. This is then carefully spread by hand to ensure that the cables are properly protected.


Once the sand is in place, the wide bucket is attached to the digger and the piles of chalk and soil are used to back fill the trench.