As part of safe system of work on a known cable, spiking provides physical proof that a cable is dead at the point of work. Typically a tone generator is applied to the cable under a test document, the tone is obtained at the point to be spiked and the cable spiked with the tone on (the tone should be lost past the point of spiking as the chisel blade of the spiker acts as a short if successful). Typically the tone generator is then removed, earths reapplied and the test document canceled. A work document can then be issued and the cable cut adjacent to the spiker prior to its removal and the commencement of work proper.
http://www.theiet.org/forums/Forum/messageview.cfm?catid=226...

Step 13
13.1 Ensure that the spike has fully penetrated the cable by following the procedure in...
http://www.cablejoints.co.uk/upload/Central_Networks_eon___C... [na rysunku widać ten "spike"]

Nie wiem jednak, czy o takie "spiking" chodzi...