That certainly is a contributing factor Edwin but the trial hole process checks if a location is clear to pile, be it clear of cables, lengths of old rail, drains, culverts etc. In areas where there are a lot of cables shown on the records we excavate a slit trench and once a clear spot if found we can ask for the foundation to be redesigned and located in the clear spot, it's not always possible but it's the first and best option. In Swindon we found the timber supports of the original station, they're pretty substantial and would most definitely cause an issue if you tried to drive a pile through without checking first.
Good to get these contributions from the horse's mouth, so to speak, thank you. Makes one wonder why the issue of buried cables was cited so prominently by the NR CEO a while back. In any event, the late Mr Cardani's record stands intact and that is very pleasing.