Boris

I never seen a sefety net in drilling site ,as i have been in diffirent rigs during last 10 years.Have you ever think how safetly net could be installed as there is alot of cables from crown block and othere winchs!!!!

SHV

My experience is primarily offshore, rather than construction, but I believe that netting on construction sites is used primary to catch people who fall, rather than dropped objects. I have seen vertical sheeting on construction scaffolds, which is primarily to provide wind protection for workers but also prevents light or heavier objects going over the edge. I've also seen angled solid protection above predestrial walkways.

Neither of these would work in a drilling rig, because of the many penetrations needed, as stated above in other responses. The usual approach on rigs is to:
a) ensure hand tools, etc. are on a lanyard, so don't go as far as the drill floor if dropped;
b) ensure all loose items are brought down after any maintenance or modification task above the drill floor - i.e. excellent housekeeping;
c) ensure regular checks on all large items which could deteriorate and fall, e.g. light fittings.

If these are done consistently, the added risk reduction from any net would be minimal, even if you could devise a suitable method to design, attach and maintain it in position.