I have a Industrial client with a large freestanding bridge crane. It is outdoors. Approximately 600lf in length X 70' width x 60' height. The client has had some problems with lighting strikes damaging drives an some other electrical components on the bridge crane. The bridge crane does not have a 4th bus for the equipment ground as required by the NEC.

Besides the 4th bus for the equipment ground issue, I need information(literature, published standards) on possible lighting protection, grounding and bonding of the steel support structure.

There isn't any lightning, grounding or bonding on any part of the structure at this time. This structure has been in place since mid 1970. The only ground that I can find is the equipment ground(#6awg) brought in with the power feeder to the Crane disconnect. The Disconnect is mounted to the support structure on one side. The other side of the support structure does not have any type of grounding, bonding etc.

I see dangerous touch potential electrical hazards associated with this installation in its current state.