In the UK, the Health & Safety Executive (HSE) produce guide lines GS.6 for working safely under power lines, it is a document for purchase, a synopsis is available at the following link. http://www.hse.gov.uk/pubns/ais8.pdf
Suggest you look at "Short Circuit calculations - the Easy Way" by J.R.Seiver PE & John Paschal PE - ISBN 0-87288 - 745 -6 for another alternative, I got my copy via AMAZON.
Alternative to Silicon Grease is SILIDRIEL a silicone based paint which is sprayed onto insulator strings. Elecricidad federal de Mexico use it frequently to avoid similar tripping situations. Advantage of paint over grease is that you simply re-spray when neccessary, NO complex time consuming...
You might also try Engineering Recommendation G74 -Proceedure to meet the requirements on IEC 909 for the calculation of short-circuit currents in three-phase ac power systems.
The document is available from the UK Electricity Association web site (pay for)
In the Veracruz area of Mexico they have a pollution problem which occurs during their winter, when salt laden winds blow off the Gulf of Mexico. Severly polluting insulators, they had many insulator flashovers during mornings of high humidity.
Spraying the insulators with SILIDRIEL a silicone...
