LIGHTNING CIRREXTS I.\ BURIED CABLE 



293 



Table I 

 Summary of Currents Exceeding 10 KA 



* For location of strokes, see Fig. 6. 

 ** Measured at stroke point. 



lO 35 



5 25 



M 20 



<J 10 



tr 



10 CD 



Si 



?2 



UJ ^ 



2 t) 



O^ 



65432101 23456 



DISTANCE ALONG CABLE (FROM ESTIMATED STROKE POINT) INKILOFEET 



Fig. 8 — Variation in crest current, voltage, and charge along cable for max. observed 

 stroke current of 70 ka, having a time to half-value of 130 microseconds. Dashed curve 

 shows theoretical variation of current for this time to half-value and an earth resistivity 

 of 1200 meter-ohms. Variation in voltage between sheath and copper shield indicates 

 breakdown between sheath and copper shield near stroke point. 



