SIS SS 436 02 53-1980 Overhead Ii ne crossings — High voltage overhead line, max. 45 kV, above railway — Reinforced construction — Crossing span safe for faIIing trees
1980SIS SS 436 02 53-1980 Overhead Ii ne crossings — High voltage overhead line, max. 45 kV, above railway — Reinforced construction — Crossing span safe for faIIing trees