The West Side Substation of the Forest Grove, OR. Municipal Light & Power system. 120,000 volts of Bonneville power enters on the far end and 4, 3-phase 12,500 volt city distribution lines emerge from the end shown closest in the photo. Plenty of older brown porcelain insulators and switch insulators in this sub. although the line closest to the fence has been re-insulated with sky-gray yuks.