[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR236.73] [Page 547] TITLE 49--TRANSPORTATION CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 236_RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, Subpart A_Rules and Instructions: All Systems Sec. 236.73 Open-wire transmission line; clearance to other circuits. Open-wire transmission line operating at voltage of 750 volts or more shall be placed not less than 4 feet above the nearest crossarm carrying signal or communication circuits.