[Code of Federal Regulations] [Title 47, Volume 1] [Revised as of October 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 47CFR17.45] [Page 855] TITLE 47--TELECOMMUNICATION CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION PART 17_CONSTRUCTION, MARKING, AND LIGHTING OF ANTENNA STRUCTURES--Table of Contents Subpart C_Specifications for Obstruction Marking and Lighting of Antenna Structures Sec. 17.45 Temporary warning lights. During construction of an antenna structure, for which red obstruction lighting is required, at least two 116- or 125-watt lamps (A21/TS) enclosed in aviation red obstruction light globes, shall be installed at the uppermost point of the structure. The intensity of each lamp shall not be less than 32.5 candelas. In addition, as the height of the structure exceeds each level at which permanent obstruction lights will be required, two similar lights shall be installed at each such level. These temporary warning lights shall be displayed nightly from sunset to sunrise until the permanent obstruction lights have been installed and placed in operation, and shall be positioned so as to insure unobstructed visibility of at least one of the lights at any normal angle of approach. If practical, the permanent obstruction lights may be installed and operated at each required level as construction progresses. [32 FR 11273, Aug. 3, 1967, as amended at 39 FR 26157, July 17, 1974; 42 FR 54826, Oct. 11, 1977]