Section 229.133 - Interim locomotive conspicuity measures-auxiliary external lights(a) A locomotive at the head of a train or other movement is authorized to be equipped with auxiliary external lights, additional to the headlight required by § 229.125 , for the purpose of improved conspicuity. A locomotive that is equipped with auxiliary external lights in conformance with the specifications or performance standards set forth in paragraph (b) of this section on the date of issuance of a final rule that requires additional or other external lights on locomotives for improved conspicuity, as required by section 202(u) of the Federal Railroad Safety Act of 1970, shall be deemed to conform to the requirements of the final rule for four years following the date of issuance of that final rule.(b) Each qualifying arrangement of auxiliary external lights shall conform to one of the following descriptions: (1)Strobe lights.(i) Strobe lights shall consist of two white stroboscopic lights, each with "effective intensity," as defined by the Illuminating Engineering Society's Guide for Calculating the Effective Intensity of Flashing Signal Lights (November 1964), of at least 500 candela.(ii) The flash rate of strobe lights shall be at least 40 flashes per minute and at most 180 flashes per minute.(iii) Strobe lights shall be placed at the front of the locomotive, at least 48 inches apart, and at least 36 inches above the top of the rail.(2)Oscillating light.(i) An oscillating light shall consist of: (A) One steadily burning white light producing at least 200,000 candela in a moving beam that depicts a circle or a horizontal figure "8" to the front, about the longitudinal centerline of the locomotive; or(B) Two or more white lights producing at least 200,000 candela each, at one location on the front of the locomotive, that flash alternately with beams within five degrees horizontally to either side of the longitudinal centerline of the locomotive.(ii) An oscillating light may incorporate a device that automatically extinguishes the white light if display of a light of another color is required to protect the safety of railroad operations.(3)Crossing lights.(i) Crossing lights shall consist of two white lights, placed at the front of the locomotive, at least 36 inches above the top of the rail.(ii) Crossing lights shall be spaced at least 36 inches apart if the vertical distance from the headlight to the horizontal axis of the ditch lights is 60 inches or more.(iii) Crossing lights shall be spaced at least 60 inches apart if the vertical distance from the headlight to the horizontal axis of the ditch lights is less than 60 inches.(iv) Each crossing light shall produce at least 200,000 candela, either steadily burning or alternately flashing.(v) The flash rate of crossing lights shall be at least 40 flashes per minute and at most 180 flashes per minute.(vi) Crossing lights shall be focused horizontally within 15 degrees of the longitudinal centerline of the locomotive.(4)Oscillating light.(i) An oscillating light shall consist of:(A) One steadily burning white light producing at least 200,000 candela in a moving beam that depicts a circle or a horizontal figure "8" to the front, about the longitudinal centerline of the locomotive; or(B) Two or more white lights producing at least 200,000 candela each, at one location on the front of the locomotive, that flash alternately with beams within five degrees horizontally to either side of the longitudinal centerline of the locomotive.(ii) An oscillating light may incorporate a device that automatically extinguishes the white light if display of a light of another color is required to protect the safety of railroad operations.(c)(1) Any lead locomotive equipped with oscillating lights as described in paragraph (b)(2) of this section that were ordered for installation on that locomotive prior to January 1, 1996, is considered in compliance with § 229.125(d)(1) through (3) .(2) Any lead locomotive equipped with strobe lights as described in paragraph (b)(1) and operated at speeds no greater than 40 miles per hour, is considered in compliance with § 229.125(d)(1) through (3) until the locomotive is retired or rebuilt, whichever comes first.(3) Any lead locomotive equipped with two white auxiliary lights spaced at least 44 inches apart on at least one axis which was equipped with these auxiliary lights before May 30, 1994, will be considered in compliance with § 229.125(d) (1) through (3) until the locomotive is retired or rebuilt, whichever comes first.58 FR 6902, Feb. 3, 1993, as amended at 59 FR 24963, May 13, 1994; 59 FR 39705, Aug. 4, 1994; 61 FR 8887, Mar. 6, 1996; 77 FR 21348 , Apr. 9, 2012