Section 238.421 - Glazing(a)General. Except as provided in paragraphs (b) and (c) of this section, each exterior window on a passenger car and a power car cab shall comply with the requirements contained in part 223 of this chapter.(b)Particular end-facing exterior glazing requirements. Each end-facing exterior window in a passenger car and a power car cab shall also, in the orientation in which it is installed in the car: (1) Resist the impact of a 12-pound solid steel sphere traveling(i) at the maximum speed at which the car will operate(ii) at an impact angle no less severe than horizontal to the car, with no penetration or spall. An impact angle that is perpendicular (90 degrees) to the window's surface shall be considered the most severe impact angle for purposes of this requirement; and(2) Demonstrate anti-spalling performance by the use of a 0.001-inch thick aluminum witness plate, placed 12 inches from the window's surface during all impact tests. The witness plate shall contain no marks from spalled glazing particles after any impact test; and(3) Be permanently marked, prior to installation, in such a manner that the marking is clearly visible after the material has been installed. The marking shall include: (i) The words "FRA TYPE IHP" to indicate that the material has successfully passed the testing requirements specified in this paragraph;(ii) The name of the manufacturer; and(iii) The type or brand identification of the material.(c)Passenger equipment ordered prior to May 12, 1999. Each exterior window in passenger equipment ordered prior to May 12, 1999, may comply with the following glazing requirements in lieu of the requirements specified in paragraphs (a) and (b) of this section: (1) Each end-facing exterior window shall, in the orientation in which it is installed in the vehicle, resist the impact of a 12-pound solid steel sphere traveling(i) at the maximum speed at which the vehicle will operate(ii) at an impact angle no less severe than horizontal to the vehicle, with no penetration or spall. An impact angle that is perpendicular to the window's surface shall be considered the most severe impact angle for purposes of this requirement.(2) Each side-facing exterior window shall resist the impact of a:(i) 12-pound solid steel sphere at 15 mph, at an angle of 90 degrees to the window's surface, with no penetration or spall; and(ii) A granite ballast stone weighing a minimum of 0.5 pounds, traveling at 75 mph and impacting at a 90-degree angle to the window's surface, with no penetration or spall.(3) All exterior windows shall:(i) Resist a single impact of a 9-mm, 147-grain bullet traveling at an impact velocity of 900 feet per second, with no bullet penetration or spall; and(ii) Demonstrate anti-spalling performance by the use of a 0.002-inch thick aluminum witness plate, placed 12 inches from the window's surface during all impact tests. The witness plate shall contain no marks from spalled glazing particles after any impact test; and(iii) Be permanently marked, prior to installation, in such a manner that the marking is clearly visible after the material has been installed. The marking shall include: (A) The words "FRA TYPE IH" for end-facing glazing or "FRA TYPE IIH" for side-facing glazing, to indicate that the material has successfully passed the testing requirements of this section;(B) The name of the manufacturer; and(C) The type or brand identification of the material.(d)Glazing securement. Each exterior window on a passenger car and a power car cab shall remain in place when subjected to:(1) The forces due to air pressure differences caused when two trains pass at the minimum separation for two adjacent tracks, while traveling in opposite directions, each train traveling at the maximum authorized speed; and(2) The impact forces that the glazed window is required to resist as specified in this section.(e)Stenciling. Each car that is fully equipped with glazing materials that meet the requirements of this section shall be stenciled on an interior wall as follows: "Fully Equipped with FRA Part 238 Glazing" or similar words conveying that meaning, in letters at least 3/8 of an inch high.64 FR 25660, May 12, 1999, as amended at 67 FR 19992 , Apr. 23, 2002