Interpretation ID: aiam3059
Chief Engineer
Ontario Bus Industries Inc.
5395 Maingate Drive
Mississauga
Ontario;
Dear Mr. Bigwood: This responds to your July 16, 1979, letter asking two questions abou the test procedures of Standard No. 217, *Bus Window Retention*, as they apply to buses you manufacture.; First, you ask whether side service doors can be counted in determinin the proper amount of bus emergency exits as required by the standard. As long as side service doors comply with all requirements applicable to emergency doors, they can be considered emergency exits for purposes of compliance with the standard.; Your second question asks whether glazing in a door is tested fo window retention, and if so, whether it is tested while the door is installed in a bus. The answer to both parts of this question is yes. All bus glazing, that is of the minimum size specified in the standard, must comply with the window retention requirement. The intent of the window retention requirement is to prevent openings in buses that might result in the ejection of occupants from the vehicle during an accident. In order for this requirement to have meaning, the glazing must be tested as it is installed in the vehicle to ensure the integrity of both the glazing and its surrounding structure. This means that glazing in vehicle doors is tested while the door is in the normal closed condition. If the door opens during the test, the vehicle would not be in compliance with the requirements.; Sincerely, Frank Berndt, Chief Counsel