1、- 35115789 06114815 1189 CEMP-ET Technical Letter NO. 11 10-3-485 DEPARTMENT OF THE ARMY U.S. Army Corps of Engineers Washington, D.C. 20314-1000 ETL 11 10-3-485 15 October 1997 Engineering and Design FIRE PROTECTION FOR HELICOPTER HANGARS Distribution Restriction Statement Approved for public relea
2、se; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3535789 0834836 035 N CEMP-ET Technical Letter NO. 1 110-3-485 DEPARTMENT OF THE ARMY ETL 1110-3-485 U.S. Army Corps of Engineers Washington, D.C. 203 14-1 O00 15 October
3、1997 Engineering and Design FIRE PROTECTION FOR HELICOPTER HANGARS 1. Purpose. This letter provides criteria relative to the design and construction of fire protection features and systems at Army facilities. 2. e. This letter appiies to all HQUSACE elements and USACE commands having military constr
4、uction and design responsibility. 3. References. See Appendix A 4. - Approved for public release; distribution is unlimited. 5. Objective, There is currently no design criteria applicable to fire protection for helicopter facilities. Neither the Military Handbook (MLHDBK-lOOSC), Fire Protection for
5、Facilities, Engineering, Design and Construction nor NFPA 409, Aircraft Hangars, provides spdc fire protection requirements for helicopters. Consequently, various approaches to fire protection for Army helicopter facilities have been taken, resulting in a lack of uniformity in protection features pr
6、ovided Army-wide. This letter seeks to provide a uniformand cost-effective approach to helicopter hangar fire protection. 6. a. The guidance included in Appendii B to this technical letter will be used for planning, design and construction of fire protection features and systems for Army facilities.
7、 7. . . This technical letter will have special application, as defined in paragraph Sc, ER 11 10-345-100. FOR THE COMMANDER: 2 Appendices APP A - References APP B - Fire Protection For Helicopter Hangars This ETL supersedes ETL 11 10-3-467, dated 30 December 1994 Provided by IHSNot for ResaleNo rep
8、roduction or networking permitted without license from IHS-,-,-3515789 0814817 T51 = ETL 11 10-3-485 15 Oct 97 GOVERNMENT PUBLICATIONS Department of Defense MIL-HDBK 1008C Department of the Army ETL 1 1 10-3-484 APPENDIX A REFERENCES Handbook, Fire Protection For Facilities, Engineering, Design and
9、Construction US. Army Corps of Engineers, Engineering Technical Letter (ETL), Aircraft Hangar Fire Protection Systems, 26 September 1997 NONGOVERNMENT PUBLICATIONS International Conference of Building Officials, 5360 Workman Mill Road, Whittier, CA 90601 Uniform Building Code National Fire Protectio
10、n Association (NFPA), 1 Batterymarch Park, Quincy, MA 02269-9 1 O1 NFPA 10 Portable Fire Extinguishers NFPA 13 Sprinkler Systems NFPA 20 Centrifugal Fire Pumps NFPA 24 NFPA 70 National Electrical Code NFPA 72 NFPA 90A Private Fire Service Mains and Their Appurtenances National Fire Alarm Code Air Co
11、nditioning and Ventilating Systems A- 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3535789 0834838 998 W ETL 11 10-3-485 15 Oct 97 NFPA 101 NFPA 256 NFPA 409 Life Safety Code Fire Tests of Roof Systems Aircraft Hangars A-2 Provided by IHSNot for
12、 ResaleNo reproduction or networking permitted without license from IHS-,-,-3535789 OBL48L 824 ETL 11 10-3-485 15 Oct 97 APPENDIX B FIRE PROTECTION FOR HELICOPTER HANGARS TABLE OF CONTENTS Page . 1 . INTRODUCTION B-1 2 . BACKGROUND B-1 . 3 . GENERAL REQUIREMENTS B-1 3.1 Construction Type B-1 3.2 Exi
13、t and Access Requirements . B- 1 3.3 Distance from Other Buildings . B-1 3.4 Fire Area Limitations B-2 3.5 Internal Fire Separations B-2 3.7 Structural Steel Columns . B-2 3.8 Draftcurtains B-2 3.9 Interior Finish 3.1 O Floor Drainage . B-2 3.1 1 Heating Equipment B-3 3.12 Electrical Systems . B-3 3
14、.13 Fire Protection Systems and Equipment B-3 3.6 Roofs B-2 B-2 4 . SPRINKLER PROTECTION FOR HANGAR BAYS B-4 4.2 System Selection B-4 4.3 Foam-Water Sprinkler Systems . B-4 4.4 Water-Only Sprinkler Systems . B-5 4.5 ESFR Sprinkler Systems Design Requirements . B-6 4.1 SystemTypes B-4 B-i Provided by
15、 IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-= 3515789 O814820 546 ETL 11 10-3-485 15 Oct 97 Page 5 . FIRE PROTECTION WATER SUPPLY B-7 5.1 Water Storage . B-7 5.2 Exterior Hose Demand . B-7 5.3 Duration of Supply B-7 5.4 Underground Water Mains B-7 5.5 Firep
16、umps B-7 6 . FIFE PROTECTION SYSTEM DESIGN REQUIREMENTS B-8 6.1 Designer Qualifications . B-8 6.2 Technical Center of Expertise (TCX) B-8 6.3 Design Procedures B-8 6.3.1 Design Analysis B-8 6.3.3 Specifications B-9 6.3.2 Drawings . B-8 B-ii Provided by IHSNot for ResaleNo reproduction or networking
17、permitted without license from IHS-,-,-3535789 O834821 482 = ETL 11 10-3-485 15 Oct 97 1. INTRODUCTION Army helicopters are routinely housed in hangars and similar facilities in order to perform maintenance, make repairs, and provide protection from adverse weather. Because these aircraft are usuall
18、y fueled, they present a fire potential to the facility and the other valuable helicopters and equipment also contained in it. In order to protect against a possible mishap, various fire protection features and systems are essential. Sound fire protection engineering principles mandate a protection
19、system commensurate with the loss potential. Although the probability of a catastrophic fire event may be low, the severity can be high. To mitigate the loss potential, this ETL establishes requirements for cost-effective construction features and fire protection systems. This ETL recognizes the dif
20、ference in fire potential presented by helicopters as compared to fixed-wing aircraft and provides an alternative to conventional foam fire protection systems. 2. BACKGROUND This ETL has been prepared because there are currently no design criteria applicable to fire protection for facilities housing
21、 helicopters. Currently-published criteria focus on the hazards and fire potential associated with various sizes of fixed-wing aircraft. Attempts have been made by designers to apply the provisions of NFPA 409, Aircraft Hangars, to facilities housing helicopters. Unfortunately, NFPA 409 is applicabl
22、e only to facilities housing fixed-wing aircraft, not helicopters. Thus, in the absence of criteria specifically applicable to helicopter hangars, various approaches to fire protection have been taken. This has resulted in a lack of uniformity of protection features provided for Army helicopter hang
23、ars. This ETL specifically addresses the hazards and loss potential posed by helicopters and provides criteria for fire protection features and systems in new Army helicopter hangars as well as in retrofitting existing facilities. 3. GENERAL REQUIREMENTS 3.1 Construction Type. New hangar facilities
24、will be of noncombustibleconstruction (UBC Type I or Type II) in accordance with MIL-HDBK-1008C. 3.2 Exit and Access Requirements. Means of egress from aircraft facilities will comply with NFPA I 01, Life SafeS Code. 3.3 Distance from Other Buildings. Clear space around hangars will be provided to r
25、educe fire exposure between buildings and to assure access to such facilities from all sides. The requirements for clear space separation outlined in NFPA 409, Chapter 2, will apply. B-1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- 3535789 081482
26、2 319 = ETL 1 1 10-3-485 15 Oct 97 3.4 Fire Area Limitations. Helicopter hangar bay areas will not exceed 5576 m2 (60,000 ft). Where larger areas are required, fire walls having a minimum 3-hour resistance rating will be provided to limit hangar bay fire areas. 3.5 Internal Fire Separations. Walls a
27、nd ceilings separating helicopter hangar bays from attached, adjoining or contiguous shops, offices, parts storage or similar areas, will have at least 1 -hour fire resistive rating with openings protected by listed or approved fire doors having a minimum fire resistance rating of 45 minutes. 3.6 Ro
28、ofs. Roof coverings will be listed as Class “A“ or “BI when tested in accordance with NFPA 256, Standard Methods ofFire Tests of Roof Coverings. Where insulated metal deck assemblies are used, such will be equivalent to Factory Mutual Class I. 3.7 Structural Steel Columns. Protection of exposed stee
29、l columns is not required. 3.8 Draft Curtains. Draft curtains will be provided to form roof pockets with individual areas not exceeding 1394 m2 (1 5,000 ft). Draft curtains of non-combustible construction will be tightly fitted to the underside of the roof or ceiling and extend down not less than on
30、e-eighth the distance from the underside of the roof to the floor. Where permitted by roof structural framing systems, curtains will be affixed to steel trusses, joists or similar framing. For applications involving sloped roofs, draft curtains should run parallel with the roof slope. 3.9 Interior F
31、inish. All interior finishes will have a Flame Spread Rating of less than 25 and a Smoke Developed Rating of 50 or less. 3.1 O Floor Drainage. Floor drainage systems will be provided to limit the spread of fuel to mitigate the fire and explosion hazard fi-om fuel spillage. Systems will be designed u
32、sing underground piping routed to a safe outside location. 3.1 O. 1 The flow of liquids from helicopter hangar bay areas through wall openings will be prevented by installation of drains, ramps, curbs, or other suitable means. 3.10.2 The slope of the floor in the helicopter hangar bay areas will be
33、a minimum of one-half of one percent. Floors will be sloped in the direction of trench drains located at the main hangar doors or other location as required. 3.10.3 Determination of size of drainage piping will include consideration of the calculated maximum demand of installed fire protection syste
34、ms. 3.10.4 Oil Separators will be provided for drainage systems serving helicopter hangar bay areas. B-2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ETL 1 1 10-3-485 15 Oct 97 3.1 1 Heating Equipment. 3.1 1.1 Heating equipment will ,e in accordan
35、ce with the applicable provisions of NFPA 90A, Standard for the Installation of Air Conditioning and Ventilating Systems. 3.1 1.2 No heater employing an open flame or glowing element will be installed in helicopter hangar bay areas. 3.1 1.3 Heating systems fired with gas, liquid, or solid fuels whic
36、h serve aircraft maintenance and storage areas will be located in a detached building or in a room separated from the hangar by minimum 1 -hour fire-rated construction. 3.12 Electrical Systems. 3.12.1 Electrical services will be installed in accordance with Article 5 13 of NFPA 70, National Electric
37、al Code. 3.12.2 Floor grounding receptacles will be provided for removal of static electrical accumulations on aircraft while aircraft are stored or undergoing servicing inside the facility. 3.13 Fire Protection Systems and Equipment. 3.13.1 Automatic sprinkler protection, consisting of one of the f
38、ollowing types of systems, will be provided in helicopter hangar bays in accordance with the requirements specified in this ETL: a. Wet-pipe foam-water systems utilizing aqueous film-forming foam (AFFF). b. Preaction foam-water systems utilizing AFFF. c. Water-only wet-pipe systems utilizing Early S
39、uppression Fast Response (ESFR) sprinklers operating at a minimum discharge pressure of 345 kPa (50 psi). 3.1 3.2 Conventional automatic sprinkler protection, utilizing water (only j and standard sprinklers, will be provided for offices, shops, storage and similar areas adjoining or adjacent to heli
40、copter hangar bays. Hazard classifications and corresponding sprinkler design requirements will be in accordance with MIL-HDBK-1 008C. 3.13.3 Manual fire alarm (evacuation) systems will be provided in accordance with NFPA 72, National Fire Alarm Code. B-3 Provided by IHSNot for ResaleNo reproduction
41、 or networking permitted without license from IHS-,-,-3535789 0814824 291 = ETL 11 10-3-485 15 Oct 97 3.13.4 Portable fire extinguishers will be provided in accordance with NFPA 1 O, Portable Fire Extinguishers. Wheeled extinguishers employing potassium bicarbonate dry chemical are generally recomme
42、nded for helicopter hangar bays because they provide the maximum extinguishing capability for Classes B and C type fires. 4. SPRINKLER PROTECTION FOR HANGAR BAYS 4.1 System Types. 4.1.1 Sprinkler systems will be closed-head type. Deluge (open-head) systems will not be used. 4.1.2 Systems will be foa
43、m-water type using AFFF unless conditions specified herein can be met to permit water-only wet-pipe systems using ESFR sprinklers. 4.1.3 Although foam-water sprinkler systems using AFFF generally provide optimum effectiveness in combating a combustible or flammable liquid spill fire, water-only syst
44、ems using ESFR sprinklers are considered to be an acceptable alternative. 4.2 System Selection. 4.2.1. The following guidelines for selecting the type of system to be used in helicopter hangar bays are based upon the presumption that heating systems will be provided where required to preclude freezi
45、ng of pipes during winter months. 4.2.1.1 In geographic areas having a 99% dry bulb temperature greater than - 1 O “C (1 5 OF), wet- pipe sprinkler systems will be used. 4.2.1.2 In geographic areas having a 99% dry bulb temperature between -18 OC (O OF) and -10 OC (1 5 OF), either wet-pipe or preact
46、ion system may be used. Selection of system type will be based upon local factors that can affect potential for freezing of wet-pipe systems. 4.2.1.3 In geographic areas having a 99% dry bulb temperature of less than -1 8 “C (O OF), sprinkler systems will be preaction type using AFFF foam-water solu
47、tion. 4.3 Foam-Water Sprinkler Systems. 4.3.1 Except as modified herein, foam-water sprinkler systems will comply with applicable provisions of ETL 1 1 10-3-484, Aircraft Hangar Fire Protection Systems, for detailed requirements for foam-water sprinkler systems. 4.3.2 Foam-water sprinkler systems wi
48、ll be either wet-pipe or preaction type. B -4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3515789 0834825 028 ETL 1 1 10-3-485 15 Oct 97 4.3.3 The floor area covered by an individual foam-water sprinkler system in helicopter hangar bays will not
49、exceed 1393 m2 (1 5,000 fi). 4.3.4 Sprinkler systems will be hydraulically designed to provide a uniform minimum discharge density of 6.52 liters/min/m2 (O. 16 gpm/ft2) over the hydraulically most demanding 1 1 15 m2 (i 2,000 fi) of floor area. 4.3.5 The maximum allowable protection area of coverage for a sprinkler will be 12.1 m2 (130 fi). 4.3.6 The distance between sprinkler
