- Author
-
Marker, T. R.
|
Diaz, R.
- Title
- Oxygen Enhanced Fires in LD-3 Cargo Containers.
- Coporate
- Federal Aviation Administration, Atlantic City International Airport, NJ
- Sponsor
- Department of Transportation, Washington, DC
- Report
-
DOT/FAA/AR-TN98/29
May 1999
14 p.
- Distribution
- AVAILABLE FROM: Federal Aviation Administration William J. Hughes Technical Center's Fire Safety Section's Full-Text technical reports page (in Adobe Acrobat portable document format [PDF]): http//www.fire.tc.faa.gov/reports/report.stm AVAILABLE FROM National Technical Information Service (NTIS), Technology Administration, U.S. Department of Commerce, Springfield, VA 22161. Telephone: 1-800-553-6847 or 703-605-6000; Fax: 703-605-6900. Website: http://www.ntis.gov
- Keywords
-
oxygen
|
fire tests
|
fire suppression
|
smoldering
|
halon 1301
|
inerting
|
temperature
|
toxic gases
|
halons
- Identifiers
- deep-seated cargo fire; LD-3 cargo container; oxygen-fed fire
- Abstract
- Since the fatal ValuJet in-flight fire accident on May 11, 1996, attributed to the improper shipment of chemical oxygen generators, the shipment of oxidizers and pressurized oxygen has been restricted. In early 1998, at Public Hearings convened by the Research and Special Programs Administration (RSPA), interested parties proposed that the transport of pressurized and medical oxygen cylinders be permitted in cargo compartments protected with fire detection and suppression systems (Class C cargo compartments). During the meeting it became apparent that appropriate test data did not exist regarding the performance, of oxygen cylinder overpacks in cargo compartments. Consequently, the FAA committed to performing two different test protocols. One protocol entitled "Oxygen Enhanced Fires in LD-3 Cargo Containers" demonstrated the inadequacy of the LD-3 cargo container in controlling the spread of an oxygen fed fire. The second test protocol entitled "Evaluation of Oxygen Cylinder Over-Packs Exposed to Elevated Temperature" evaluated the performance of various cylinder overpacks to determine whether a specially designed overpack would prevent a cylinder from overheating and releasing the oxygen into the cargo bin, thus creating a catastrophic fire. Two series of tests were undertaken to examine the fire safety aspects of pressurized oxygen cylinders involved in a cargo compartment fire suppressed with Halon 1301. In the first test series, oxygen cylinders were subjected to a furnace temperature of 400 deg F, which corresponds to the level possible during a suppressed cargo fire. When the surface temperature of the cylinder reached approximately 300 deg F, which occurred rather quickly, the pressure relief disc failed and discharged the cylinder contents. In the second test series, the oxygen cylinder quantities measured during the initial test series were introduced in a deep-seated cargo fire being suppressed with halon inside an LD-3 cargo container. The results were influenced by such factors as the amount of oxygen discharge, the spacing of the stowed cargo, and the location of the oxygen discharge point relative to the initial fire. In one test involving the release of 22 cubic feet of oxygen, the initial discharge of oxygen caused a violent combustion reaction, which partially separated the front surface of the container and enveloped the periphery of the container in flames. By the end of the test. the fire had destroyed the container. The results point to the need for oxygen cylinder shipping containers that are suitably designed for thermal protection against a cargo fire.