- Author
- Back, G. G., III | Darwin, R. L. | Sheffey, J. L. | Williams, F. W.
- Title
- Propellant Fires in a Simulated Shipboard Compartment: Project HULVUL. Phase 3. Final Report.
- Coporate
- Hughes Associates, Inc., Baltimore, MD Naval Research Laboratory, Washington, DC
- Report
- NRL/MR/6180-99-8394; Final Report, August 20, 1999, 41 p.
- Keywords
- shipboard fires | ships | propellants | flashover | compartment fires | burning rate | ignition
- Abstract
- On 17 May 1987, the USS STARK was struck by two Exocet missiles while streaming in the Persian Gulf. In addition to blast and fragment damage, the ship experienced a major conflagration, initiated by the warhead detonation and the burning of the remaining solid rocket propellant. In response to this incident, the Chief of Naval Operations (CNO) and the Naval Sea Systems Command (NAVSEA) launched the Internal Ship Conflagration Control Program (ISCC) to evaluate and develop new capabilities (doctrine, procedures and equipment) for controlling interior ship conflagrations. The ISCC programs included numerous compartment fire investigations using conventional fuels and a multiple phase investigation into quantifying the thermal insult produced by the burning of the unexpended propellant (Hull Vulnerability (HULVUL)). The results of the three HULVUL test series support the same conclusions on the period during and shortly after the missile impacts the ship. These conclusions only apply to solid propellants that contain their own oxidizer(s). The burning of the missile propellant produces a high intensity short duration thermal exposure in the space which should last for a period of approximately one minute. Although the conditions in the space would technically meet the definition of flashover (upper layer temperatures on the order of 500 deg C-6OO deg C), these conditions are only sustained until the missile propellant is consumed. The lack of oxygen in the compartment during the missile fuel burning stage delays the ignition and sustained burning of the Class A materials in the space. The ignition of these materials was shown to be related to the ventilation conditions in the space but could not be quantified due to scatter in the test data. Based on these results, it should be assumed that ignition can occur and potentially transition into a fully developed compartment fire, but no faster than the normal growth of class A fire. The resulting compartment fire characteristics will be a function of the compartment geometry, ventilation conditions in the space, the quantity and surface area of the fuel, and are beyond the scope of this discussion. Independent of these conditions, there should be a period of greater than five minutes after the missile impacts the ship where flashover conditions are not yet achieved to initiate firefighting procedures. Once initiated, the success of the firefighting effort then becomes a function of the ability to access the compartment and the equipment and tactics used to combat the fire.