Aim: Fire extinguishing foam is usually combined with sea water during firefighting operations on a ship or at a seaport. The structure of sea water is different from fresh water. Sea water contains large quantities of mineral salts, which may cause the deterioration of extinguishing foam and consequently reduce the effectiveness of firefighting. For this reason foam intended for use in conjunction with sea water should contain a higher resistance to the high concentration of electrolytes contained in salt water. The purpose of this paper is to compare the suitability of testing methods for foam used in firefighting, which is mixed with sea water.
Project and methods: This research project utilised the most commonly used methods in Europe for testing firefighting foam, which is mixed with sea water, specified in standards; PN-EN 1568, ISO 7203-1, ISO 7203-3 and regulations from the International Maritime Organisation (IMO). The article reveals results from investigations dealing with foam quality for three synthetic foaming agents (S1, S2 and S3) and one fluoroprotein foam concentrate (FP4). Tests focussed on; foam creation, expansion ratio and drainage velocity, and extinguishing effectiveness. Two foaming agents (S1 and S3) can be mixed with freshwater only. Other agents (S2 and FP4) can be mixed with both, freshwater and sea water.
Results: Tests, of agents intended to be mixed with fresh water as well as those designed for mixing with sea water confirmed an inferior production of foam, with a lower expansion ratio and reduced foam stability, for concentrates formulated with the use of sea water. Achievement of the flow rate identified in IMO regulations was more difficult during tests. However, a simultaneous application of three nozzles and an increase in the delivery intensity significantly increased the effectiveness of extinguishing operations and allowed for quick and successful extinguishing of test fires.
Conclusions: The quality of extinguishing agents used during fire incidents has a large bearing on the effectiveness of firefighting. During operations at sea ports, extinguishing agents’ resistance to influences of sea water is of particular importance. An agent, of appropriate quality and suitably applied increases the safety of people and mitigates the economic as well as ecological losses attributable to fires.
Keywords: firefighting foam, sea water, fire and rescue operations
Type of article: original scientific article