Fire service measures
and in all of these cases, the fires were very intense.
Piled waste tests
The piled test of wood (see Figure 8 below) presumed that the provisions of the WISH Guidance 1 regarding fi re resistant separation had been applied. The confi guration used presents some key challenges for fi refi ghting crews compared to an open pile of material, as follows: 1. The material is only accessible from one side and therefore all fi refi ghting operations must be undertaken from this elevation.
2. The material displays a high degree of water resistance.
3. The volume of material involved, which will require the use of heavy plant to aid in the excavation of the pile to expose the core of the fi re (see Figure 9 below).
Two bays were fi lled with 17 tonnes of RDF and ignited by the application of an oxypropane lance fl ame, directed to the middle of the pile through a 1.5m section of stainless steel pipe with a 100mm diameter.
Application of the ignition source in this
way helps simulate ignition of a deep seated fi re, and a full justifi cation for this method will be included in a thesis that will be submitted in support of a PhD to be completed by 2020. The test method provided a good correlation to data obtained from real fire data. Both RDF fires were ignited at the same time as
baled plastic was ignited. Both were allowed to develop for 48 hours and were monitored using thermocouples buried throughout the mass of the piled waste and thermal imaging cameras. Both fires developed significant anaerobic pyrolising cores, with temperatures recorded between 400°C and 500°C. Waste fires have apparent similarities to coal seam fi re behaviour in this respect. Eventually, the surface of both of the RDF
fires was ignited manually, approximately 52 hours after initial ignition, as neither fire had breached the surface as expected. The surface fi res were then allowed to develop for two hours prior to the fi re extinguishing test.
Extinguishing methods
Water test Water jets were applied to the surface fi re, and it was noted that application of the medium had a good knock down effect. However, water did not have any impact on the temperature reading obtained from the thermocouple 1m below the surface, and the application of copious amounts of water did not appear to have any impact on the water’s ability to penetrate the pile; the water merely ran off.
Wet Class A compressed air foam system (CAFS) The foam solution applied to the RDF fi re was noted to have displayed a similar ability to knock down the fl ames; however, with CAFS, it was also noted that the temperature was reduced 1m below the surface of the fi re, showing a degree of penetration. Again, the application of copious quantities of foam did not show any better performance, and just contributed to runoff. Foam however displayed a degree of
resistance to burn back not displayed by water.
FOCUS
www.frmjournal.com NOVEMBER 2018
27
Figures 8 and 9 (left and right)
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60
