FOCUS
Time for a rethink? Stewart Kidd explores portable extinguisher types and questions whether watermist units should be considered more going forward
sector could usefully reconsider the way in which portable fi re extinguishers are provided in cultural resources/buildings. In that article, I quoted from research which suggested that water was the most suitable fi refi ghting agent for these premises. This article takes the debate forward, and asks whether we should not give thought to the wider problems of fi refi ghting by occupants of workplaces.
I
N A previous article in this magazine (‘Overlooked asset’, FRM November 2017, pp30-35), I suggested that the heritage
Corridor engine 48 NOVEMBER 2018
www.frmjournal.com
I also reviewed the history of the way the occupants of large country houses fought fi res after portable fi re extinguishers were invented in England in 1818. These were not used in any great number until further refi nement in the 1880s. Before this, most fi res were tackled with a combination of hand pumps and buckets. While siphon type extinguishers had been in use in Roman times, the earliest type of self contained portable was the soda acid water extinguisher, which operated when a small container of sodium bicarbonate was dumped into the body of the extinguisher – this was fi lled with a mixture of water and (usually) sulphuric acid. The resultant reaction produces carbon dioxide, which then expels the water. Such a unit was patented in 1881 in France. Soda acid units were used in large numbers in all types of workplaces until the 1960s, when the wider availability of small carbon dioxide cartridges provided a safer, alternative propellant. Stored pressure units using nitrogen are now the most common type of portable, and the same method of propelling the firefighting agent is in common use with foam, powder and wet chemical portables. The earlier foam units operated when a solution of sodium bicarbonate was mixed
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
