Re: Fire Extinguishers
Posted by: (---.dyn.iinet.net.au)
Date: January 19, 2008 10:01PM
Apart from avoidance, having a fire extinguisher on board is best option,
Halon is illegal, with substantial fines possible for release, interestingly enough, halon is still legal for aircraft.
That aside, what are the options available,
Firstly there is a water extinguisher, good for carbonacous fires (wood, paper, plastics) now on a Loco there is a substantial amount of wood, but the size of extinguiher would preclude its use anyway, however a good hosing can be very effective, as water will cool, smother, protect the person fighting the fire and is (usually) readily available and cheap.
Option 2 would be a dry powder, essentially baking soda, these come in 2 types, the variation being (a) price and (b) the contents, the 2 points being linked, the more expensive ones have a triple named powder which is slightly better at putting out a wider range of fires, it "interfers with the chemical reaction", separating the fuel from the oxygen, excellent "knock down" performance in that it works very fast, but the fire is subject to reignition if the powder clears, as the ingredients for a fire, heat, fuel and oxygen will still be present, I agree that the powder gets EVERYWHERE and is a bugger to remove, but for sheer size, portability, effectiveness, price and availability mean that this is the extinguisher of choice for most vehicle applications.
They are 1 use only, but as they are cheap this is ok.
I carry 1 on the car and 1 in my back up vehicle/trailer,in fact at the price they are worth having in all vehicles, old and new.
The powder will "settle" and compact over time, but this can be remedied by inverting the extinguisher once a month, -also a good time to check the gauge to ensure it is still in the "green" area
Other options are indeed foam, which is only detergent and water and the foam is created by venturi action when the extinguisher is operated,
This is a particularly good extinguisher in that it can be used to PREVENT a fire, (note that in the recent plane crash at Hethrow, they doused the plane with foam in case of a spark)
so in thecase of fuel spraying all under/around your car you could happily empty aa foam extinguisher over it and be confident of preventing a disaster,
If used to extinguisher, they are best for liquid fires, not spraying into the fuel, but layering a blanket over the fuel to smother it, this blanket will generally stay intact for 15 or 20 minutes, enough time for you to do someting more permanent.
Unfortunately size again usually would prevent you carrying on aboard your steamer as they, like water come in 9 litre sized extinguishers (minimum), howver there is a lot of merit in keeping on in the garage and or the trailer
CO2 is another option, possibly an alternative to powder, as it will not gum up anything, can be supplied in quite small cylinders and will work effectively over a range of fires, but... (always a but!)
the gas is a quite high pressure, meaning that the cylinder is very sturdy (read heavy) and they discharge very quickly and the CO2 is heavier than air and will blow away very easily making their use on the road limited, The gas as it discharges is very cold and MAY damage through clod cracking, but again a good case can be made for having one handy in the workshop/garage
There are other whizz bang ones, but cost is often prohibitive,
For my money, keep a dry powder on the car, a spare in the trailer, and if really keen a foam one in the trailer as well.
hope this enlightens.