Rank: Super forum user
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A question for the fire risk assessors out there
Lift truck and battery charger unit, what is the appropriate distance so as to prevent the ignition of two distinct types if materials?
May be some one who considers some of us as doom and gloom merchants would care to answer first?
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Rank: Super forum user
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Well I am no expert but I would suggest that many things can go wrong when BC a FL. Hydrogen gas from batteries and sparks generally do not mix very well and garage workshops / warehouses can have many combustibles in close proximity to the unit and FL. I would suggest a specific area away from any operational activity, preferably with fire resistant shielding / walls to prevent / reduce spread. I have seen/used moveable FR 1200 x 2400 wall units to segregate welding activities and BC. Good ventilation and SSOW and electrical maintenance schedules are also essential. I was in the garage trade for 12 years and did warehouse management for 5 years and saw many fire risk scenarios presented by poorly maintained battery charging units and bad practise. I would need to do some research regarding the actual safe ignition distances as there are many variables to consider but personally at short notice I would suggest around 3 to 5 metres.
Shoot me down then…
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Rank: Super forum user
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Distances seem appropriate, cheers.
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Rank: Super forum user
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In all cases i have seen the forklift and charger are right next to each other i certainly haven't seen many cases of them being 3-5 mtrs apart. My thought would be that you would need a source of ignition to combust the flammable gasses. with this in mind i would have thought charges would have been designed to contain any possible sources of ignition. also the connection and dis-connection procedure i would have thought would be important either by switching the power off before connecting or disconnecting.
Now days the connection between the charger and FL are moulded plugs i would have thought these might be designed to contain any spark when disconnecting the two. i think main consideration would be local ventilation and control of other equipment with in the area that might cause and ignition source. At my old company we had massive high level bay forklift these would be impossible to contain in a purpose built area not just because of their size but the number we had and the difficulty in manoeuvring such large pieces of equipment close enough into one area. However we did have very good extraction system in the area
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Rank: Super forum user
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Phil - I think the original question was asking about the separataion distance between the charger and other combustibles in the area rather than the charger and the truck. So for example in a warehouse, how far is your high bay truck charging point from the rack full of cardboard boxes filled with polystyrene granules...
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Rank: Super forum user
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Thanks Heather I thought the way the question and previous answer was worded we where talking about the forklift and the charger and flammable gases.
I guess the only consideration with the charger and nearby combustible materials would be if the charger put out and source of heat. never touched the side of a charger myself but i wouldn't have thought they would give out a great deal of heat? certainly no more than a domestic oven and we house these in a wooden box and seem to be able to sleep easy at night certainly covering up any vents like and electrical piece of equipment is going to cause issue. maybe checking the temperature when they are charging would help give and safe distance if it's needed.
Hopefully given the right answer to the right question this time.
Phil
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Rank: Super forum user
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Hi Phil,
The scenario in question is where a lift truck is fully involved in fire due to electrical fault at the charging unit and not the hazard of overheating.
We are looking at an approprate separation distance to reduce/prevent the risk of ignition of other combustible materials stored in the same area.
The distance selected would be based on
Conservative heat release from an electric truck involved in fire 1500- 2000 kW
Combustion energy lost by flame as radiation (%) 60%
Radiant heat required to ignite thermally thin materials 10 kW/m^2
Radiant heat required to ignite thermally thick materials 20 kW/m^2
Separation distance required : 2.2 - 3.2 metres.
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Rank: Super forum user
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I'm certainly not going to argue with your numbers Bleve. Why i think it is great in calculating these figure isn't enforcing them unrealistic or we are certainly looking at an idealistic world. I'm sure you as i have that people in the average work place do the most stupidest of things when it comes to fire safety with out a thought.
So not sure how you would looking at ensuring that calculations you have come up with would be enforced. i guess marking out the floor or some other might be one way to go but i think the management of the premises could easily ruin any good system put in place by yourself.
i guess if you can get a system in place at the start and have the right people in place to maintain it then i guess anything is possible. i would settle for employees not constantly blocking fire exit doors for the management to actually maintain the equipment on site i guess they have to start somewhere.
Red
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Rank: Super forum user
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True Phil,
But fire risk assessment or fire safety should also take into account property protection in addition to life safety. Fire also has serious consequences even where fatality or injury does not take place.
Unfortunately, the vast majority of EU legislation is concerened only with life safety and we could definately learn something from other legislation elsewhere in the world.
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Rank: Super forum user
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"But fire risk assessment or fire safety should also take into account property protection in addition to life safety. Fire also has serious consequences even where fatality or injury does not take place"
Quite true. The leaning towards fatality only FRAs is quite wrong.
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Rank: Super forum user
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I think the fact that so many companies are failing to look after life safety means that property protection doesn't even exist to these people. hopefully life and property protection will become built in during the construction stage as certainly most new premises have built in fire detection and emergency lighting which wasn't the case a few years ago. Also with Wales making mandatory to install domestic sprinkler systems hopefully this will be adopted to other high risk premises (schools hospitals sheltered housing)
Phil
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Rank: Super forum user
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Rank: Super forum user
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Drifting off the original question, attempt to get back to it - I just looked through the guide to fra's in factories and warehouses, not too many mentions of flt's but the main one states "fork lift truck charging points should be carefully sited in a well ventilated area (ideally direct to open air), clear of ignition sources and preferably in a separate dedicated non-combustible structure. However, if sited in the building, the charging point should be against a fire-resisting wall (e.g. 30 minute fire resistance).
Sparks and hydrogen are also mentioned briefly.
My question - is this as far as we need to go as that's all the guide states?
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Rank: Super forum user
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Unless the charger is in a very small room, with a very low ceiling, no or very little ventilation coupled with prolonged charging then the issue of hydrogen gas, ignition and secondary ignition of other fuels is highly unlikeley. In fact I would go so far as to say it would not be possible to ignite other fuels following the ignition of what hydrogen had accumulated.
The guidance documents and the RR(FS) O require that the risk of fire based consider the presence of fuel and ignition sources.
Chargers & FLT's have been involved in fires and as such the must provide radiative and convective heat to their surroundings. Separation by distance reduces or eliminates this risk.
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Rank: Super forum user
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The guidance document states the minimum that would be acceptable or should be done. certainly adding in maintenance and inspection of the equipment would also have it's part in preventing fire starting in the first place. Sometime reading the guidance documents it's surprising at times how little is expected. Luckily modern day building regs are forcing that standard a lot higher.
Phil
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Rank: Super forum user
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Let us not forget that adherence to the requirements of a guidance document means nowt and provides no protection in law
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Rank: Guest
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Bleve
I work for a major UK insurer. For property protection requirements a 2m clear distance is considered good practice.
This guidance is available:
Fire Protection Association - RC11 Recommendations for the use of fork – lift trucks.
Paul
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Rank: Super forum user
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bleve wrote:Let us not forget that adherence to the requirements of a guidance document means nowt and provides no protection in law
Why do HSE and other 'organisations such as Her Majesty's Government publish so many apparently useless guidance documents then?
Perhaps our tory / lib dem friends should stop all funding to HSE, Emergency Response, LAs, and the DCLGP as there publications mean 'nowt'.
Quite a remarkable statement!
Gidday,
GC
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Rank: Super forum user
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Oh whoopy! :-)
Forklifts and fire, two of my favourite subjects!
Another thing to consider is the number and size of the batteries and (as somebody has already highlighted) the size of the space and air movement. Some of the warehouses I have worked in before have had charging areas servicing a dozen or more FLT's at once, each with spare/swapable battery packs. In these cases the batteries were charged under extraction hoods.
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