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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Fire Safety => Topic started by: kpnut on May 14, 2007, 12:18:08 PM
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Inlight of the excellent advice received previously - could anyone please advise on the following:
The distance required for vehicle access to the mains inlet is 18m - no specific distance is mentioned from the mains inlet to the fire fighting shaft - Am I correct in thinking this can be as far away as it wants to be even though the fire fighters have to lug all their equipment with them ?
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Good question kpnut.
Yes I think you are correct in that approved document B or BS5588 dont state any distances for this. I know Herfordshire did some research into the time taken to attack the fire where dry mains are remote from the shaft and found in such cases it was much quicker to use conventional hose rather than mess with the dry main.
The main should comply with the new BS9990 and I believe there is some concern over possible horizontal extensions between the main and the shaft- I dont yet have a final copy of this BS so hope someone else can clarify.
I recall a piece in a recent Fire Engineers Journal on this topic- I think it was written from a very one sided (Fire service) viewpoint though and ignored many of the huge advantages of dry mains even if they cannot be conveniently routed through a building.
As a cynic I am amazed at the recent turnround in ADB and the need for the developer to provide private hydrants and static tanks here there and everywhere, when brigades have been avoiding their responsibilities under the former 1947 Act for years.
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kpnut,
Although no minimum horizontal distance is laid down for the distance between the inlet and the outlet, the design still has to meet the functional requirements of B5, 'reasonable facilities to assist firefighters in the protection of life'. I would ask the local FRS for a decision on what they consider to be reasonable.
Your unlikely to get a uniform answer nationwide since a lot of that reasonableness will depend on the resources available to the FRS in that area.
As Kurnal says, empirical evidence would suggest that the time of attack on a fire from arrival on site can easily be doubled but that is largely dependent on the distance from the appliance, number of floors, distance to the hydrant.
Dry rising mains have their place in building design however they are not the panacea that some would believe them to be.
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remember that the corridor leading to the stair should have the same level of fire protection as the stair itself. That probably means lobby protection from any accomodation. This usually makes long corridors too much of an inconvenience.
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Thats right Wee B. I am working on a project at the moment where just such a corridor has been rejected by the developer, and the only alternative is to put the access door to one of the firefighting shafts on the opposite side of the building to the fire main inlet serving the shaft.
Cant see any other way in this case but not looking forward to hearing the comments of the BCO or the Brigade.
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A neighbour of mine is involved in the scouting and guiding movement. They have a site which is used for camping and the movement have decided to demolish the existing facilities and build new to accommodate a more modern structure with better facilities including those for the disabled. They have applied correctly for permission to build and the local Brigade has bounced the application as they cannot get a fire appliance closer than 50 metres to the perimeter fence, exactly as it is now. They have no room for manoeurve as the land is not owned by them and the lane to be driven down is unmade and narrows with no scope to increase the width. Therefore on the strength of this consultation, the Brigade have effectively shut down a facility for children. If anyone has any ides that could be useful, I would welcome their comments.
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A bit of publicity should do the trick.
Jobs worth fire service close down important youth facility. Likely increase in ASBOs as result.
"Kids will have to hang about on streets instead"- CFO.
Firefighters unable to run out more than two lengths of hose anymore..........
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In August 1995 I visited the 'Leisure World' complex at Hemel Hempstead as it was being completed. I recall that this has two corridors into the complex to form protected escape routes and they are also fitted with horizontal 'dry risers' so that the F&RS has 'bridgeheads' inside the building. I do not have any notes as to the length of these dry risers. The building is partly fitted with sprinklers for property protection as well.
Re the scout hut problem raised by Jokar - I would agree with kurnal on publicising this decision. I can see two possible solutions, perhaps, in addition.
(a) Install a 'horizontal' dry riser from the nearest point reached by appliances using buried plastic piping;
(b) Consider a sprinkler installation as a school might have?
But this cannot be the only such location in the county concerned with such limited access. Don't the F&RS covering the area have suitable means of dealing with such places? Either L4Ps or at least an L4V could be made part of the first attendence?
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Is the access 50 metres short of the perimeter to the site or to the buildings?
Possibly the buildings could be relocated in a different area? Still at planning I presume.
Sprinklers would be good, in a remote location such as this seems to be the likelihood is that the buildings would be lost if a fire were to occur.
On the subject of 4 wd, my earlier comment on reasonableness may largely be determined by available resources of the FRS your dealing with. I don't think that there are that many services outside of the largely rural ones that have small 4wd vehicles with pumps etc.
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In addition it seems that the fire service through their comments are only trying to make things better than they previously were in relation to a fire occurring in the premises and the resolution of any incidents that may occur. I sometimes get the feeling from some contributors on this site that the FRS are perceived to be determined to stop everybody from doing anything just to be difficult.
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Thanks for the comments thus far. It is an existing site with existing facilities. All that is being undertaken is an upgrade to the facilities. As the early post mentioned, the group have no rights to upgrade the access and that would probably include the digging of a trench to lay a main. If a fire occurred today the FRS would have the same problem with the access. I understand the thought of an FRS attemptong to make things better but for those of us who have done it, a couple of lengths of hose is not a lot. The location of this semi rural place, probably a 20 minute drive on the bell would ensure that any fire is well developed by the time the FRS arrive, if it is the local appliance of course, and protection would be the key. Sprinklers seem to be a large hammer to crack a small nut but it will be a consideration. An FRA would indicate that the ignition sources inside are minimal, brand new electrics, no smoking and no naked flames. Of course we have a possibility of an outside fire but staff are trained by the local Brigade in FFE and they test the equipment as well.
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I know some BCO's/FIO's (including myself)have taken the view that,where a similar building/home is replacing an existing,as the situation 'is no worse' it would be unreasonable to insist on all the trappings of 'B5' e.g. upgrading of a long unmade/ or narrow track etc, and a recommendation would be made that a domestic sprinkler system is installed instead.This of course would not be the answer in all cases.
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Inlight of the excellent advice received previously - could anyone please advise on the following:
The distance required for vehicle access to the mains inlet is 18m - no specific distance is mentioned from the mains inlet to the fire fighting shaft - Am I correct in thinking this can be as far away as it wants to be even though the fire fighters have to lug all their equipment with them ?
I posted this on the other thread-but BS5588-11 para 40 on will give more info:
It can get quite complex,as there are possibly two issues here-the 'inlet' could in theory be remote from the shaft/entrance to the building (although as mentioned earlier it has to be hydraulicly sustainable to meet the BS requirements)-but as there is likely to be multi pump attendance,this is not necerssarily an issue (i.e. one pump deals with suppling the water,another gets personnel & kit up the FF shaft.)Lets keep it simple though and assume that it is a dry mains,inlet situated near to the FF shaft-then BS5588 Part 11 (para 40.5.2)says that the max distance between Outlet at highest level and fire appliance is 30m-but only 'horizontal' travel distance has to be counted if there is a FF lift.If there is no FF lift,then both horizontal and vertical distance counted,with the stair sections multiplied by 150%.
BS5588 Part 5 will give some other examples,depending on type of use of building/number of floors,but for instance, access to a FF shaft,that is not on an outside wall,should be via a protected route and no longer than 18m.
So yes,there is a maximum distance that a FF should be expected to lug his gear,and I wish someone had told me that many years ago,as a proby I had to lug B.A.,FF equipment and two lengths of hose up 11 storeys once-and it was no Fun!
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Thanks Pip thats useful information.
Aint it strange though- I have the latest version of 5588 part 5 and it is far less explicit and quite different to the para from part 11 that you have quoted. I cant understand why only 5588 part 11 contains this info- compare it for example to 5588 part 1 para 34.
Hydraulically the horizontal pipe runs in a steel fire main would be far less significant than the pressure loss due to head or indeed the losses when compared to fire service delivery hose.
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Just taken a further look at BS5588 part 11 para 40 and figure 20.
I cant figure it out at all. It seems to be telling me that the total distance from the appliance to the highest dry main outlet is 30m and if I dont have a firefighting lift I must add 50% to the vertical distance travelled up stairs.
So if my building is 18m high the vertical element up the stairs will take 27m out of my total 30 m allowance so if the firefighting shaft contains no horizontal pipe at all the inlet has to be within 3 m of the appliance parking position. If theres any horizontal pipe at all we have had it.
Or putting it another way according to figure 20 if the appliance can only get to within 18m of the main inlet the maximum height of the building will be 8m.
Please tell me what I am missing here ?
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kurnal
Forgot to add the dry riser main should be 4ins in diameter
Conqueror
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Just taken a further look at BS5588 part 11 para 40 and figure 20.
I cant figure it out at all. It seems to be telling me that the total distance from the appliance to the highest dry main outlet is 30m and if I dont have a firefighting lift I must add 50% to the vertical distance travelled up stairs.
So if my building is 18m high the vertical element up the stairs will take 27m out of my total 30 m allowance so if the firefighting shaft contains no horizontal pipe at all the inlet has to be within 3 m of the appliance parking position. If theres any horizontal pipe at all we have had it.
Or putting it another way according to figure 20 if the appliance can only get to within 18m of the main inlet the maximum height of the building will be 8m.
Please tell me what I am missing here ?
Yeah,strange that these requirements are not in B5 or BS5588 part 5. No I don't think you are missing anything (or maybe we both are!).As you know, a building over 18m would need a FF lift&Shaft+fire mains-so that building of yours, to comply,would need to allow the Fire appliance to reach within 3m of the entrance-remember 18m is a maximum distance.I would suggest that that requirement has been missed on a lot of builds ie you will find 18m + 27m!
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Yes I was going to say 17.9m in the post but it looked a bit messy.
I am suggesting that its the recommendation in part 11 that is wrong, not the buildings. Its just totally impractical- like the requirement for isolating valves every 10m in BS9990.
You know we just cant move town centres, water main infrastructure and natural ground contours around to meet the quirks of the the various BS committees, Functional requirements have got to be the way forward rather than prescriptive standards.
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Jokar,
Have you considered using a horizontal main, it will not overcome the issue of the FRS having to carry their gear, but it should demonstrate a genuine attempt to assist the fire service in ensuring the water supply reaches the building.
As Pip says under Building Regulations you could use the "no worse than existing" argument although I have no doubt that this would be included as a planning condition if the FRS wanted to dig their heels in.
As for the discussion on distances from inlets to the FFS, this was a topic that was discussed at the seminars that the DCLG held for ADB2006, where it was said that this factor was becoming an issue for the FRS when carrying equipment and discussions should be undertaken with the FRS to discuss any issues where horizontal extensions of mains were adopted (Although it was obviously not serious enough to incorporate within the Approved Document itself!!!)
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Im not convinced that a horizontal dry main would be of any great advantage here.
It will need an inlet and an outlet both of which will need to be checked before being safe to charge.
Presumably this will involve opening some kind of enclosure to access the inlet and outlet.
The pump crew will have to run out and connect a length of hose to the inlet (25m roll of hose) and carry a coiled 25m length of hose to the outlet, unroll and connect before tackling the fire. (then go and look for a hydrant to supplement the tank supply)
If the appliance is 50m away from the site entrance this is just two lengths of hose. So wheres the saving in time and effort? It will be quicker to run out hose direct from pump to the fire.
In the days when I first joined the service there were regular hose running competitions, the two man hydrant drill (to ship a standpipe, run out the hose,connect the branch and give water on) was regularly completed in well under 10 seconds with one length of hose, and with two lengths around 12 seconds.
Compare that to locating the inlet and opening it, locate the outlet and open it (you may be close to the fire at this stage with no working equipment) running hose from pump to inlet, carrying coiled hose to outlet, run out hose and couple branch remember all dry and in the proximity of the fire unless you run back towards the fire appliance.
The other alternative of providing a wet hydrant at the building itself will be of little benefit as it is most unusual for the firefighters to run a jet direct from the hydrant without using the pump to control the flow.
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All,
Thanks for your contributions. The person concerned is no farther forward at this moment but has set up a tri parthied meeting with the BCO and the FRS to try to gain a resolution.
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Just an update on this, the FRS have come back with Residential Sprinklers as a must because of the extra 5 metres involved. At least with the provison of these the shower block may be still standing when the brigade get there!!!