Main inlet location

[Martin Burford]

kurnal
Forgot to add the dry riser main should be 4ins in diameter
Conqueror

[Pip]

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!

[kurnal]

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.

[saddlers]

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!!!)

[kurnal]

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.

[jokar]

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.

[jokar]

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!!!