Fire alarm call points

[Mushy]

Hi all

I think that BS 5839 states that Fire Alarm Call Pointsshould be 1.4 metres from the ground...give or take 0.2 m...is this hard and fast or just a guideline?

Does anyone know any other specifications for call points..I've read two different distances 30m and 45m to travel to one and 25m in high risk areas...I don't have a copy of BS 5839 to hand.

Thanks

[nearlythere]

Hi all

I think that BS 5839 states that Fire Alarm Call Pointsshould be 1.4 metres from the ground...give or take 0.2 m...is this hard and fast or just a guideline?

Does anyone know any other specifications for call points..I've read two different distances 30m and 45m to travel to one and 25m in high risk areas...I don't have a copy of BS 5839 to hand.

Thanks

Mushy. All British Standards are guidelines other than when legislation says they must be complied with.

[Phoenix]

You should try to put them at the recommended height because that is where people expect to see them generally, but if you have good reason to put one at a different height then fit it as appropriate for the risk.  This is a case where a sign might be useful to help locate it.  Try to avoid having it two inches or twelve feet from the ground.

Stu

[Wiz]

Hi Mushy, I basically agree with nearlythere regarding recommendation/guideline bit.

In repsect of travel distances:
The BS figure is 45m actual travel distance or a 30m 'straight line' distance where the actual travel distance is not known at design stage. The 45m and 30m distances are reduced to 25m and 16m respectively where there are a significant number of occupants with limited mobility and it can reasonably anticipated that one of these occupants will be the appropriate person to first operate the mcp.

mcps should also be sited in close proximity of equipment or activities of high fire hazard level.

[David Rooney]

Hi all

I think that BS 5839 states that Fire Alarm Call Pointsshould be 1.4 metres from the ground...give or take 0.2 m...is this hard and fast or just a guideline?

Does anyone know any other specifications for call points..I've read two different distances 30m and 45m to travel to one and 25m in high risk areas...I don't have a copy of BS 5839 to hand.

Thanks

The travel distance to reach a call point was increased from 30m to 45m but is still subject to RA depending if the occupants are trainee olympic sprinters or a wheelchair basketball team.

So technically call points can be 90m apart..!

The 30m bit comes into it when your looking at plans and drawings and in theory if you have a straight line of 30m between call points then you are going to be within the 45m travel distance rule....

clear as mud !!??


 

[Dragonmaster]

The BS also recommends the locations for CPs but you wouldn't want one by the front door of the local where the naughty people can activate it after a guiness or 6. Again back to the FRA and what is reasonably practicable.

[Owen66]

Wouldn't Part M of the building regulations suggest that MCP's are mounted at 1200mm AFFL rather than 1400mmAFFL ( a fact recognised in BS 5839.1 in AMD 1)

Note 5 and 6 to Clause 20.2 (h)

NOTE 5 The measurement should be made between the finished floor level and the centre point of the frangible element.
NOTE 6 The figure of 1.4 m is arbitrary, but reflects long established custom and practice. A minor difference
(e.g. less than 200 mm) in mounting height (e.g. to align with the mounting height of light switches) need not be regarded as significant, nor need it be recorded as a variation.

Regards

Owen

[jokar]

As does part 6.

[mevans421]

Hi Mushy

At a huge cost to myself I have a copy of BS5839-1 in front of me.

Height of 1.4 metres is a figure established from long established custom and practice.  A variation of no more than 200mm can be undertaken and is useful for alignment with light switches and in particular is a good height for wheelchair users.  If the +/- 200mm range is used then it is not regarded as significant and does not need to be recorded as a variation on the relevant design paperwork.

The distance of 45 metres is the maximum distance anyone should have to take along a route to get to a point - that is round obstacles etc.  This is going to be difficult for the designer to know at the design stage, but maybe something that the installer makes the designer aware of and certainly the commissioner.

Therefore, if at the design stage the final layout of the premises is unknown then the designer should allow only 30 metres in his drawings.  This is expected to catch more or less all of the final distances not being in excess of 45metres once furniture and fittings are in place.  Again these distances are arbitary.

The above distances should be shortened to 25metres where a significant number of people are likley to be mobility impaired and shortened again to 16 metres if processess in the area are likley to result in rapid fire spread in the event of ignition.

Where there is a specific hazard such as a kitchen or other high risk area then a MCP should be located in its immediate vicinity.

Hope this helps

[Wiz]

Hi Mushy

At a huge cost to myself I have a copy of BS5839-1 in front of me.

Height of 1.4 metres is a figure established from long established custom and practice.  A variation of no more than 200mm can be undertaken and is useful for alignment with light switches and in particular is a good height for wheelchair users.  If the +/- 200mm range is used then it is not regarded as significant and does not need to be recorded as a variation on the relevant design paperwork.

The distance of 45 metres is the maximum distance anyone should have to take along a route to get to a point - that is round obstacles etc.  This is going to be difficult for the designer to know at the design stage, but maybe something that the installer makes the designer aware of and certainly the commissioner.

Therefore, if at the design stage the final layout of the premises is unknown then the designer should allow only 30 metres in his drawings.  This is expected to catch more or less all of the final distances not being in excess of 45metres once furniture and fittings are in place.  Again these distances are arbitary.

The above distances should be shortened to 25metres where a significant number of people are likley to be mobility impaired and shortened again to 16 metres if processess in the area are likley to result in rapid fire spread in the event of ignition .

Where there is a specific hazard such as a kitchen or other high risk area then a MCP should be located in its immediate vicinity.

Hope this helps

Mevans 421, this is basically just as I confirmed earlier today.

Normally, I wouldn't comment on such - I think repeating the same thing reinforces it and maybe gives confidence that the advice is correct.

However, there is a minor point in your post that I think needs clarification. I have highlighted it in bold in the quote box above.

In my understanding of the BS the 16m distance has nothing to do with if processess in the area are likley to result in rapid fire spread in the event of ignition but is the corresponding reduction in the 25m distance as the 30m is to the 45m (that you correctly explain).

I welcome your comments if you disagree with my understanding.

Wiz

[mevans421]

Hi Wiz

I quote:

BS5839-1, clause 20.2. e. The figures of 45metres and 30 metres quoted in d) should be reduced to 25m and 16m respectively in th following circumstances:
1) where a significant proportion of occupants have limited mobility and it can reasonably be anticipated that one of these occupatns will be the appropriate person to first operater the fire alarm system in the event of fire; or
2) where processes in the area result in the liklihood of rapid fire development (e.g. where there is use, of processing, of highly flammable liquids of flammable gases).

I think that clarifies

Now I'm off for some shut eye - check in tomorrow.   

[colin todd]

The distance is not really based on a risk assessment as has been suggested, and the difference between travel distance and direct distance is one of the most basic principles of means of escape, where it has been used for decades. The changes made to BS 5839-1 were to line up means of escape and fire alarm, so that people stopped the silly habit of putting a call point at 30m and another one at the exit door a few metres further on. And the 200m leeway was precisely to help disabled people without the need for even a variation.

[Wiz]

Hi Wiz

I quote:

BS5839-1, clause 20.2. e. The figures of 45metres and 30 metres quoted in d) should be reduced to 25m and 16m respectively in th following circumstances:
1) where a significant proportion of occupants have limited mobility and it can reasonably be anticipated that one of these occupatns will be the appropriate person to first operater the fire alarm system in the event of fire; or
2) where processes in the area result in the liklihood of rapid fire development (e.g. where there is use, of processing, of highly flammable liquids of flammable gases).

I think that clarifies

Now I'm off for some shut eye - check in tomorrow.   

mevans421, you are correct about part 2) of your explanation. I never had my BS with me and I was quoting from memory and I forgot about the second sub-clause. it is included along with the 'limited mobility' reasons as a need to reduce travel distances.

However, I still think your original explanation could be misunderstood. I read your original post to mean that distances are always reduced to 16m for the reasons of the second sub-clause.

I quote the part of your post that says this:

The above distances should be shortened to 25metres where a significant number of people are likley to be mobility impaired and shortened again to 16 metres if processess in the area are likley to result in rapid fire spread in the event of ignition.

This is not how I read the BS.

My undersatnding is it needs to be reduced (for both reasons) to only 25m if the actual travel distance can be calculated and to 16m 'straight line distance' if it can't be pre-calculated (at design stage).

I'm off to earn some money - check in later 

[nearlythere]

The distance is not really based on a risk assessment as has been suggested, and the difference between travel distance and direct distance is one of the most basic principles of means of escape, where it has been used for decades.

A good example of this in practice is probably, but not necessarily, in University Avenue, Belfast. If you take the direct distance between a well used watering hole on one side of the street and the chippy opposite and called it X. To find the travel distance/time one must multiply that by A + 1 - 24 to reflect  the time of day, B + 1 - 12 to reflect the numers of sticky green drinks taken and C + 1 - 200 the traffic conditons at the time.
So at around 1am on a Sunday morning, with 14 of the said drinks taken and in light traffic conditions one could, if leaning slightly forward and tie at 90 degrees, make it across the road, with legs flailing in all directions, in around half of the direct distance time.

[Mushy]

Thanks all for taking the time to reply, it is appreciated.

A hospital is in the process of changing the entire fire alarm system, including call points. These new call points have been positioned lower than the original ones...just at the right height for hot locks (meal trolleys) and other medical containers to wallop them off the wall or smash the glass....something that has happened recently. They could of course go for a variation and put on protective hinged flaps which will obviously mean two actions to operate....and probably will do.

The design practicioner has said that the reason they are lower is because of the DDA so as to accommodate wheelchair users. I suppose they have done this with the plus or minus 0.2m that is mentioned in the BS (thanks nearlythere)