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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Operational => Topic started by: kurnal on April 15, 2014, 10:19:38 PM
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I was looking at ADB and in particular diagram 49- Relationship between building and hardstanding / access roads for high reach fire appliances.
Dimension A is the MAXIMUM distance of the NEAR EDGE of the hard standing from building. For a TL the MAXIMUM distance is 4.9m. For an HP the MAXIMUM distance is 2.0m.
Thinking about how these appliances operate should these not be MINIMUM distances? The appliances would be very restricted in their range of movement if operated from a position immediately adjacent to the building. Or am I missing something?
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You need to bear in mind that these appliance need to put down jacks to increase the stability of the appliance when operating the aerial part. Its something to do with the center of gravity and all that technical stuff.
The other aspect is the out reach of the business end of the equipment. TLs have a longer reach because they can extend the ladder in a straight line, whilst hydraulic platforms are limited by the length of the upper boom(s) which in turn is limited by the length of the actual vehicle.
The closer you can get to the building the greater area on the face of the building you can reach without repositioning the appliance, therefore in theory the more windows you can reach to effect rescue or entry.
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I was looking at ADB and in particular diagram 49- Relationship between building and hardstanding / access roads for high reach fire appliances.
Dimension A is the MAXIMUM distance of the NEAR EDGE of the hard standing from building. For a TL the MAXIMUM distance is 4.9m. For an HP the MAXIMUM distance is 2.0m.
Thinking about how these appliances operate should these not be MINIMUM distances? The appliances would be very restricted in their range of movement if operated from a position immediately adjacent to the building. Or am I missing something?
Get your point K. Also the projection is dependant on the jacks being at their maximum extension.
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The reason I asked was because I was looking at an old fire brigade document that predated the 1991 Building Regs and gave these dimensions as MINIMUM distances and wondered who was right.
There was an old National document widely used before the 1991 ADB that I have been trying to trace if anyone can help.
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Could it be Home Office fire prevention note 1/1970 Access for fire appliances, but unfortunately I do not have a copy.
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Thanks Tom of course it was. Now the challenge is to find a copy! I have one somewhere.....
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I think Maximum is correct. If you're worried about an appliance being too close to the building then dimension C (which is a minimum) is the one that takes care of that and allows appliances to be parked a suitable distance from the building.
If dimension A were a minimum then there would be nothing to stop the hardstanding being 20 or 30m from the building!
Stu
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Thanks Stu. Yes I take your point and the diagram is an illustration of a typical situation, I am still curious to compare the ADB with the old Home Office fire prevention note 1/1970 Access for fire appliances if anyone can help out.
The diagram is more appropriate to rescues from windows rather than use of aerial monitors as it does not take account of roof overhangs within dimension A or C.
For large storage buildings where access is required to 100% of the perimeter for high reach appliances I tend to focus more on the potential reach of the aerial monitor rather than the position of the appliance. To me that's what Functional Requirements are all about.
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It seems to me that the issue is about the capability. If you need to get the aerial appliance that close to a building for rescue from windows you will need the hard-standing available. If you are looking at large storage buildings and you need the monitor capability then the hard-standing can be extended away from the building.
The major issue comes when you have a building where you may need the ability to get an aerial close to effect rescues and the designers and architects start pointing to ADB and saying 'it doesn't say that in the document'. Unfortunately the majority of architects have no idea about the practicalities of fire fighting and stick to the guides.
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To be fair to architects, most firefighters don't know much about desiging buildings.
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True, but architects don't have to put the things out!