Bomb Alerts

[Davo]

We have a Training School with ten storey resi block, new Gent fire alarm fitted.
Our Estates are wanting to use it for a two tone fire/bomb alert and rip out the antiquated tannoy system.
I'm not convinced the students/visitors will be able to tell the difference, probably some of the staff too.

I can't find any guidance, BS etc on the subject

Advice please!


davo

[Chris Houston]

Generally, if a bomb were discovered in a building, you would want people to act differently from how they would in a fire. 

So fire alarms are not really suitable for bomb alerts.

However, the first issue I'd be tackling would be - do you need a bomb alert system.  I would suggest that for the most part, most people don't.  How many bombs or even suspected bombs do they have per year?

[Midland Retty]

If you look at the BS it doesnt forbid a fire alarm having dual roles, so long as the purpose of the alarm is to signal an evacuation.

So its not a blanket "no" that you cant use the fire alarm system to evacuate people in the event of a bomb alert. If the prime purpose is to evacuate the building (whether because of a fire, bomb, or other emergency) you can use the fire alarm system to do that.

I seem to remember that some explosive devices could be activated or triggered by the activation of a nearby electrical impulse or electrical devices and Ive seen some bomb evacuation policies which discourage activation of the fire alarm in case it sets of the bomb. How true that is in reality Im not sure.

Also depending on the nature of the bomb threat you may not want to instigate an out and out evacaution, or rush of people en mass, there may instead be other more appropriate procedures to follow

[Chris Houston]

I think most of the bombs the UK has suffered from were activated by timer or by manual activation.  I don't think one being operated by nearby electrical impulses has ever been used and if it were, there would be plenty other systems with higher voltages than fire alarms (for example lighting, and power supplied to IT). 

I think the risk of a bomb attack for most UK buildings is tiny and the risk of a bomb using this technology is close to zero.

If we start having systems in place in case of bomb, we should also probably be having systems in place to deal with all other risks of the same magnitude, elephant stampedes, tsunami, volcanic eruption, alien landing, vampire attack..........

[Davo]

Chris

We have to have them because of who we are (P*od) and our location.
As for alien landing, I think you will find all govt/councils/999 have an Op Order dealing with this eventuality


davo

[Midland Retty]

I think most of the bombs the UK has suffered from were activated by timer or by manual activation.  I don't think one being operated by nearby electrical impulses has ever been used and if it were, there would be plenty other systems with higher voltages than fire alarms (for example lighting, and power supplied to IT). 

I think the risk of a bomb attack for most UK buildings is tiny and the risk of a bomb using this technology is close to zero.

If we start having systems in place in case of bomb, we should also probably be having systems in place to deal with all other risks of the same magnitude, elephant stampedes, tsunami, volcanic eruption, alien landing, vampire attack..........

Think I may be getting mixed up... there was something about fire alarms and the potential for them to activate bombs.

Perhaps it was vibration caused by sound pressure levels from fire alarm sounders inadvertently activating the device prematurely. I certainly wasnt suggesting the fire alarm system acted deliberately as the intended fuse!!!.

Anyway it matters not. The point as you said Chris is that it would pointless whacking in one system to cover one eventuality, such as a bomb scare, another system for to cover another eventuality large emergency etc etc.

This I probably why the British Standard allows the for fire alarm system to be used for general evacuation purposes as well as fire evacuation.

I disagree slightly Chris with your statement that if you have a system in place to deal with bombs threats you should have systems in place with elephant stampededs et al.

Some buildings do get regular bomb threats. Police stations, universities, airports, animal testing facilities, to name a few can get scares on a regular basis, so it is perfectly reasonable to expect them to have some form of procedures in place to deal with them.

[rn976]

Davo

The Home office did publish a guide on bomb threats, I will have dig around and see if I can find it. Other things to think about, would be your evac point whilst this may be a place of total safety from fire with flying glass etc or secondary devices outside your premises you may be putting them into danger, prehaps in a protected internal stairway is a good holding point?,  good secuirty can stop the internal device but with evacuation for a threat to a large outside car park for example, it is easy to place the bomb here. (I belive Bali is an example of this)   
Another good source of info would be to contact your local police, they where running training around the UK called project Argus with the National Counter Terrorism Secuity Office, on just these issues.

Hope this helps

rn976   

[nearlythere]

The important thing about bomb alerts is to know where the suspect device is or is suppose to be and what exits would be affected.
Absolutely no point using an audible fire alarm to evacuate the building if everybody exits towards the location of the device.
Apart from a means of warning other factors relating to the building layout would need to be considered.
Alternative MOE and a safe and speedy route away from building and vicinity without being exposed to effects of detonation.

[kurnal]

Yes I agree with NT and others. The strategy is different. Fire is a known hazard, the alarm identifies its location and everybody moves away from the known location to a place of ultimate safety. 

No alarm system can predict where a bomb might be sited, in one infamous terrorist attack on an army camp the terrorists found out where the assembly point was, telephoned in a bomb threat causing the evacuation of the buildings to the assembly point in the car park. The terrorists had actually sited the bomb in the car park for maximum effect. 

So in my view the fire alarm system is too inflexible, you will have intelligence and the fire alarm system does not allow you to apply this intelligence.

On the other hand if your alarm is latest Gents kit some of the sounders  (eg the S Quad range of multi sensor detector heads incorporating sounders) can be configured to give different tones and even pre-recorded voice messages and so for certain types of event a different signal can be generated. Now this you could use - fire having one tone, bomb threat stay put and be vigilant another tone, bomb threat evacuate plan 1, bomb threat evacate plan 2 could also have seperate tones.   

But I bet you havn't put your hand deep enough in your pocket to buy the S Quads!

[Clevelandfire 3]

Im sorry Kurnal you reply is quite inaccurate for several reasons.

Firstly a fire alarm doesnt always know where a hazard is. Im amazed you actually said that.

An effective bomb threat evacuation procedure should firstly involve the determination and desemation of information relating to the threat. For instance a telephone call: " Ive planted a bomb in the third floor gents bogs" is a sepcific threat which can be checked and verified. Is it a hoax? From that you decide whether or not to evacuate. If you decide to evacuate why cant the fire alarm be used to signal the an evacuation?

Next " there is a bomb on campus" . This is non specific threat , and the bomb could be anywhere. You certainly dont start evacuating people yet. Again you wonder if its a hox, you ask the caller question to try and find out where the device is. If that fails you try and do a quick search to identify any suspicious items on evacuation routes and assembly points, you dont just evac everyone. Once you are happy the bomb isnt near the "assembly point" or evacuation routes you then initiate an evacuation. They cant stay in the building indefinately. Also with bomb threats you dont use normal assembly points like a fire evacuation instead you should marshall people well away form the building to specific points often a few streets away.The locations are unknown by most members of staff / public for the reason that the bombers may have sabotaged the assembly points. Plus  no method of evcaution can rule out the possiblilty the assembly points have been nobbled. It wouldnt matter if you verbally asked people to evacuate or set of the fire alarm in that respect, so I dont get your point there either  Kurnal. As nearlythere says you check exits. You put people in place to direct people away from sabotaged routes before evcuation.

Mildand Retty is correct that 5839 permits fire alarms to be used for other evacuation purposes so never rule it out as an option, may save time. And Retty you werent wrong about concerns fire alarms possibly setting off bombs, This was a widley held belief years back, since dispelled as a myth, or unrealistic danger. The police used to adviuseagainst use of the fiore alarm for that reason.

[nearlythere]

Nobody goes to verify if a bomb is genuine or not C3, other than the army. Bombs, other than incendary devices, are not generally taken into a building and they can be detonated by tampering - this to try and catch out ATO's and delay defusing.
Also much safer and quicker for a terrorist to use a car bomb outside a building.

The fact that a warning is received would indicate that the intention is to cause structural damage without injury to persons and usually there is time to evacuate.

Following 9/11 the new breed of terrorist can be a different animal who prefers to cause death and injury on a grand scale. The media exposure of just causing disruption to daily life and damaging a few buildings is of little significance to this type and warnings may be not be so forthcoming.

It would not be considered good working practice for employers to nominate employees to carry out checks on suspect devices.

[kurnal]

Cleveland like many of my postings my answer to Davo is probably full of errors and mistakes. If asked I offer my opinion with no guarantees and no liability. I believe most internet forums are like that.

I dont think Davo was actually asking for our advice on how to manage a bomb threat.  I am sure he has access to more experts on that topic than we could dream of and I am sure he will be seeking their advice on the subject as well. But I think he was interested in our views on the dual use of the fire alarm specifically for this purpose.

My opinion is that the latest technology may have new features that support alternative uses of fire alarm systems using voice messages and coded alternative tones.

Whether this is any use or not depends on its flexibility to repond to the information received - for a particular cause or warning will the pre-configured alarm system produce the desired effect in getting people to a place of safety appropriate in the circumstances.

 In this respect a tannoy system is far superior.

[nearlythere]

Correct Kurnal
You can make more definitive plans and procedures for fire emergencies than bomb alerts. There is much that can be done to detect fires and protect escape routes. There is precious little that can be done to detect and protect escape routes from the effects of bomb detonations.
It is very important to have more control over a bomb evacuation than a fire. During a fire evacuation most people may not know where the fire would be and may, whilst proceeding to an exit, happen upon a block escape route and can take a safe alternative.
In a bomb situation it is important to help ensure that evacuation does not exposed people to a greater danger by escaping towards the bomb. A bell, siren or clanger only gives a general warning of danger and does not give specific instructions on the safest escape route.
If someone calls in a warning and says there is a bomb in the building then you can only do what you can under the circumstances. You cannot hold people at their place of work whilst you search for a bomb and it may need to be evacuation by wing and a prayer.
However, if someone calls in a warning saying there is a bomb in a car at the front of the building then steps can be taken to reduce exposure to the device.

[Midland Retty]

I have too disagree with much of what has been said in relation to bomb evacuations. But this is going off topic somewhat.

Davo asked if the fire alarm can be used to signal other evacuations. The simpe answer is yes....with a very big "BUT"!!

Some bomb threat procedures allow for people to evacuate after intial inspections are undertaken to ensure escape routes are safe, so there is no reason why the fire alarm couldnt be used.

After all the fire alarm tells people to get out of the building, and in some cases its better that staff arent told there is a bomb threat, but are just informed to get out of the building.

Thats no different to a tanoy system, or security staff wandering round telling people to quietly evacuate.

Clearly in the scenairo Davo gives,for police officers the procedures to be followed will be highly detailed.

[Chris Houston]

Nobody goes to verify if a bomb is genuine or not C3, other than the army.

Sorry to disagree.  But it should be staff who do the search.  The searchers need to be the people who work there normally and should be familiar with the area.  Army bomb experts won't know what is our of place in a work place.  Naturally, you can't force people to do this task and it will fall to volunteers.

http://www.cpni.gov.uk/SecurityPlanning/searchPlanning.aspx