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How to Quantify Fire Brigade Intervention

One of the most commonly asked questions we get as fire engineers is:

"Will the South Australian Metropolitan/Country Fire Service accept this Performance Solution?"

Don't know what a Performance Solution is? Check this post.

fire engineering truck

This is a loaded question and the answer can be quite complex but for South Australia it all starts with an answer to a very simple question:

Does the matter need fire brigade consultation?

This is generally a call made by the appointed Building Certifier and there are typically two camps when it comes to answering this:

  • Yes. Any Performance Solution relating to fire and life safety will have an impact on firefighting operations and referral to the fire brigade is required or;

  • Only if the matter is directly related to firefighting such as fire hydrants, automatic fire sprinklers and smoke hazard management.

If given the choice, fire engineers normally opt for the former option as it gives the South Australian Metropolitan Fire Service (SAMFS) or Country Fire Service (CFS) the opportunity to review the Performance Solutions and decide if it is relevant to their operations.

Once it's been established that SAMFS/CFS require consultation and the consultation/PBDB process is followed as per this post, the next task for our fire engineering team is determining the impact the proposed solution has to firefighting operations.

Fire Brigade Intervention Model (FBIM)

For some Performance Solutions, the fire brigade may feel comfortable with the provisions discussed during the consultation meeting and provide approval in-principle which is recorded in the meeting minutes and referred to in the Fire Engineering Report (FER).

In other situations, it may be necessary to quantify what impact the proposed Performance Solution has on the time required by the fire brigade to respond to a fire. Fortunately, the Australasian Fire Authorities Council (AFAC) developed a method to do just that called the Fire Brigade Intervention Model (FBIM).

The FBIM uses what's known as an event-based methodology to calculate the time from fire brigade notification of the fire all the way through to control and extinguishment. This is a tool for fire engineers accepted widely across the industry.

When to Use FBIM?

The most common application of FBIM in fire engineering analyses is in absolute and deterministic approaches whereby the total time from ignition to application of water on fire is presented to the fire brigade for review and approval against their operational expectations.

The most common Performance Solution it is associated with is when additional hydrant hose lengths are proposed for full coverage. i.e. it is used to show the additional time and effort required to set up the extra hose length does not result in an adverse time impact on operations.

Using FBIM

The FBIM has evolved over a number of revisions with improving levels of statistical data and helpful documentation. The latest edition at the time of writing is version 3.0 comprising the below documents:

Using FBIM is very straightforward and is effectively just using flow charts with the supplied datasets to calculate a time associated with each of the following categories:

  • Time to fire brigade notification

  • Time to dispatch resources

  • Time to reach kerb side

  • Time to assess and access fire

  • Time to travel to set up area

  • Firefighter travel rates

  • Time for water set up

  • Time for search and rescue

  • Time for other property protection

  • Time to control and extinguish the fire

  • Time for environment protection

There is some science and engineering involved in calculating the times associated with each of these categories (some tasks may be undertaken in parallel of one another) and it is beyond the scope of this post to cover the technicalities. Fire engineers have to keep some trade secrets to keep their doors open.

Worked Chart Example

As a simple example though, let's consider Chart 1 (time to fire brigade notification) on a hypothetical building with the following fire safety systems:

  • Automatic fire detection system which detects fire up to 60 seconds after ignition

  • No automatic fire sprinkler system

  • Alarm Signaling Equipment (ASE) connected to SAMFS/CFS

Our fire engineering team would arrange Chart 1 as follows.

Fire engineers model
fire safety engineer table

Although a simplified example, it conveys the simplification of a complex process that is fire brigade response into a series of logical steps. Once the relevant charts are completed, the time can be displayed graphically. An example is shown below.

Fire engineers graph


The FBIM serves as another tool in the arsenal of skilled fire engineers in their efforts to demonstrate that compliance with the Performance Requirements may be achieved through non-standard means.

If you're interested in learning more about how our team of fire engineering experts can assist with your next project involving fire brigade intervention, please reach out and contact us.


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