Different Ways to Fight Fire
The Canadian Fire Insurance Grading Index is being expanded to include information on alternative water supply systems. Here's what you need to know to rate a risk not protected by traditional fire hydrants.
But what does it really mean? Do these fire departments actually have the ability to deliver enough water to fight fires successfully?
To answer these questions, we must look at how all public fire protection water supply systems are measured. The fire insurance grading process is complex and measures fire suppression capacity across many variables; however, each measurement is completed as a percentage of available credit. The maximum available credit for any item graded represents the most resources that would be used in combatting a fully involved structure fire. As such, the first measurement that is taken is the risk present, or the required fire flow (rate and duration of water need to control fire) of a building or group of buildings.
Once the required fire flow is established, we then know how many resources will be needed, and at what times they will be needed. With respect to water supplies, knowing the required fire flow (in conjunction with domestic demand) helps designers to know how large to make pipes, pumps and reservoirs to ensure that there will be adequate water supply for fire fighting. However, as communities (incorporated and unincorporated) are not required by law to meet any specific standard for water supplies for public fire protection, each community decides for itself to what extent it will provide water for fire fighting. This is one of the most important reasons that the insurance community in Canada formed the Fire Underwriters Survey organization, to measure fire protection levels against insurance industry benchmarks in a standardized way for the Canadian insurance community.
How the Grading System Works
The fire insurance grade system measures the ability of the community to deliver the required fire flows during maximum daily domestic consumption. In each area of the grading, the measurement is taken as a percentage. For example, if the required fire flow is 2,000 Igpm (Imperial gallons per minute), then a community that can provide 1,000 Igpm at that location (in the specified time frame) would receive 50% credit. Typically, the minimum fire flow to be recognized for fire insurance grading in any area is 10% credit. With respect to water supplies for public fire protection, the minimum amount of water required to be recognized is:
- 200 Igpm (one hose stream) with a two-hour duration for personal lines (must be able to deliver at adequate nozzle pressure at a distance of 300m from the hydrant),
- 400 Igpm (two hose streams) with a one-hour duration for commercial lines (must be able to deliver at adequate nozzle pressure at a distance of 180m from the hydrant).
Traditionally, water supplies for public fire protection were recognized when delivered through a system of pipes and hydrants. However, it is also possible to deliver the same amounts of water in the same time frames reliably and systemically without hydrants. This process is called “alternative water supply for public fire protection.”
Types of Alternative Water Supply
There are two main types of alternative water supply systems currently in use in Canada that are being evaluated for the purposes of fire insurance grading:
- Superior Tanker Shuttle Service (STSS)
- Large Diameter Hose Lay (LDHL)
The systems can be used independently, or in conjunction with one another. A third system currently being evaluated involves using fireboats as mobile hydrants in conjunction with land-side fire fighting to produce fire flows.
Fire Underwriters Survey worked extensively with a committee formed with the Canadian Association of Fire Chiefs to develop a protocol for the delivery and accreditation of alternative water supplies for public fire protection.
When considering how to treat alternative water supply systems such as STSS, it is important to know that, to be accredited, the fire department need only provide the minimum amount of water that is required of a hydrant system (as opposed to the required fire flow). As such, it is important for insurers and brokers to know the amount of water that can be delivered through the accredited system. The Canadian Fire Insurance Grading Index is being expanded to include this information, so that insurers and brokers can make informed choices.
Hydrant coverage is limited to 300m for dwellings and 150m for commercial lines insured buildings. This restriction is derived from the number of hydraulic losses associated with delivering water through hose at those lengths, as well as the amount of hose carried on fire trucks and the minimum amount of residual pressure required in the supply system, along with several additional factors.
Similarly, fire hall coverage is limited to 8km by road from fire halls due to the rapid decrease in the chances of saving property after structure fires reach flashover.
Alternative water supply systems also have specific limitations. Superior Tanker Shuttle Service (STSS) is applicable only in areas that are within 8km by road of an accredited fire hall, and within 5km by road of a recognized water supply point. Large Diameter Hose Lay (LDHL) is applicable only in areas that are within 8km by road of an accredited fire hall, and within 600m of a recognized hydrant.
As the areas where fire insurance grades are intended to be applied have become increasingly complex, Fire Underwriters Survey has developed a set of digital geographic information system (GIS) maps that show specifically where accredited alternative water supply services, such as STSS and LDHL, apply. These maps can be accessed through the online Canadian Fire Insurance Grading Index, and they are address searchable.
Underwriters across Canada have responded extremely positively to the STSS coverage maps, and Fire Underwriters Survey is now in the process of creating fire insurance grade maps for all areas of Canada that will be address searchable, and will include details like hydrant coverage and applicable grades for each area.
Are the Alternatives Equivalent to Hydrants?
Alternative water supply delivery requirements are identical to hydrant system delivery requirements. The fire department must demonstrate, through documentation and testing, that it can deliver a specific amount of water in the same time frame as it would if using hydrants, reliably, and at a rate that meets or exceeds the minimum requirements for hydrants.
The important thing to remember is that being recognized as a water supply delivery system for fire insurance grading purposes does not mean that the system can provide the required fire flows reliably and redundantly. It only means that the system exceeds the minimum requirements. This is true of hydrant systems, as well as alternative systems. To assist insurers in understanding the capacity of the water delivery systems, the Canadian Fire Insurance Grading Index will be expanded to show the relative classifications of the water supply system, which is a true measure of the water system’s capacity to deliver required fire flows (with a layer of redundancy).
Fire Underwriters Survey encourages insurers and brokers to recognize accredited alternative water supplies in the same way they recognize hydranted water supplies. However, in both cases, the rate reductions associated with this level of protection should be correlated to the quality of the system relative to the risk, as opposed to being a binary recognition—i.e., protected or unprotected.
Any water supply system, alternative or hydranted, can be a critical factor in successful fire fighting when adequate resources are available at the right times to deliver the water supplies. Whether fire departments utilize traditional hydrant systems or STSS systems, they can substantially improve the chance of saving property during fires.
Michael Currie, GiFireE, AScT, is national technical director for Fire Underwriters Survey. He can be reached at firstname.lastname@example.org.
Copyright 2014 Rogers Publishing Ltd. This article first appeared in the March 2014 edition of Canadian Insurance Top Broker magazine