The Gledhill Study

J B Gledhill, Tasmania Fire Service

AN ABSTRACT

In January 1998 on the urban/rural interface of Hobart, Tasmania experienced one of its most potentially damaging bushfires. Over a 24-hour period, 1,000 houses on the interface were directly threatened by a bushfire burning through a drought-affected eucalypt forest under severe fire weather conditions.

In accordance with Tasmania Fire Service policy, residents were advised through the media to remain with their homes during the fire. There were no deaths or serious injuries, and only seven houses and a number of outbuildings were destroyed. Of the houses lost, six were unoccupied.

Following the fire, investigations showed the majority of residents heeded the advice to stay and were successful in protecting themselves and their properties. Most Australian fire services have advocated this approach for many years. It is supported by conclusive research findings in respect of the causes and circumstances surrounding the loss of lives and the destruction of buildings during a number of major bushfire events in Australia during the last 30 years. Where adequate fire protection measures have been implemented, able-bodied people remaining with a house are able to extinguish small fires as they start. Houses also provide a safe haven from the sometimes very high levels of radiant heat which may occur.

Bushfires will inevitably continue to occur, and we must learn to live with them. Vulnerable communities, if properly prepared and empowered, can be effectively and safely involved in their own protection. Death, injury and property damage can be significantly reduced.

Like much of Australia--particularly the southeastern and southwestern corners--Tasmania is prone to bushfires. Similar to many other places in the world, the interface communities living on the fringe of the bushland and urban areas are highly susceptible to death and damage from bushfires. Tasmania has not suffered large-scale damage since February 7, 1967, when one of Australia's worst fire disasters occurred. In about five hours, fires in the south of the state consumed around 250,000 hectares (600,000 acres) of forest and farmland, killed 62 people and tens of thousands of livestock ,and destroyed 1,300 houses and numerous other buildings.

In February 1983, similarly devastating bushfires occurred across the southeastern mainland states of South Australia and Victoria, this time causing 76 deaths and destroying 2,463 houses--lessons learnt from past bushfiresIn the wake of these fires and a number of others, Australia's principal scientific research organization--the Commonwealth Scientific and Industrial Research organization (CSIRO)--universities and fire services have undertaken research into how and why houses are ignited and subsequently destroyed in bushfires in Australia. These investigations, conducted immediately following each major fire event, study the circumstances surrounding the loss of houses in relation to type of construction, building materials, siting, mechanisms of ignition and destruction and effectiveness of intervention. One of the principal researchers is Dr. Caird Ramsay who, with his co-workers, has conclusively found that the dominant mechanism of ignition of houses is by airborne embers entering buildings or landing on vulnerable parts of buildings. In a minority of cases the ignition source is direct flame contact and radiant heat usually from vegetation burning in close proximity to the building.

Damage by wind accompanying the fire is also common. Wind has been found to cause direct damage to buildings by, for example, removing roof cladding or blowing in windows, and indirectly, by blowing tree branches or other items into windows causing them to break. In either case, wind can breach the integrity of buildings, giving access to burning embers.

Accounts of spontaneously exploding houses are discounted. Strong evidence suggests that ignition usually occurs through wind-borne embers starting a small fire or fires on or in a combustible part of the building. These small fires may grow relatively slowly or unnoticed at first. Once the inside of the building is alight the fire may continue to burn slowly, pre-heating the inside and contents until a window breaks, or the fire breaks through to the outside, venting the fire and resulting in very rapid or almost explosive combustion. Frequently, the ambient weather conditions speed the rate of destruction. During the time between the spot fire ignition and the rapid destruction phase, there is usually opportunity for successful intervention by vigilant people with simple firefighting tools such as a wet mop and bucket of water. The majority of houses lost, almost regardless of their construction, are unoccupied at the time of the fire passage. Many houses burn down up to three hours after the fire front passes. Of the houses that survive, the majority are protected through the actions of people, either the occupants, neighbors or fire brigades. These people are able to take action, often just by extinguishing the very small fires started by airborne sparks and embers.

The flammability of construction materials does have an influence, but this is effectively reduced because in Australia high flammability products such as timber shakes and shingles and bituminised roofing are not usually permitted to be used for any residential purposes. As would be expected, masonry provides the best protection. Research has revealed radiant heat to be the biggest cause of death. Caught in the open, people are extremely susceptible to radiant heat and are rapidly overcome by heat stress. Solid surfaces provide the best protection from radiant heat, and one of the best is sheltering in buildings. Houses do not explode, and even during the passage of the main fire front, unprotected houses will provide a safe haven during its passage and the period fishiest radiant heat.

Many people who perish in Australia during bushfires do so trying to escape. Frequently they are caught on roads blocked by fallen trees or power lines. In other cases they crash because of smoke or panic, or both. Evacuation is frequently left until the last possible moment ,and then it can be too late. People commonly try to take with them all that is precious, taking too long to pack it into their vehicle or having to find pets before leaving.

The prepare, stay and survive strategy

The research findings into how houses catch alight during bushfires have lead most Australian fire agencies to now advocate, where adequate fire protection measures have been taken, able-bodied people should remain with their houses when threatened with bushfires.

Tasmania Fire Service (TFS) has supported this position for a number of years, but until January 1998 had not clearly articulated its position with respect to evacuation. A position paper was drafted in January, only days before a major bushfire invaded the urban/bush interface of Hobart. The Tasmania Fire Service and Tasmania Police Position on Evacuation and Protection of People and Property Endangered by Bushfires, is believed to be unique within Australia. Whilst most fire services support a similar strategy, formal agreements with their police services have not been achieved. Adequate preparation is essential for bushfire survival. People living in an urban interface area (and anywhere else where buildings are located adjacent to or in the bush) are advised to undertake fire protection measures to reduce their vulnerability to bushfires. These measures include removing, or at least modifying or reducing, flammable vegetation fuels around buildings--mowing grass, raking up leaves, bark and other fine fuel vegetation debris, and removing flammable understorey plants. Trees, even eucalypts, can remain, as they do not constitute a fire hazard without understorey fuels. A 'defendable space' of very low and discontinuous fuel,or preferably no fuel, needs to be created around buildings. If fuels are minimized or removed in the surrounding immediate area (say 20 metres) the fire intensity (or the ability to burn at all) will be reduced,along with the radiation and ability for direct flame contact on the building. For buildings situated on steep vegetated slopes, the distance of fuel reduced will normally need to significantly extend downslope from the building. Vegetation type and slope angle are used determine safe distances.

House design and maintenance need to be taken into account. Spaces and gaps which could allow wind-driven embers to lodge should be minimized, as should combustible horizontal or sloping surfaces such as timber decks and verandahs. Roof guttering (spouting) should be maintained in a clean condition. For those situations surrounded by tall eucalypts, this is an ongoing regular task.

An adequate water supply, and firefighting tools such as a pump and hose, are normally recommended for rural areas. In the suburbs on the fringe they are probably not essential. Simple firefighting tools such as buckets of water, wet mops and knapsack pump garden sprayers should be readily available.

TFS and most other Australian fire services recommend attention be paid to all the potential ways of improving the safety performance of buildings and their surrounds. This multi-faceted approach will optimize the resistance of a building to bushfires and provide, as a consequence, a safe haven for its residents. Where people have undertaken these fire protection measures, in accordance with our position, TFS advises able-bodied people to remain with their houses during bushfires. The very young--say those less than 10 years old--and aged or handicapped people, should leave early as possible, as a minimum, at least 30 minutes before the fire is expected. The people remaining need to dress appropriately and be prepared to undertake simple firefighting activities.

People who have not taken adequate measures are advised not to stay. Where a house does not have sufficient defendable space and access to water supplies, the chances of saving it are greatly reduced and the danger for remaining occupants is increased. The advice therefore, also for those people is to leave.

Quite commonly in the Tasmanian environment, because of the steep terrain and the rapid firespread through spotting (fires started ahead of the fire by burning embers), there is little warning time. Escape routes become blocked by smoke, fire, falling trees or power lines. In such cases, when the dangers posed by escaping exceed those of remaining, clearly the best option is to stay.

Even organized evacuations are not always orderly. Inexperienced people faced with evacuation from a terrifying fire may behave irrationally. Being told to go by those in authority--police or fire officers--is the final signal that all is far from OK. Seeing and hearing people in authority anxiously urging people to leave sends a very strong message that disaster is imminent. The logistics of moving a lot of people quickly and safely make large scale evacuations very difficult. Television images of people with belongings packed, caught on blocked highways fleeing from danger, are not uncommon. The road systems in urban interface areas are not designed to handle high traffic flows and speeds, particularly when people are going in the opposite direction to speeding fire appliances. All of these are reasons against a fleeing strategy. Fleeing in the face of danger is a normal human instinct. Very obviously the option of not being there is the safest option, but as discussed, there are many reasons why this is always not a practical option.

In our position on evacuation, there is one as yet unmentioned scenario. There will be occasions, hopefully very rare, where a person by staying will most certainly be killed (in the opinion of the on-scene fire or police officer). In such cases, where a person's life is immediately at risk by them being in a particular location, they may be advised to evacuate. Should the advice be not heeded then evacuation can be ordered (with force if necessary). In Tasmania such action has the support of legislation.

Reference to the word evacuation is made in the position protocol only for the above scenario --when it is ordered. In other situations the word relocation is used. Relocation is used to differentiate between advice and compulsion. Relocation is voluntary, and may mean only local movement to a safe site which may be close by, such as across the street or with a neighbor. Evacuation is a very emotive word which may create mental imagery not conducive to orderly and calculated movement to a safe haven, and therefore it is only used in the context of compulsory movement.

Special reference is made in the position protocol to road closures. Roads often need to be closed during the passage of the fire and for some time afterwards. People who choose to leave need to be aware that they may be prevented from returning by closed roads. Those wishing to return to their property may similarly be prevented. There is a clear and reasonable duty of care by both the Fire Service and the Police to allow residents access to their property, but without increasing the chances of serious accident by allowing traffic to move along roads affected by smoke or burning debris.

Prepare, stay and survive put to the test

How did the prepare, stay and survive strategy work when put to the test? By January 1998, Tasmania, like much of Australia, was in the grip of an El Niño drought. In southern Tasmania, around Hobart particularly, the whole landscape was badly drought affected. TFS had issued a number of public warnings on the fire danger. On January 17, with extreme fire weather conditions forecast, a Total Fire Ban was declared, putting TFS on full alert. Then, at 3 p.m., the inevitable happened. With the temperature at 39°C and a relative humidity of 15%, a fire started in forest at Ridgeway in the foothills of Mount Wellington. About an hour later, with the wind increasing and control lost, the fire spread quickly towards Kingston to the south of Hobart. Downwind of the fire in the eucalypt forest were many five-acre bush dwellers. Considerable spotting activity caused rapid fire spread, and for most people there was little warning before the fire was upon them. Clearly our tactics were defensive, with the fire running free. Fire appliances were deployed from around the southern area in as many numbers as could safely be committed. (There were over a hundred incidents that day). It was anticipated that our firefighting resources would very likely be fully committed to house protection tasks. It was therefore vital that people living in the threatened areas were informed of the situation and advised of appropriate actions to take. In such circumstances, residents had a real role in protecting their properties and those of absent neighbors. TFS units endeavored to deploy to protect property as the moving fire front impacted. Once the direct effect of the front had passed, house protection tasks including basic firefighting were left for residents. This allowed firefighting crews to move on to more urgent priorities that included protecting the houses of those who had left, those who were unable to get home and, regrettably, of those who had not adequately prepared.

In accordance with the newly drafted Evacuation Position, people were advised via the media, particularly radio, to remain with their houses.The advice to stay also included information on what to do--such as blocking downpipes and filling gutters, shutting doors and windows, dressing appropriately and having basic firefighting resources ready.

In the early stages, the speed of the fire meant for many threatened residents, staying was their safest strategy, regardless of their level of preparation. The danger of last minute evacuation in those conditions, given the road system and the steep terrain, was considered the greater risk to people in the fire area, and therefore our advice was to stay.

Over a period of 24 hours the fire burned through about 3,500 hectares (8,750 acres) and directly threatened a conservatively estimated 1,000 houses. Many of the houses were situated on the edge of the bush interface in a very suburban setting, a lesser number were remotely situated deep in the bush. The level of preparation and fire protective measures varied from very good to dismal. Seven houses were lost and only one of those was occupied.

This very positive result was to a large part attributed by TFS, the media and the community, to the presence of residents who protected themselves and their property in close co-operation with the Fire Service.

Lessons learnt from this bushfire

Immediately after the fire was controlled, an investigation into the property losses was carried out using the same survey methodology that is used by the CSIRO, as well as by collecting information on preparation measures such as defendable space, access, and water availability. The buildings lost were mostly timber -clad with metal roofs. Most had deficient defendable space and access and about half had no available water for firefighting. About one week after the fire an independent researcher, Ms. Wendy Saunders, was engaged to ascertain from the residents directly affected by the fire, the extent of their preparedness to survive a bushfire and to gain an insight into how they behaved during the fire and the extent of their knowledge of what to do. The information was gathered using a questionnaire completed by 220 residents from within and adjacent to the fire area.

Generally it was found that the residents thought they were reasonably well informed on preventative and protective measures and what to do when there was a fire. The survey revealed that the great majority of people accepted our advice to stay. Of the small number that left, only a small percentage said that they would leave again if faced with a similar situation. The majority of all residents surveyed said that should a similar situation occur in the future, they would remain. Much valuable information was received which we will use to provide guidance for future delivery of information and education for interface and high bushfire risk communities.

One of the greatest concerns of residents interviewed was the lack of accurate information as the fire progressed, particularly relating to the fire's position and its likely direction. Information was regularly updated and passed to the news media. Many of the local radio and television stations provided 'live to air' coverage during the fire. Once daylight was lost, our reconnaissance helicopter was not able to fly, making accurate intelligence information more difficult to acquire during the night. Accurate and timely information on the situation is the lifeblood of all successful large scale firefighting operations. Residents also have a great need for information to enable them to make decisions. Providing such information is vital to the success of the prepare, stay and survive strategy and presents a considerable challenge for us in the future.

Future challenges

In the days that followed the fire there was considerable media interest both locally and nationally in relation to evacuation issues. Following substantial publicity of the success of the prepare, stay and survive strategy, the awareness and confidence of people in the community has greatly increased, as it also has for those responsible for managing bushfires. Getting the message across is likely to be much easier in future but there will be an ongoing challenge to ensure that the people in vulnerable communities are appropriately empowered to adequately protect themselves. This empowerment must extend beyond people knowing what to expect and how to react when threatened by bushfire. The strategy is only effective if it is preceded by adequate preparation which includes appropriate subdivision planning, house design and siting, through to house and grounds maintenance. The success of the prepare, stay and survive strategy relies heavily on the people in affected communities making appropriate decisions. Given that we have now adopted this strategy, we have a clear duty of care to ensure it is well understood by the community.

Evacuation as a safety strategy has in the past been supported and employed in the belief that people are prone to panic and irrational behavior when faced with an unfamiliar and threatening emergency situation. Evacuation from a bushfire can itself result in some people being exposed to greater safety risks at times, as well as often resulting in much greater property losses. In the absence of residents, property has to be defended by often limited firefighting resources. If people are well informed, prepared and empowered, they are capable of taking appropriate actions to protect themselves and their property without the need for evacuation or close supervision and direction by emergency services. Such active community involvement will free up firefighting re sources, allowing their more effective deployment.

During the height of the Hobart fire in January 1998 I observed the behavior of residents and I talked with a number after the fire. Certainly most were really frightened at the time but they appeared to behave rationally. I did not observe panic, nor did I hear of people behaving in a panicked way. I am quite sure that had an evacuation of affected residents been ordered, panic at least by some people would have been very probable. Not evacuating resulted in minimal disruption to individuals and the community generally. Individual and community anxiety and trauma were reduced. Most of all, injury and property damage was minimized. I, along with many others, am certain that large scale evacuations would have resulted in considerably greater property losses. In Tasmania, in the future it is extremely unlikely that any large scale evacuations of people threatened by bushfire will be necessary.

The father of bushfire research in Australia, the late Alan McArthur, over 30 years ago in his report on the Tasmanian fires of February 7, 1967 said: One feature of housing losses in these fringe developments was in fact that groups of houses tended to survive in some localities, notably along Waterworks Road. When these situations were investigated, it was found that in all cases a group of people under strong leadership had stayed and fought the fires with garden hoses, wet bags and any other rough and ready means available. This proved that houses could be saved and people survive in an environment of fire which few other people in the world have ever experienced.

Bushfires in Tasmania are inevitable. The combination of climate and weather with flammable vegetation and people will continue to produce fires. There has been, and there still is a commitment to controlling fuel levels through planned burning. As a strategy to minimize the intensity of bushfires, fuel reduction burning will continue to be very important but on its own, can not be a total solution. Whilst people,directly and indirectly, are by far the greatest cause of bushfires in Tasmania, controlling people and their use or abuse of fire is not a realistic or practical solution--accidents and stupidity are somewhat inevitable. Climate and weather to date are not capable of manipulation, and so bushfires will continue to occur. We must learn to live safely with them.

Empowering the communities at risk from fire to play an active part in their own protection is a viable long term strategy to enable safe co-existence with fire as an element of nature.

Further Reading:
Krusel, N. and Petris, S., 1992. Staying alive:lessons learnt from a study of civilian deaths in the 1983 Ash Wednesday bushfires. Fire Management Quarterly, 2:1-17.
Luke, R.H. and McArthur, A.G., 1978. Bushfires in Australia. Australian Government Publishing Service, Canberra. 359 pp.
Ramsay, G.C., McArthur, N.A., and Dowling, V.P.,1995. Planning in fire-prone areas: Building survival. Pp.142-150. IN: Brown, C. and Tohver, L.(Eds) BUSHFIRE! Looking to the future. Envirobook, Sydney. 175 pp.
Ramsay, G.C., McArthur, N. A., and Rudolf, L.,1995. Towards an integrated model for designing for building survival in bushfires. CALMScienceSupplement 4: 101-108.
Saunders, W.L., 1998. Community decision making in the face of bushfire. Proceedings of the Fifth Annual Conference of the Australasian Fire Authorities Council, Hobart, October 9-11, 1998.pp. 123-139.
Webster, J., 1989. The Complete Australian Bushfire Book. Thomas Nelson, Melbourne. 269 pp.
Wilson, A.A.G. and Ferguson, I.S., 1986.Predicting the probability of house survival during bushfires. Journal of Environmental Management, 23:259-270.

APPENDIX
TASMANIA FIRE SERVICE AND TASMANIA POLICE POSITION ON EVACUATION AND PROTECTION OF PEOPLE AND PROPERTY ENDANGERED BY BUSHFIRES.
Tasmania Fire Service having responsibility for the protection of life, property and the environment from fire, will make decisions in respect to dangers posed by bushfires. Tasmania Police has an obligation for the protection of life and property. Tasmania Fire Service and Tasmania Police will work together in the best Interests of the community.

1. Where adequate fire protection measures have been implemented, able bodied people are advised to remain in their homes during the passing of the fire front Exceptions are the aged, young children and incapacitated people. These people should leave, but only well in advance of the fire when safe to do so, as should all others who wish to leave the area. People remaining need to be appropriately dressed and equipped to extinguish any fires that start in and around their house Residents leaving should understand that they may not be able to return for some time because of closed roads Where adequate fire protection measures have not been undertaken, the occupants of houses should relocate to a safe area well in advance of the fire for their own safety.

2. Advice on the need for relocation should be given by the senior fire officer present. The police should be requested to effect and control relocation to a safe area. Relocation should occur in a planned and safe manner co-ordinated by police.
Able bodied people should be allowed to return to their homes as soon as possible after the main fire has passed. (Subject to 4).

3. Where in the opinion of the most senior fire officer present or a police officer that a person's life is immediately at risk by them being in a particular location they will be advised to evacuate either by a fire officer or police officer. The police officer will seek the advice of the senior fire officer prior to making a decision to evacuate, except in the most urgent of circumstances. In the event that such advice is ignored a police officer may order them to evacuate and has the legal power to enforce that evacuation.

4. Road Closures: Roads will be closed when they become unsafe (either through smoke, falling trees/power lines etc) and will remain closed until they return to a safe condition. Police will close roads as requested by the most senior fire officer present to facilitate the firefighting effort. Whilst roads are closed, access should only be allowed for emergency service vehicles. Residents/media seeking access may only be allowed access where an appropriate escort can be provided e.g. fire or police vehicle. This action will depend upon the priorities of the emergency services at the time.

-- J B Gledhill, Chief Officer, Tasmania Fire Service
-- R McCreadie, Commissioner, Tasmania Police