News & Media

Kaladbro Swamp peat fire - case study

By: Duncan Russell

Category: Operational Information

  10.24 AM 1 March, 2016


Location: General

Views: 1786

The ‘Learning from incidents’ section of Brigade magazine includes case studies of major incidents researched by Fire & Emergency Management. Here, the team analyses the 2015 Kaladbro Swamp peat fire.

A case study is an explanatory story based on a real-life incident that looks at what happened and why it happened. The aim is for people to learn from the case study so they improve their decision making in time-critical situations.

If you have any observations or initiatives you would like to submit from your own experiences in emergency management, visit the Observation Sharing Centre: http://www.surveygizmo.com/s3/1449131/observation-sharing-centre

Summary

On 7 November 2015, a peat fire was reported at Kaladbro Swamp around 30 kilometres north-west of Dartmoor in south-west Victoria. The fire appeared to be the result of a lightning strike to a fence which ignited the peat in 12 hectares of a 400-hectare peat swamp, to a depth of up to three metres.

Firefighters from CFA, the South Australian Country Fire Service, DELWP and Parks Victoria went to extraordinary lengths to contain the peat fire, with support from other agencies including Department of Health and Human Services, Glenelg Shire, Ambulance Victoria, Victoria Police, the Environment Protection Authority and the property owner.

What is a peat fire?

Peat is partially decomposed plant matter formed in wetlands and harvested as fuel. Unlike regular fires, the problem with peat fires is they can burn for long periods of time – months, years and even centuries. Also, it can take up to seven or more litres of water to wet a portion of peat the size of a one-litre milk carton. These fires can go into the soil and travel underground, which makes the firefighters’ task much more difficult because they can spread very slowly and surface anywhere.

Incident overview

During early morning on 31 October 2015, there was significant lightning across Glenelg Shire, and CFA and DELWP responded to many fires caused by lightning. These were all brought under control by 2 November. Aerial detection flights were used to detect any further fires which hadn’t been reported.

On 7 November, a fire was reported at Kaladbro Swamp. A lightning strike on a fence ignited the peat in a 400-hectare drained peat swamp. Containment works immediately began including the construction of a containment trench around the perimeter of the fire to restrict further spread.

The initial response to this fire was within normal CFA response arrangements: a Level 1 incident reporting to the district rostered duty officer in District 4. The fire was managed for the first 10 days within the group structure, with control strategies developed to initially contain the fire.

Crews responded using tankers to contain the fire edge and to construct a channel using excavators to provide a physical barrier. This was to prevent the fire spreading into large areas of forest plantations (including both pines and blue gums) within 500 metres, and rural agricultural areas with scattered buildings. The relatively low depth of peat meant this was successful, because there was a good clay base just below

the peat. Later in the firefight, these excavators were used effectively to dig out the peat, turn and break it up so water and foams were more effective. This work significantly reduced the suppression time.

CFA continued to regularly monitor the area through the summer.

Lessons identified

The use of a foam class in a lower concentrate Foams with the lowest proportioning rates between 0.1 and 0.5 per cent generally have relatively fast drain times, which release solution for rapid wetting. The lower concentrate was used on this fire, which penetrated the peat at a faster rate.

Straight tips provided better penetration than fog branches

Using the straight tips:

• gave a long reach to penetrate flames

• was least affected by wind

• was less affected by radiant heat

• attacked the seat of a fire.

In comparison, fog branches (not used on this peat fire):

• produce extremely fine particles of water that form a mist or fog stream but has the shortest reach

• are affected by wind

• can impede visibility

• use more water than the jet/straight tip.

The use of thermal imaging cameras Thermal imaging cameras were used at the peat fire. They allowed the crew to see through smoke to assess the extent of the fire, improved safety and, most importantly, they identified hot spots burning underground which could surface anywhere.

Compressed air foam system equipment CAFS was used to help crews apply firefighting foam to the fire. It worked well by penetrating the ash layer, preventing oxygen from combining with fuel and disrupting the chemical reaction required for the fire to continue. The sustained blanket of foam allowed steam underneath to remove heat from the peat.

Strategy to construct a trench/moat The trench was constructed to form a physical barrier to contain the peat fire. Firefighters excavated to the depth of clay so that the fire couldn’t burn and spread underneath the trench. They then flooded the area with water and this strategy was a huge success.

The use of P2 particulate filter masks P2 filter masks were necessary for all crew members because of the huge amount of dust and ash around the peat. Unfortunately, as their breathing became restricted, the crew needed to change masks frequently because the disposable masks have a short life span.

The use of Bollé goggles With dust and ash surrounding the peat, Bolle Nitro goggles protected the crews’ eyes well. They provided better protection than the standard goggles because they didn’t allow the fine dust particles to enter the goggles via the vents.

Water supplies Containment and control of the fire needed huge and reliable quantities of water over an extended period of time. As there was no surface water available at the site, two large irrigation bores were constructed next to the fire and fitted with high capacity submersible pumps and delivery pipes by the property owner shortly after suppression commenced.

Carbon monoxide These fires can release significant quantities of carbon monoxide gas (measured at up to 300 parts per million). Appropriate measures should be implemented early to monitor gas exposure for crews, contractors and nearby communities, and to introduce appropriate work practices and equipment to ensure their safety.

Conclusion

Peat fires are not common in Victoria so CFA members have little experience dealing with them. However, the first crews on scene implemented direct attack on the entire perimeter to contain it. The fire was brought under control in 10 days thanks to the great efforts of the crews coupled with the cooperation of the property owner.

Last Updated: 08 April 2016