In mid-March 2018, a bush fire tore through Cobrico in Victoria’s south-west,igniting the peat bog underneath. This left behind toxic levels of carbon monoxide and caused the temporary relocation of 20 per cent of residents. After attempting to bring the fire under control using helicopter water bombing, it was decided that a four kilometer layflat hose system would be a more efficient solution to extinguish the threat.
The fire that tore through Cobrico, burned over 15,000 hectares of land in a peat bog. During the first couple of weeks, firefighters worked day and night using fire trucks, helicopters and bulldozers to try to contain it. However, peat or coal fires are extremely difficult to manage as they require a significant amount of water running continuously to extinguish them.
Peat is created over time in wetlands through the build-up of partially decayed vegetation such as leaves, grass and root systems. Once ignited, it a challenge to extinguish and can burn for months or years. It burns similarly to coal briquettes, emitting significant smoke as it does. This smoke contains fine particles, water vapour and gases including carbon monoxide and nitrogen oxides which are odorous.
If left to burn, the Cobrico peat fire could have spread through the vegetable matter up to 10m below the surface and damaged prime farming land.
Bringing water to the peat fire
Since the traditional method of using fire trucks and the expenses of helicopter water bombing were not having the desired effect, the decision was made by the local authorities to flood the area using large volumes of water. After careful consideration of the pipeline options available to bring in this water, flexible layflat hose was decided upon as the most efficient and economical option. 200mm diameter layflat was rapidly connected to a valve in the Major Ottway Pipeline, four kilometers away, and this brought water to the peat fire in just 48 hours.
State Emergency Management Commissioner, Craig Lapsley, said that with no decent rainfall on the horizon, an above-ground temporary pipeline was deemed the only feasible way to get a constant and significant amount of water onto the peat fires in a short time. “One of those is to put above-ground piping to bring [water] from a major reticulation main — it’s quite extensive but necessary without rain,” Mr Lapsley said.
Installing the solution
The temporary pipeline was assembled using Crusader Hoses’ flexible layflat hose(fully Australian made) which was supplied on reels of 200m plus some shorts. Agmek Pty Ltd from Ballarat was the contractor, due to having the layflat in stock plus their experience in mine dewatering. Agmek easily and efficiently transported the hose to site in only three truckloads, due to it’s compactness. The full four kilometers of hose was unrolled and in-situ within one and a half days. The water was soon flowing through at 50 litres per second at 10 bar pressure and this rapidly contained the fire behind an inactive edge.
The segmented hose pumps water 24 hours a day alongside roadsides and across paddocks until it reaches two dams dug at the edge of the peat fire at Lake Cobrico. There are irrigation pumps going from the dams into sprinklers which directly attacks the fire. The water is also being used to flood a trench which is acting as a fire break.
The construction of the pipeline took just 48 hours — one expert said such a feat would ordinarily take weeks — and is understood to be the first time such a method has been used to fight a peat fire in Victoria.
Mike Jones, Managing Director of Agmek, said, “We have been in the deployment of water pipelines for over 30 years and we are happy that the benefits of flexible layflat hose systems were proven in extinguishing the Cobrico peat fire.”
Once the layflat hose and pump was installed, roads were reopened without obstacles as the hose had been placed in culverts at crossings and ran alongside. The layflat hose was deployed with minimal environmental impact and a soft footprint. The layflat hose will next be retrieved by rolling it up on reels or pallets. It will then be ready to move water again at whatever site it is needed at.
Francois Steverlynck, the MD of Crusader Hose also suggested that their large diameter layflat hose could have also been used at the Hazlewood coal mine fire in February 2014. “Imagine the volumes they could have pumped by using our 200mm diameter layflat hose?”
For more information, go to www.crusaderhose.com.au