During the Community Fire Protection Treatment and Demonstration Trials near Fort Providence, NWT, between June 14 and 27th, FERIC was able to collect temperature data from two Arctic Cat ATVs. These quads were used in the study plots to transport people and to pull trailers loaded with building supplies. The objective was to collect exhaust system surface temperatures from four locations on the exhaust systems as the ATVs were used under normal conditions. Once enough surface temperature data are collected, the length of time required to ignite fine fuels at these temperatures will be investigated.

Two ATVs - a 2003 Arctic Cat 500i Automatic and a 2003 Arctic Cat 400i (standard drive) -were equipped with thermocouples and dataloggers. Thermocouples were secured by clamps in the following locations:

• On the exhaust pipe at the manifold (Figure 1).
  
• Behind the heat shield halfway to the muffler.
  
• On the exhaust pipe right before the muffler (Figure 2).
  
• At the end of the muffler (Figure 3).

Figure 1. Clamp holding thermocouple to exhaust pipe at the manifold.

Figure 2. Thermocouple clamped directly before the muffler.

Figure 3. Thermocouple clamped to end of muffler.

Results

Data were collected for eleven days on the two ATVs and imported into spreadsheets. Graphs were produced for each day, illustrating the exhaust system surface temperatures for the four locations over the course of the day. Figure 4, taken from the 2003 Arctic Cat 400i (standard drive) for June 20, 2003 is an example of the results.

Figure 4. Exhaust system surface temperatures for June 20, 2003 from the 400i Arctic Cat.

Exhaust system surface temperatures, other than at the back of the muffler, remained above the ignition threshold for wildland fuels of 204 °C ¹ from 16:00 to 16:30. An interesting characteristic of these exhaust system surface temperatures is how quickly they increased and decreased (Figure 5). This physical characteristic means that riders can stop their quads for only a few minutes and surface temperatures will drop below the ignition threshold. At these times, a rider could clean off accumulated material as a preventative measure.

Figure 5. Data from June 21 showing how quickly exhaust system surface temperatures heat up and cool down around the ignition threshold.

Observations
Accumulation of Debris on Exhaust System

The two Arctic Cats were driven through various conditions and fuels, from dry and dusty conditions with cured grasses to wet and muddy conditions. Moss was also common in the area. The quads worked under normal conditions, occasionally hauling heavy loads through the bush as well as being used to transport individuals around the plots. During this riding, the small amount of debris accumulating on either quad was mostly mud that dried and fell off. These ATVs appear to have a design that limits the accumulation of fine fuels in the area suspected to be key in ignitions, that is, directly above the tire on the exhaust system where the muffler connects to the exhaust pipe. The tire and the exhaust pipe/muffler are separated, and only a few areas allow debris to be accumulated and held in direct contact with the exhaust system (see Figure 2).

Time required for ignition

Many conditions are required to ignite fuels on an ATV and then to start a wildfire (fuels, fuel moisture conditions, ATV temperatures, etc.). A combination of low relative humidity, cured grasses, and very dry fine fuels are needed. At this time, it is not known how long fuels have to be in contact with the exhaust system at temperatures high enough for ignition or smouldering. However, it is known that sections of the exhaust system experience surface temperatures greater than 204 °C for extended periods of time. Figure 4 shows that temperatures on the exhaust system immediately before the muffler remain above the ignition threshold for up to 30 minutes.
On June 7th at Hinton's FireSmart Community event, cured grass was placed on the exhaust system immediately in front of the muffler and the ATV was driven for about 90 seconds. After the short drive, the grass was visibly smoking and some smouldering was observed. The outside temperature was 24 °C and the relative humidity was roughly 30%. This showed both FERIC staff and the public the apparent ease with which ignition can take place.
Further research into the time required for ignition is required and will be undertaken by FERIC staff in the Fall of 2003.

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