Victoria’s advanced systems for engine crew protection

Above: Country Fire Authority test of engine burnover protection systems. Screen shot from CFA video.

The Aussies are far ahead of wildland firefighting agencies in the United States when it comes to the protection of personnel during fire engine burnovers and rollovers. Since 1977 Victoria’s Country Fire Authority (CFA) has been creating, evolving, and improving systems to increase the odds of firefighters on an engine surviving if their position is overrun by fire. These efforts were intensified after two engine burnovers in 1983 and 1998 killed a total of 17 firefighters.

During the last 39 years the vehicles have been hardened in various ways. Examples include internal radiant heat curtains and nozzles positioned around the exterior of the truck that spray water as the fire approaches.

We did a quick search on Wildfire Today for “engine burnover” and were surprised at the number of results. Take a moment and at least look at the titles and brief excerpts. These, of course, are just articles on our website. We make no claim that all engine burnovers are included since we started this website in 2008.

On November 21 the CFA posted a video (below) about their crew protection systems. It covers the history of their efforts and several minutes of video recorded during a test when a fire was ignited that burned over three of their engines to evaluate the effectiveness of the designs. The maximum temperature recorded was 728°C (1,342°F)

Below is a screen shot from the CFA video.

engine burnover protection system
Country Fire Authority test of engine burnover protection systems. Screen shot from the CFA video.

What if — in 2006 the five U.S. Forest Service firefighters that were entrapped and killed on the Esperanza Fire, instead of working on an engine similar to the USFS engine farther down this page, had been assigned to one built to CFA standards. Would they have taken refuge in the engine, pulled down the thermal protection shields and turned on the truck protection water spray instead of attempting to survive the fire outside the engine?

One feature of the CFA engines we noticed was a heavy-duty internal roll bar.

Internal roll bar Country Fire Authority engine
Internal roll bar in a Country Fire Authority engine.

We have written before about the need for U.S. wildland firefighting agencies to improve the survivability of engine crews during rollovers. These accidents involving large fire trucks, especially water tenders, are common.

In our opinion it is disgraceful that the outfits employing thousands of firefighters on engines have not taken this step to provide a safer working environment for their personnel.

The photo below is from one of the 34 articles on Wildfire Today tagged “rollover”.

Engine 492 crash Wyoming
On August 8, 2013 Engine 492 from the Medicine Bow-Routt National Forest and Thunder Basin National Grasslands was involved in a rollover accident on Wyoming State Highway 450 southwest of Newcastle, Wyoming. Three firefighters were injured, one seriously.

Thanks and a tip of the hat go out to Cameron.

Research: Wildfires in Sierra Nevada driven by past land use

Changes in human uses of the land have had a large impact on fire activity in California’s Sierra Nevada since 1600, according to research by a University of Arizona researcher and her colleagues.

Above: Indian Canyon Fire near Edgemont, SD, 2016. Photo by Bill Gabbert.

By Mari N. Jensen, University of Arizona College of Science

Forest fire activity in California’s Sierra Nevada since 1600 has been influenced more by how humans used the land than by climate, according to new research led by University of Arizona and Penn State scientists.

For the years 1600 to 2015, the team found four periods, each lasting at least 55 years, where the frequency and extent of forest fires clearly differed from the time period before or after.

However, the shifts from one fire regime to another did not correspond to changes in temperature or moisture or other climate patterns until temperatures started rising in the 1980s.

“We were expecting to find climatic drivers,” said lead co-author Valerie Trouet, a UA associate professor of dendrochronology. “We didn’t find them.”

Instead, the team found the fire regimes corresponded to different types of human occupation and use of the land: the pre-settlement period to the Spanish colonial period; the colonial period to the California Gold Rush; the Gold Rush to the Smokey Bear/fire suppression period; and the Smokey Bear/fire suppression era to present.

“The fire regime shifts we see are linked to the land-use changes that took place at the same time,” Trouet said.

“We knew about the Smokey Bear effect — there had been a dramatic shift in the fire regime all over the Western U.S. with fire suppression. We didn’t know about these other earlier regimes,” she said. “It turns out humans — through land-use change — have been influencing and modulating fire for much longer than we anticipated.”

Continue reading “Research: Wildfires in Sierra Nevada driven by past land use”

Understanding fire scars on trees

How does a tree damaged by a wildfire heal the wound?

Above: Annual rings of a Douglas-fir tree injured by two fires. The rings growing before the injury in 2003 were filled with resin to create a boundary from infection at the injury site. Wood grew over the dead cambium, enclosing the injury. Then the tree was injured in 2007 and woundwood again enclosed the injury. Note that the bark apparently remained intact both times. Photo: U.S. Forest Service.

From the U.S. Forest Service

When trees are injured they develop physical and chemical boundaries around the injury wound to resist infection. Trees also grow new wood to close over the injured place. Injuries caused by fires result in fire scars and we use the patterns of scarring among many trees to understand when and how often fires burn.  This research helps to understand the biological process of fire scar formation and use it to improve fire history analysis.

Fire history information is used to interpret the ecological role of fire and other disturbance events in ecosystems and is required in environmental assessments. Fire scars in different tree species don’t all look the same, which can lead to confusion about whether irregular growth in wood is a scar. This research examined the process fire scar formation and the anatomy of fire scars in conifer and hardwood trees.

In three species of trees that survived wildfires near Missoula, Montana (western larch, Douglas-fir, and ponderosa pine) we found that injuries happened even when bark was not charred. This was also true of oak trees we examined that burned in a prescribed fire in Ohio hardwood forests. It would be impossible to know that the tree had a scar by just looking at it. Where a tree’s bark was rough, both hardwoods and conifers sometimes had several small injuries next to crevices in bark where heat could get to living cells more easily. Hardwood trees produce chemicals to resist infection, mostly phenols. Conifer trees produce resin (terpenes) as a physical and chemical barrier to block infection.

larch fire scar
Disk taken from a western larch injured in a wildfire in 2003, showing the development of a fire scar in following years around the edges of the killed cambium as wood grows over and around the dead cambium. Photo: Ken Dudzik.

Key Findings

  • The stems of western larch, Douglas-fir, and ponderosa pine trees can be injured from fire even when the bark isn’t visibly charred. Heat alone causes the injuries, especially where bark is thinner.
  • Western larch, ponderosa pine, and Douglas-fir ordinarily make resin in cells called resin ducts. After an injury western larch and ponderosa pine produce many extra (traumatic) resin duct cells, and in turn these ducts produce and transport a lot of resin. Traumatic resin seems to be a better disinfectant than the usual resin. In larch traumatic resin ducts are especially large and effective at transportation. Douglas-fir trees don’t produce traumatic resin ducts, so after an injury they produce relatively less resin, and less effectively transport it. They tend to die more easily than larch or ponderosa after a fire.
  • In years following a fire, wood grows around the edges of the injury. The density of wood cells is higher at the edge of the injury and when they grow, the tree ring at that point is unusually wide. If the injury is small, within a few years it can close over and be invisible from the outside. Sometimes injuries are never visible from the outside.
  • Knowledge about why these differences occur in a particular species can help us understand how scars are formed, why some trees survive or die after injury, and determine whether irregularities in wood anatomy are likely to be a fire scar.
tree fire scar
Kevin Smith (Northern Research Station) and Elaine Kennedy Sutherland (Rocky Mountain Research Station) examine a fire-caused injury up the length of a tree from the Lolo National Forest, Montana.

Live event to discuss wildfire wind tunnel studies

Above: The U.S. Forest Service tests burning pine straw in an IBHS wind tunnel earlier this year. Screen grab from IBHS video.

The Insurance Institute for Business and Home Safety (IBHS) will host a live wildfire-related event on Facebook Wednesday November 9 at 10:30 a.m. EST. They have not provided a ton of information about but it will “open up the curtain a bit on wildfire studies”. (Link to the IBHS Facebook Page.)

Dr. Steve Quaries will discuss the wildfire research that they have been doing in the huge wind tunnel. In 2011 using 105 huge fans and spark-generators, they launched embers at a structure to demonstrate what can happen when a wind-driven fire approaches a poorly prepared structure.

IBHS wind tunnel
The IBHS wind tunnel showing the 105 fans. IBHS photo.

The video below shows embers igniting flammable material on and around a structure in the IBHS wind tunnel.

Earlier this year the U.S. Forest Service used the facility to study the relationship between wildland fire rate of spread and wind speed used in the U.S. wildland fire behavior decision support systems. Previous experiments have been conducted in the Missoula Fire Sciences Laboratory wind tunnel that is more limited in size and wind speed than the IBHS wind tunnel.

This research is a collaborative effort with researchers at UNC Charlotte, University of Maryland, University of Texas Austin, and USDA Forest Service, and is funded by the Joint Fire Science Program.

Using soil moisture in grassland fire danger rating systems

“…Our research findings provide scientific justification for using soil moisture data from in situ monitoring networks in fire danger rating systems. Such soil moisture data are increasingly available and are not currently being used in the context of wildfire preparedness. ”

Above: The percent of maximum soil moisture available to plants in the top 16 inches in Oklahoma, September 11, 2016.

David M. Engle, along with other scientists at Oklahoma State University, are making a case that soil moisture should be used as one of the components in determining grassland fire danger ratings.

soil moisture station
Station that measures soil water at several depths and transmits the data. This image and the one above are courtesy of the researchers.

To assess the herbaceous fuel dynamics in grasslands, they conducted 3 studies:

1) A study that used a database of large wildfires in Oklahoma to examine the relationship of fire occurrence and fire size with soil moisture;

2) An intensive field-based study to quantify and subsequently model herbaceous fuel load and moisture content in grassland patches that differed in time since fire and, therefore, proportion of live and dead herbaceous fuel load, and;

3) Modeling the influence of herbaceous fuel dynamics and weather conditions on fire behavior in tallgrass prairie.

Their final report can be read HERE.