Eagle Creek Trail (Gorge) Closed by Fire (July 5)

[kepPNW]

http://koin.com/koin-video-extras/

as of 0847 it's at about -1:1500

Thank you! Found it. A few more snips...

[aircooled]

The women's dorm (lower left in first photo) appears to be in ashes.

[Rather B Hiking]

High Bridge is steel and though the tread may burn the structure should survive unless a tree falls on it. The new bridge at Tish is a thermoset composite with a wood tread and unless it gets extremely hot, should survive. - again, unless a tree falls on it!

I am going to disagree with that one. Wood ignites at 400 degrees F. If embers ignited the deck on either bridge, that bridge is probably gone.

Structural steel expands with heat, so at the very least the structure of High Bridge could warp. Depending on the specific alloy, steel fails (loses all its structural strength) at roughly 1100 degrees F. A forest fire can easily reach 1500 degrees F at ground level. Let's hope the fire skipped over that area with minimal damage.

Tish Creek bridge was closer to the initial intense fire, and is probably gone. Plastics may have higher or lower ignition temperatures than wood. Ignition temperature of high grade polyethylene, which is most commonly used in these composites, is around 350 degrees F. Ignition temperature of polypropylene is 570 degrees F.

The real problem with plastics is that they melt - at temperatures as low as 107 degrees F for low density polyethylene, 122 degrees F for high density polyethylene, and 158 degrees for polypropylene. So then you have molten plastic potentially falling into the fire plume. Once ignited, plastics produce twice as much heat per pound as ordinary combustible materials. Worst of all, plastics do not stop burning when the ignition source is removed. Have you ever melted the ends of cord or webbing, and then tried to stop the melting?

[aircooled]

It appears both dorms at Nesika burned down. You can see the remaining chimney of the women's dorm at lower left.

[Don Nelsen]

High Bridge is steel and though the tread may burn the structure should survive unless a tree falls on it. The new bridge at Tish is a thermoset composite with a wood tread and unless it gets extremely hot, should survive. - again, unless a tree falls on it!

I am going to disagree with that one. Wood ignites at 400 degrees F. If embers ignited the deck on either bridge, that bridge is probably gone.

Structural steel expands with heat, so at the very least the structure of High Bridge could warp. Depending on the specific alloy, steel fails (loses all its structural strength) at roughly 1100 degrees F. A forest fire can easily reach 1500 degrees F at ground level. Let's hope the fire skipped over that area with minimal damage.

Tish Creek bridge was closer to the initial intense fire, and is probably gone. Plastics may have higher or lower ignition temperatures than wood. Ignition temperature of high grade polyethylene, which is most commonly used in these composites, is around 350 degrees F. Ignition temperature of polypropylene is 570 degrees F.

The real problem with plastics is that they melt - at temperatures as low as 107 degrees F for low density polyethylene, 122 degrees F for high density polyethylene, and 158 degrees for polypropylene. So then you have molten plastic potentially falling into the fire plume. Once ignited, plastics produce twice as much heat per pound as ordinary combustible materials. Worst of all, plastics do not stop burning when the ignition source is removed. Have you ever melted the ends of cord or webbing, and then tried to stop the melting?

We will see - hopefully the fire skipped both areas. I was at the site of the Tish Creek bridge the day before it was placed and loggers were felling close-by trees in prep for the airlift in of the new bridge. Let's hope that was enough to keep the fire away or at least the worst of the heat. Miracles do happen - witness the survival of Nesika in spite of flames on all sides.

[drm]

We've heard that blowing embers are a big part of what spread this fire west so quickly, but those are likely to skip over one place and land somewhere else. Also I think ridges are more susceptilble for two reasons. They are more likely to catch flying embers, and deep canyons are much wetter and have a better chance of resisting ignition if an ember does land down there. I'm not saying no canyons burned, but I would expect that we will find that the ridges are much more toasted than the canyons.

It does appear that a decent portion of Benson Plateau burned, though not the center and central-east sections. Will a treeless Benson Plateau be less spooky?

[retired jerry]

"Will a treeless Benson Plateau be less spooky?"

That's what I was thinking

[pcg]

Will a treeless Benson Plateau be less spooky?

Same for Multnomah Basin. Any word on how that area has faired? I know the fire swept through Nesika Lodge, but I'm referring to the area west of there, directly above the Elevator Shaft.

[Chase]

If anything I would think standing dead trees would make it more spooky

[bobcat]

Interesting survivor story from Spokane. By his account, only one of the 150 + overnighters at Tunnel Falls had the essentials, and she was an immigrant who had been in the country only 6 years!

http://www.spokesman.com/stories/2017/s ... l-neve/#/0