Blasting at Triple Falls

This is a forum for trip reports that pre-date the Portland Hikers forum, trail photos from pre-digital era, or any other discussions that focus on trail history.
Post Reply
pcg
Posts: 269
Joined: May 31st, 2011, 7:46 pm
Location: Chehalem Mountain

Blasting at Triple Falls

Post by pcg » October 22nd, 2016, 1:44 pm

Several years ago I found a mass of wadded up wire on the banks of Oneonta Creek, about thirty feet below Triple Falls. It is thin (18 ga. ?) yellow twin cable and I'm guessing it was used to detonate blasting caps. It was at the base of the cliff that is below the viewpoint immediately below the falls so maybe it was used to blast that area out and workers just tossed it over the edge? Anyone know what blasting was done and when?

C.C. Hon
Posts: 21
Joined: May 28th, 2008, 10:03 pm

Re: Blasting at Triple Falls

Post by C.C. Hon » February 20th, 2017, 1:52 pm

The blasting was done in 1984 or 85. At that time, there was no bridge across Oneonta Creek. About 50-75' of new trail bench was shot into solid basalt on the slope just north and west of the present Triple Falls crossing, creating a new approach trail to the present bridge site.

A native log bridge with handrails was built at the present crossing. The design work, layout and control for the trail construction, the bridge and the excavation by blasting was done by Forest Service engineers. The construction was done by a private contractor.

The rock was drilled with a gasoline powered hammer drill (Pionjar). A water gel explosive product (Tovex, I think) detonated by electric blasting caps, was used in the blasting.

pcg
Posts: 269
Joined: May 31st, 2011, 7:46 pm
Location: Chehalem Mountain

Re: Blasting at Triple Falls

Post by pcg » February 21st, 2017, 4:59 pm

Thank you!
I knew someone somewhere must know the answer to this.

Post Reply