Foss Trip Report
Printed From: ProfessorPaddle.com
Category: General
Forum Name: Whitewater Forum
Forum Discription: Open Discussion Forum. Whitewater related subjects only
URL: http://www.professorpaddle.com/forum/forum_posts.asp?TID=7539
Printed Date: 05 Oct 2025 at 11:10am
Topic: Foss Trip Report
Posted By: Otter Boy
Subject: Foss Trip Report
Date Posted: 16 Nov 2008 at 9:40am
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We had a good day on the Foss. By “good day” I mean all the gear and paddlers were recovered. There was some excitement at Ken & Barbie, and we got to chase a swimmer for a while.
The boat and paddle fetched up on the same log jam a several hundred yards downstream. By some miracle they were in the exact same spot in the logjam, and this after quite a bit of unattended class IV creeking. I’ve never seen anything like that before. Leif, Jeff and I had to bust out ye olde z-drag to get the boat off, but it wasn’t a huge job. I’ve been boating over 10 years, and the only times I’ve had to make a z-drag for real have been on the Foss. Not sure what to make of that…. We all need to practice rope rescue work! We had an experienced crew, and we still had difficulties getting things set up under real-world conditions. Fine for a boat recovery, but no good at all in a true rescue situation. Foss Wood Report: Clear as of 11/15/08. Some logs to work around, but nothing serious given the standards of creeking in the Pacific Northwest. Expect this to change with the next rain event. A day on the Foss without a wood portage is a rare day indeed. Technical note: We had problems with the prussic slipping on the rope. I think this was because the prussic line was to large diameter compared to the rope itself. Both the prussic chord and throw rope were “standard” gauge. Does anyone have a suggestion of the best way to fix this? I’m hesitant to user smaller gauge prussic chord given the forces involved. Should I just buy a thicker rope? - Otterboy |
Replies:
Posted By: Kiwi
Date Posted: 16 Nov 2008 at 9:51am
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5 mm dyneema cord.
you can get it at climbing stores or online it think.
it's good to something like 25 KN.
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Posted By: Hunter
Date Posted: 16 Nov 2008 at 10:02am
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Otterboy
Did the wood you had to "work around" still leave enough room for catarafts? I have been want to row this section for quite some time...... Hunter |
Posted By: Otter Boy
Date Posted: 16 Nov 2008 at 10:08am
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I'm not the right guy to talk to about catboats. As of yesterday there were not significant blocking issues, but I think you would want more water than we had. Of course more water = moving wood.
Are there any cat boaters who would weight in on this? |
Posted By: huckin harms
Date Posted: 16 Nov 2008 at 10:38am
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NOT a Catboater, but here's my two cents (based on yesterday's flows)
First, you would need a bunch more water, esp when running thru the 'picket fence', just below Ken&Barbie, a prescout of this would be wise. Can't really see wood being much of an issue, as the river is pretty free of it, as OB mention by NW standards. The big rootball that used to be in the left side of the picket fence is gone. Fun run for sure! Glad to hear the gear was recovered....
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Posted By: water wacko
Date Posted: 17 Nov 2008 at 5:48am
Otter, get prussik cord that is a third to half the size of the main line. Prussik cord is strong and shouldnt be a problem if youre using a proper barrel knot. Check out the rescue vid called Staying Alive. It came out several years ago and goes through ALL of the knots and hitches as well as systems. If it slips its too big, if it binds up, leaving marks on the rope its too small. Good luck. Play with that gear!  ------------- "Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." ~Howard Thurman |
Posted By: Liz
Date Posted: 17 Nov 2008 at 8:03am
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I'm at work and since gear is my gig, I'll throw my 2 cents in.
I think you have the NRS Pro Kayak Rescue Bag (NRS item #1824 Aside: Which, by the way, is the only throw bag kayakers or rafters should have (there is a larger rope for rafters). A regular kayak throw rope made out of polypropylene will hold only about a third of the weight of this "pro" rescue bag. If you're going to carry a rope, carry one that has enough strength to be used in a rescue situation if/when need be.) The NRS Pro Kayak Rescue Bag is made of 1/4" (6.35mm) Dyneema rope. Without knots, it's max load is 2600 lbs. With that thickness of rope, NRS recommends a 5mm prusik cord. This is the combo they put in their Kayak Un-Pin Kit (Item #1817).
Standard prusik cord is 6mm and is typically used with 1/2" rope. 5mm prusik cord has about 1,134 to 1,540 pounds of (about 5.5 kN) tensile strength. It's not typically used in rescue systems, but it is still available. 4mm cord has a 1,034 lb. tensile strength, 3mm has a 594 lb. tensile strength, and 2.75 and 2mm cord is not rated for a stress load.
1" tubular webbing has 4000 lb. tensile strength, and your carbiners and pulleys will all hold more than 6000 lbs. So, since your system is only as strong as the weakest link, your system can hold a little over 1,000 lbs. when you use the 5mm prusik.
If you get a bigger rope, such as a 3/8" standard raft rescue throw bag, you can use a larger prusik (6mm for sure, maybe even 7mm) and get an additional 800-1700 lbs of strength added to your system. The larger system may be hard to fit in your boat? ------------- |
Posted By: franzhorner
Date Posted: 17 Nov 2008 at 2:28pm
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There are also other ways of making a movable attachment points on a rope that don't require prussik cord..... We should all study our gear, technique, systems, and knots more than we do ------------- MORE RAIN PLEASE |
Posted By: Otter Boy
Date Posted: 17 Nov 2008 at 11:10pm
| Can you enlighten us? :) |
Posted By: slickhorn
Date Posted: 18 Nov 2008 at 11:35am
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Originally posted by -Liz your system is only as strong as the weakest link, your system can hold a little over 1,000 lbs. when you use the 5mm prusik. Great point Liz. To overcome these problems, I don't carry prussiks. Well, I carry them, but I don't use them as my primary friction knot. Instead of 5mm prussik cord (which is the weak link, as Liz points out) I use one of these: http://www.rei.com/product/722354 - http://www.rei.com/product/722354 witha rating of 22kN and attach it to my rope system using a kleisheist knot: http://www.thepirateking.com/knots/knot_kleimheist.htm - http://www.thepirateking.com/knots/knot_kleimheist.htm I haven't had a problem with this system slipping at load. I would issue one warning: with a strength of 22kn on that sling, you should have most of your system built with things that are rated at ~20kN. This greatly increases the chance that the whole system fails catastrophically, and at higher loads. So, you want to put a change of direction coming off the anchor so you can get the team working the ropes out of the line of fire if equipment fails. If you prefer prussiks, an easy solution is to carry 4mm and 5 mm prussik loops for 1/4 or 3/8 rescue line. --b ------------- |
Posted By: franzhorner
Date Posted: 18 Nov 2008 at 3:55pm
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Slickhorn just gave one way but there are many others. Refer to Les Bechdel and Slim Rays river rescue manual.... I myself have only used the prussik way. I've also seen direction figure 8s used but these are not movable.... ------------- MORE RAIN PLEASE |
Posted By: franzhorner
Date Posted: 18 Nov 2008 at 5:51pm
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Bachman and Kleimheist hitches are some alternatives. You can make these with prussik cord or webbing..... ------------- MORE RAIN PLEASE |