Shawn ponders: >> I dunno?! I'll dig back into my old posts to see the forces involved >> were...I can't remember who figured it out before... >> >> >> Who was it that did the bungie/towrope calculations? >> >> Shawn Then, Shawn finds the old post he was referring to: A long, long time ago, Michael Daly wrote: > Let's assume a paddler weighing 175lb, in a kayak that is 55 lbs carrying > 70 lbs of gear for a total weight of 300 lb. We'll also assume a velocity > of 3 miles per hour. Plugging the results into our equation (with conversions > to get everything in inches, pounds and seconds) > > 3 mph = 3 (5280 * 12)/3600 = 52.8 inches per second. > > G = 32.2 ft/sec**2 = 32.2 * 12 = 386.4 in/sec**2 > > F = 52.8 sqrt[ (1.6 * 300)/ (386.4) ] = 58.8 lb. > > This sounds good; 58.8 lb is within the range that some folks considered > reasonable when it was discussed a while ago. And that's a worst case. > However, this requires the bungie to stretch under this load: Dave Seng wrote: >The thought that went through my mind was, "Gee, it would really S#_at_k to be >towing an injured friend through some tough water and have that lightweight >line break." Something else to remember is that as lines age they >deteriorate from sunlight, being walked on, salt crystals, etc. I'd want >the added security of a greater breaking strength and sacrifice the few >extra ounces and cubic inches.... While Mike's calculation of 60-ish pounds was a worst-case scenario, for a sudden stop, I should probably go for the 3/8" stuff. Especially considering what Dave pointed out: the deterioration factor! Shawn -- Shawn W. Baker 0 46°53'N © 2000 ____©/______ 114°06'W ~^~^~^~^~^~^~^~^~^\ ,/ /~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^ baker_at_montana.com 0 http://www.missoulaconcrete.com/shawn/ *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Tue Mar 28 2000 - 14:15:49 PST
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:30:22 PDT