# Accumulated Pressure of wound string **URL:** \ **Category:** In My Humble Opinion\ **Created:** [August 5, 2016, 9:11pm UTC](https://boards.straightdope.com/t/accumulated-pressure-of-wound-string/761877 "2016-08-05T21:11:33Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [August 5, 2016, 9:11pm UTC](https://boards.straightdope.com/t/accumulated-pressure-of-wound-string/761877/1 "2016-08-05T21:11:33Z")
If I took a string say with a 1% elasticity under 10# tension and another string with 0 stretch under 10# for examples. Let’s say the string had a breaking strength of 50# and was being wound up on a fishing reel level across the spool with no windings beneath it. The spool would not compress under this load. We simply used a fishing pole to reel up a 10# weight. Would the compression on the spool be the same?? It seems like the no stretch string would give up its tension if left static but maybe not ---
**Author:** ![octopus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/octopus/32/3716_2.png) [@octopus](https://boards.straightdope.com/u/octopus)\ **Post date:** [August 5, 2016, 9:31pm UTC](https://boards.straightdope.com/t/accumulated-pressure-of-wound-string/761877/2 "2016-08-05T21:31:15Z")
Here’s a link that may help. > **[Mechanical Engineering](https://books.google.com/books?id=pmIfAQAAMAAJ&pg=PA675&lpg=PA675&dq=total%2Bpressure%2Bof%2Bwound%2Brope&source=bl&ots=YvCn-QpeyD&sig=aFGUtDGFR3kEptXxtzvRqZRsIPM&hl=en&sa=X&ved=0ahUKEwidy4CJnKvOAhVH2B4KHUZ8A3UQ6AEIHDAA#v=onepage&q=total%20pressure%20of%20wound%20rope&f=false)** > > "History of the American society of mechanical engineers. Preliminary report of the committee on Society history," issued from time to time, beginning with v. 30, Feb. 1908. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [August 5, 2016, 10:14pm UTC](https://boards.straightdope.com/t/accumulated-pressure-of-wound-string/761877/3 "2016-08-05T22:14:58Z")
> [@octopus](#): > > Here’s a link that may help. > > [Mechanical Engineering: The Journal of the American Society of Mechanical ... - American Society of Mechanical Engineers - Google Books](https://books.google.com/books?id=pmIfAQAAMAAJ&pg=PA675&lpg=PA675&dq=total+pressure+of+wound+rope&source=bl&ots=YvCn-QpeyD&sig=aFGUtDGFR3kEptXxtzvRqZRsIPM&hl=en&sa=X&ved=0ahUKEwidy4CJnKvOAhVH2B4KHUZ8A3UQ6AEIHDAA#v=onepage&q=total%20pressure%20of%20wound%20rope&f=false) It gave a beautiful explanation but I didn’t see where it addressed elasticity in the rope. Possibly because all ropes have at least some elasticity ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [August 6, 2016, 6:42pm UTC](https://boards.straightdope.com/t/accumulated-pressure-of-wound-string/761877/4 "2016-08-06T18:42:47Z")
I’ve read the OP several times and am still not sure I understand it. Are you assuming the fishing line is perfectly inelastic, and comparing it to the “string” which _is_ elastic? ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [August 6, 2016, 8:27pm UTC](https://boards.straightdope.com/t/accumulated-pressure-of-wound-string/761877/5 "2016-08-06T20:27:13Z")
Yeah, there’s no such thing as zero elasticity. And elasticity matters little to the pressure on the spool, except where it changes the surfaces involved. In both cases what the spool has to deal with is the 10 pound tension. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [August 6, 2016, 10:36pm UTC](https://boards.straightdope.com/t/accumulated-pressure-of-wound-string/761877/6 "2016-08-06T22:36:24Z")
> [@scr4](#): > > I’ve read the OP several times and am still not sure I understand it. Are you assuming the fishing line is perfectly inelastic, and comparing it to the “string” which _is_ elastic? No I wasn’t assuming that, I was wondering what the effect would be if a string did have zero elasticity. They have some strings out now with very low stretch. I have had fishing reels implode when I was younger from winding them too tight. Now I use the poll to avoid this. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [August 7, 2016, 12:41am UTC](https://boards.straightdope.com/t/accumulated-pressure-of-wound-string/761877/7 "2016-08-07T00:41:19Z")
Discussion here [Need some advice on winch drum calculations](http://www.eng-tips.com/viewthread.cfm?qid=316932) and here [Winch drum wrapping pressure](http://www.eng-tips.com/viewthread.cfm?qid=379545) and here [winch drum thickness](http://www.eng-tips.com/viewthread.cfm?qid=332009) ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [August 7, 2016, 3:26am UTC](https://boards.straightdope.com/t/accumulated-pressure-of-wound-string/761877/8 "2016-08-07T03:26:27Z")
> [@astro](#): > > Discussion here > > [Need some advice on winch drum calculations](http://www.eng-tips.com/viewthread.cfm?qid=316932) > and here > > [Winch drum wrapping pressure](http://www.eng-tips.com/viewthread.cfm?qid=379545) > > and here > > [winch drum thickness](http://www.eng-tips.com/viewthread.cfm?qid=332009) It is an interesting problem. I really had no practical reason for asking this beyond what I have experienced with windings on drums in the past. The no stretch scenario I found interesting because it would seem that even if you locked it down in plce once wound it would still lack tension unless it hd a steady pull. Maybe not. Zero stretch is pretty hard to comprehend in this type of problem.