Jump to content



Photo
- - - - -

Rope size for monkey bridge


  • Please log in to reply
6 replies to this topic

#1 MattR

MattR

    Member

  • Members
  • 825 posts

Posted 23 February 2017 - 12:44 PM

Any opinions on rope size for the main rope of a monkey bridge. We have 1/2". Was wondering if 3/4 or 1" would be better. It's probably harder to tie but I was going to put an eye splice in the end and use a come-a-long to tighten it. We're thinking 20-30' for the span between the frames.

 

A website I found https://scoutpioneer...-monkey-bridge/said 1/2 or 3/4.


Edited by MattR, 23 February 2017 - 12:45 PM.

  • 0

#2 qwazse

qwazse

    Senior Member

  • Members
  • 6006 posts

Posted 23 February 2017 - 01:06 PM

3/4 will work, but as an uncoordinated kid, I always felt more stable on a 1" rope. A splice sounds like a great way to increase stability.

 

1/2" Might not withstand the tension in a 30' span.

 

Has anybody modified the monkey bridge design with Kevlar, a.k.a. slack line?


  • 0

#3 SSScout

SSScout

    Senior Member

  • Members
  • 3903 posts

Posted 23 February 2017 - 01:13 PM

I like the website you reference.  That said, I have never seen a working Monkey bridge (county fair with public guided over it? Camporee? ) with a less than 7/8 or 1 inch manila hawser on the foot rope.  This is expensive stuff and needs to be taken care of each up and down, but it would, I think, give more confidence in the construction.  1/2 inch for the hand ropes and ties.  I especially like the double a-frame supports.  And the ring tackles for tightening.  


  • 0

#4 TAHAWK

TAHAWK

    Senior Member

  • Members
  • 2542 posts

Posted 23 February 2017 - 01:19 PM

Not that this is news, but new rope is stronger than used rope.  The local FD gives us rope annually that's fine for non-life-at-stake applications, but too old/used for their standards.


  • 0

#5 MattR

MattR

    Member

  • Members
  • 825 posts

Posted 23 February 2017 - 01:47 PM

3/4 will work, but as an uncoordinated kid, I always felt more stable on a 1" rope. A splice sounds like a great way to increase stability.
 
1/2" Might not withstand the tension in a 30' span.
 
Has anybody modified the monkey bridge design with Kevlar, a.k.a. slack line?


That's a great idea. Cheaper. Includes a tightener. Much easier to sell to the scouts. Easier to walk on. We can use it as a regular slackline at another event.
  • 0

#6 SSScout

SSScout

    Senior Member

  • Members
  • 3903 posts

Posted 24 February 2017 - 09:16 AM

The difference in rope is very telling. Manila will stretch some , but not as much as nylon/poly.   I tried to move a big rock with a block and tackle using Plymouth Goldline, and I just watched in amazement as the rope stretched and stretched and stretched but the rock did not move!  I doubled the length of the rope, and it did not fail!   Finally the rock moved, but wow....


  • 0

#7 Stosh

Stosh

    BSA Heretic

  • Members
  • 11368 posts

Posted 24 February 2017 - 08:16 PM

There's a story behind the expression used when someone was complaining about something, "You'd complain if you were hung with a new rope."

 

The executioner would "condition" the rope before the execution by hanging heavy bags of sand for a long period of time.  The rope was manila.  A new rope would have too much elasticity in it and the person would bounce around on the end of the rope as if they were "dancing".  Not a pretty sight.  So all the elasticity of a new rope was taken out of it before use.

 

Isn't that a bit of pleasant cocktail conversation you'd want to slip in sometime in the evening?


  • 0

Stosh

 

There's a reason why I don't always answer the phone, doorbell or comments on forums.  :)





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users


IPB Skin By Virteq