Jump to content

Rope size for monkey bridge


Recommended Posts

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://scoutpioneering.com/2012/12/27/double-a-frame-monkey-bridge/said 1/2 or 3/4.

Edited by MattR
Link to post
Share on other sites

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?

Link to post
Share on other sites

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.  

Link to post
Share on other sites

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.

Link to post
Share on other sites

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....

Link to post
Share on other sites

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?

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...