UKC

I'm looking to set up a slackline in the garden and will be using two ground anchors in the absence of any suitable trees! For each anchor I'm going to wrap galvanised chain around a length of steel pipe and bury this in concrete (there are quite a few details of this around on the internet).

http://slackline.hivefly.com/slackline-without-trees/

My question is in connecting the chain to the slackline. I am planning on using a bow shackle with a jaw opening of 31mm to suit the slackline loop which gives a W.L.L. of 4.75 tons. Is this rating sufficient or does the shackle need to be be able to take more? Does anyone have any advice on this and is a bow shackle the best option?

Thanks!

If you're pulling more than 20 ton (W.L.L. x SF of 5:1, not unreasonable) I'd be more worried about either your webbing breaking or your garden folding in the middle...

I doubt you'll need the concrete if you cut a T trench for each anchor then bury metal tubes of at least half a meter, and ~50mm dia at least half a meter deep. A pair of car wheels would be a good alternative that won't lift out in a hurry.

It's worth a thought how you will mow the grass over your chain.

jk

It's more than sufficient by an almost hilarious margin. 

4.75t is the kind of load you might see on a steel tightrope that you tighten up with a bloody great big Tirfor.  You won't be getting anywhere near it with a slackline.

This might help.

https://www.ropebook.com/information/vector-forces/

So based on this roughly 600-900 kg at each anchor for a static 100kg person.

the shackle should be peachy.

cheers for the link

thanks everyone! I had visions of things snapping and injury occurring! Great to have some reassurance and the link was a really interesting read too. Cheers!