Concrete Fence strainers

[crofter 65]

Hi, when I was on holiday recently on Orkney I saw a lot of people used concrete fence strainers and was wondering about the pros and cons of these as the timber ones don't seem to last very long, I have a few very rotten ones that are not that old.
I was pondering making a shutter and making my own. any thoughts comment would be appreciated.
TIA.

 

[Cowcalf]

they do not give if caught just snap, but great so long as you have capable drivers

 

[upnortheast]

Drop a few bars in the shutter, should be fine

 

[crofter 65]

I am not bothered about snapping them as they wont be to many passing through and I would add some bar to the shutter, I was planning making them 8" square and concreting them in.