Munro height fence

[Knoxfield]

I have been asked to price for a fence that will be up to 950m above sea level, where the average winter temperature is zero degrees! The mountain can still have snow on it right in to June.

So what I'm asking everyone is, what type of fence and what materials would be the best for the job? metal or wooden post? High tensile or Mild Steel?

 

I would much appreciate people experiences and opinion.

[Goaty]

0 C? I wouldn't worry about. Unless using gripples which people have commented ice up and release the tension grips. I've never used them.

From the alpine terrain I've experienced, on holidays and the structures I've seen, I think wood or galvanised steel products should be fine it will only be water not salt and if frozen the air will be dry with the moisture spending more time locked up in crystals. Boggy wet conditions and salty places will be the worse for material deterioration.

 

I known the sponsors of this site export a lot to Russian states which have the conditions you mention. High tensile will be far superior if use can get fairly straight longish pulls.

 

If you can't use a mechanical post knocker I assume this will help you narrow your post choice. Maybe clipped or staplelok if you are in Europe.

[tentman]

Gidday (from New Zealand).

 

I haven't done any what we call "High Country" (900-1500 metres) fencing for 30 years or so, but back then there was quite a debate about wether 2.5 HT or low tensile No 8 (4.0mm) was best, this was because the earlier HT's had quite a few breaks believed to be due to extreme cold.

 

Nowdays I still get out in the High Country frequently hunting rather than fencing, and all I see is 2.5mm HT, usually 7 wires with a barb on top, H5 125mm treated posts at 6 to 9 m spacings with 2 or 3 steel Y posts (we call them "waratahs")  between.    All end strainers box stayed, often doubled up (two stays one after another) and usually turning posts box stayed in both directions too.  In extreme terrain where all gear is flown in some of the guys are using all steel posts as they can be driven by a petrol "rhino".

 

Cheers

Foster

[West Fork Fence]

We generally see winter temps in the -20F range.  Summer temps are always over 100F.  The only weather related failures we see are posts that have heaved due to the frost cycles, and that's only where do it yourselfers or crooked contractors haven't buried a post deep enough.  No wire or gripple failures due to weather that I can speak of.

[Steffens]

Here in Norway this is a normal situation. We can have 10 feet of snow and minus 30 degree of frost. Due to mountain pasturing we have a lot of experience.  First you must study the terrain, is it a flat plateau or a hillside? If you follow the direction of downward slope along with where snow pressure is, you have little problem. If you have to fence across in a snowy hillside, you are in trouble, and may have to erect in such a manner that you either dismantle the fence before the snow, or loosen the lower staples to allow snow to get through. Needless to say the fence should be mounted on the post at the side where snow comes from.

 

Use a HT steel fence and allow a small slack to compensate for steel contraction in very low temperatures ( 0 degree is nothing).

Unless you have access in situ at rockdrilling equipment, we would use  tannalized wooden posts. Predrill hole with 1" extra space round the post. After knocking it down fill the cavity with small sharp gravel, rocks, or knocked up bricks or roof panes. Bang them in around the post with a sledgehammer.  When frost goes into ground these bits will be pressed into the wood and lock it in place, otherwise the ground may

"spit out" the post or dislodge it.

Costwise it should be the same as usual with the following additions: 1) the cost of transport to site, 2) extra work or time taken as a result of a possible difficult terrain, including postfixing in bedrock or in steep hills.     Best of luck!    Henrik Steffens, Norway.