Half box strainer / H brace thoughts

[gellis888]

I've seen half box strainers used in deer fencing for places where a full box wasn't necessary.

Do they have a place in sheep and beef fencing? Or does it just make sense to put a full box strainer in every time or put a strut in instead?

 

[jellybean]

What do you mean by a half box strainer, a shorter secondary post and a top rail which meets the main strainer half way up? If that is the case you will have saved half a post and possibly half a top rail but done exactly the same amount of work.
If you are happy that the half box is as strong as a full box then no problem. You seem to have answered your own question by indicating that in some places a full box strainer isn't necessary.
In reality a properly built strainer assembly will work, whether for deer fencing or for sheep and cattle. That could be a box strainer or a strutted post. Main considerations are having a long enough strainer post i.e at least 4 foot in the ground although bad conditions might need more, followed by top quality work on all struts or box assemblies. Not forgetting that on box assemblies the top rail should be twice the length of the height of the fence.

Fencing in these photos has been up for 32 years so far. It definitely pays to use top quality materials.

I will have said this before but the initial COST of materials and skilled workmanship is irrelevant; what is important is the cost of the fence per year for the next 30 years. So it is simple, decide how long you want the fence to last and spend your money accordingly.

 

[Fendt516profi]

Best I can do but think this is what he means by full box strainer
π
And this half box strainer H brace
|---|

 

[tepapa]

Half boxes are shite. Do it properly or don't do it at all.
There's nothing wrong with doing a proper angle stay. Like @jellybean says, don't skimp on materials, it gets a lot more expensive if materials/fence fails prematurely.

 

[jellybean]

Just to put things in perspective, I have 10,000 metres of deer fencing on the farm, all done by ourselves because fence erecting was my main business at the time. From memory material costs were about £3.50 at that time and supply and erect we would have been charging about £5.00.
So my cost for 10,000 metres was £35,000, spread that over the 32 years it has been up (and ignoring its remaining future life) and we have an annual cost of 11 pence per metre, or 15-16 pence if it had been supply and erect.
I have just started to replace some of the stakes this year so more difficult to calculate annual cost from now on.
I would say a good fence is an investment, a poor fence is a liability.

 

[Tubbylew]

I assume you mean these turkey perch type things, these were used at the time due to a lack of materials, and it shows imo, but I was only helping on this job. (Before anyone mentions it I'm off to beat myself with a strainrite easypull for hard stapling the end, a shame and burden I'll carry forever in my heart) also with materials being as expensive as they are it pays to get someone who knows what they're doing.

 

[gellis888]

Thanks @jellybean, @tepapa and @Tubbylew. Safe to say you've answered my question. I'm going to do my own fencing and deciding on how I'm going to do it. At the moment I'm trying to get some telegraph poles for terminal posts, creosoted posts for intermediates, box strainers for ends and double boxes for longer pieces and struts for direction changes. I've always been told boxes are the strongest?

Also nice stags @jellybean

 

[tepapa]

Thanks @jellybean, @tepapa and @Tubbylew. Safe to say you've answered my question. I'm going to do my own fencing and deciding on how I'm going to do it. At the moment I'm trying to get some telegraph poles for terminal posts, creosoted posts for intermediates, box strainers for ends and double boxes for longer pieces and struts for direction changes. I've always been told boxes are the strongest?

Also nice stags @jellybean

Take what your told with a pinch of salt.

How you build an angle stay or box will determine how strong it is. People that say boxes are strong really mean that they can't build a proper angle stay. The same people generally can't build boxes either but that's life.

Telephone poles are a good 'affordable' option for strainers, they won't last as long as new Creo strainers but do come in cheaper. 8' long is minimum length for strainers but go longer if your on good ground and can get them in. Ideally gate posts will be 9' too as even if it's level ground it'll be 1.3m out the ground so 1.4m in.
Use an 8' long strut, at 47cm or 60cm up on the strainer, depending which square of the nett you want to use, so it isn't in the way of tying off netting.
Then use a decent sized strut block. And I don't mean just a fence post. Use another strainer if it's soft ground or part of a railway sleeper. Use the thin telepoles cut to 4-5' that won't make decent strainers.

 

[ARW]

A normal strut can be just as strong as a box strainer, I’ve had a box strainer twist before pulling too longer of a length.
we only usually do box strainers in very wet ground, light Sandy land and some corners spring on and angles and slopes.
your strut block is important as your strainer, we knock a post in to ground level as a strut block

 

[gellis888]

@ARW @tepapa sounds like a post/strainer knocked in all the way for a block is the safest to guarantee a good hold. If I'm using an 8ft strut and strainer/post for a strut block, am I not using the same materials I'd need for a box strainer? If so, I guess it comes down to preference and time difference doing each (correct me if that's a stupid question)

 

[Bury the Trash]

What do you mean by a half box strainer, a shorter secondary post and a top rail which meets the main strainer half way up? If that is the case you will have saved half a post and possibly half a top rail but done exactly the same amount of work.
If you are happy that the half box is as strong as a full box then no problem. You seem to have answered your own question by indicating that in some places a full box strainer isn't necessary.
In reality a properly built strainer assembly will work, whether for deer fencing or for sheep and cattle. That could be a box strainer or a strutted post. Main considerations are having a long enough strainer post i.e at least 4 foot in the ground although bad conditions might need more, followed by top quality work on all struts or box assemblies. Not forgetting that on box assemblies the top rail should be twice the length of the height of the fence.

Fencing in these photos has been up for 32 years so far. It definitely pays to use top quality materials.

I will have said this before but the initial COST of materials and skilled workmanship is irrelevant; what is important is the cost of the fence per year for the next 30 years. So it is simple, decide how long you want the fence to last and spend your money accordingly.

That wouldve been CCA treated, cant get it now .

 

[tepapa]

@ARW @tepapa sounds like a post/strainer knocked in all the way for a block is the safest to guarantee a good hold. If I'm using an 8ft strut and strainer/post for a strut block, am I not using the same materials I'd need for a box strainer? If so, I guess it comes down to preference and time difference doing each (correct me if that's a stupid question)

Ye stupid question.

A box strainer is relying on the brace wires to hold tension and resist movement where as an angle is putting the force directly into the ground to resist movement.

(Not trying to pick on you here but your asking the question so it's directed at you).

I don't know how you plan to build the box but let's pretend you're using one wrap of wire and a gripple. Because someone taught you that way or you saw a pic on Facebook. Now your brace wire is doing the holding. One wrap will give you two wires with a braking strain of 600kg each so 1200kg of force at breaking point. And a gripple that will fail at 350kgs. Pull up 10 lines of HT wire to 150kg's and you've loaded 1.5t of force onto that box strainer. Now remember the gripple will fail at 350kgs so a quarter of the tension you've applied. Even without a gripple there's more tension on the fence than the wire can hold. Double your wraps so it will hold 2400kgs force your brace wire is still at almost half it's breaking strain. So you really need at least 3 wraps of 2.5mm ht wire for 3600kg of hold in the box strainer.
My point being, your saying a box is stronger or is preferable/preference but yet I have no idea how you plan to build it or what materials your going to use or how tight your going to tension your netting.

I also know someone who built boxes for 10 years and will probably never build one again now he's learnt to angle stay well on his type of ground (with the odd bit of footing or tying back where required)

 

[gellis888]

Ye stupid question.

A box strainer is relying on the brace wires to hold tension and resist movement where as an angle is putting the force directly into the ground to resist movement.

(Not trying to pick on you here but your asking the question so it's directed at you).

I don't know how you plan to build the box but let's pretend you're using one wrap of wire and a gripple. Because someone taught you that way or you saw a pic on Facebook. Now your brace wire is doing the holding. One wrap will give you two wires with a braking strain of 600kg each so 1200kg of force at breaking point. And a gripple that will fail at 350kgs. Pull up 10 lines of HT wire to 150kg's and you've loaded 1.5t of force onto that box strainer. Now remember the gripple will fail at 350kgs so a quarter of the tension you've applied. Even without a gripple there's more tension on the fence than the wire can hold. Double your wraps so it will hold 2400kgs force your brace wire is still at almost half it's breaking strain. So you really need at least 3 wraps of 2.5mm ht wire for 3600kg of hold in the box strainer.
My point being, your saying a box is stronger or is preferable/preference but yet I have no idea how you plan to build it or what materials your going to use or how tight your going to tension your netting.

I also know someone who built boxes for 10 years and will probably never build one again now he's learnt to angle stay well on his type of ground (with the odd bit of footing or tying back where required)

Thanks for explaining that's really helpful. I was thinking to wrap 3 times with 2.5mm and crimp it. What's the longest line of netting on flat ground you would pull up?

 

[tepapa]

Thanks for explaining that's really helpful. I was thinking to wrap 3 times with 2.5mm and crimp it. What's the longest line of netting on flat ground you would pull up?

If I built the end strainers well enough maybe 1000m. I wouldn't use length as a limiting factor I'd just ensure I'd built my end strainers to hold.

 

[jellybean]

If I built the end strainers well enough maybe 1000m. I wouldn't use length as a limiting factor I'd just ensure I'd built my end strainers to hold.

@tepapa is correct. If the strainer assembly is built properly then you can pull up pretty much as long a run as you want, the strength of the fence is in the strainer and the netting, the intermediate posts just aid in keeping the netting upright and give resistance to livestock pressure. Longest run of HT deer netting I have pulled between 2 box strainers is 800 metres with 11 turning posts in that run. Greased the backs of the turning posts, did the pull last thing one day and left the clamps on, next morning could pull another 9 inches as the netting had moved round the turners. On long runs like that you need to keep walking the line and shaking the slack out or you can end up tight where you are pulling in the middle but slacker at the far ends.

 

[gellis888]

@tepapa @jellybean when I've put the first fence line up I'll put a picture up here and see what you think (for better or worse). Thanks for the advice!

 

[TBradbury]

@tepapa @jellybean when I've put the first fence line up I'll put a picture up here and see what you think (for better or worse). Thanks for the advice

He sent me a couple of photos of the turner posts ‘gorgeous George’ did recently, pretty impressive for a first time!