I’m hopeless when it comes to thinking about 3D objects…!

So, if I had a 2-pole symmetrical tunnel tent, such as this one:-

If I had it pitched on a large flat board which had a hinge across the middle, what would happen if I folded the board in half? Would the tent neatly concertina between the two sections of the board, or would something nasty happen?

Poles would snap.

Hmmm I think it’d be fine, provided:

There are just two poles, one for each arch
AND they are only held in place by the tension on the pitching
AND they can freely swivel at the points where they meet the floor
AND you only peg in the end parts

I don’t think it’ll be quite as neat a solution as you imagine though as you’ll have a big bit of tent between the two parts of your board which would stop it folding completely together.

The poles would clash if they were to fold in at the same time

Is the hinged centre running down the length of the tent or across its width?

I reckon that if it’s across the width then there’s a good chance it’ll fold in half quite nicely, well at least until the poles touch and then that’s as far as it’ll go so it’ll not fold completely. Lengthways and I’m agreeing with matt_outandabout, you got bigger problems with the poles.

You might need three bits of board – a centre one around 15cm across, with the two larger ones hinged to it. Picture a tall, thin “U” shape when it’s folded. The spacing of the centre piece would accommodate the material of the tent.

Of course, you’d still have to thread the poles once unfolded.

Why? Do you think it’s something you might do?

Yes, it would be folding across it’s width. So if it was stretched taut by pegs at both ends and not down the sides it might work.

I was thinking it might need a bit of depth in the centre as suggested by Scotroutes. What do you mean about threading the poles once unfolded?

Would the sides spill out when folding? Also, what length would the boards have to be – would they have to be longer than the tent to accommodate the height of the tent?

I think most trailer type tents which fold have the bottom of the ‘hoops’ meeting at a pivot point. However, the tunnel tent’s poles are pretty much parallel, and spaced apart from each other.

Ah – I see what you’re getting at. If only the front and read are actually attached to your folding board then the oled section would concertina into the middle.

I think you might struggle in that case. If the width of the centre board is less than the distance between the two poles then they would effectively “creep up” the sides of the U as it’s folded. I was assuming you’d fold the tent and then re-thread the poles once unfolded again.

Can I be the first to ask – “why?”.

Sounds like a homebrew roof tent to me

If I had it pitched on a large flat board which had a hinge across the middle, what would happen if I folded the board in half?

You would have an uncomfortable nights sleep.

Yep, that’ll be fine

Imagine cutting the tent in half and letting both sides collapse left and right. That’s exactly what would happen.

Trail_Rat has got it – a roof tent. It was just a brief thought, and I’m not sure if it has any potential. If it’s going to be awkward to fold or secure then it’s probably not worth the hassle.

I’ve got a 2-pole tunnel tent (but not a roof rack as yet). When camping with a van I’ve sometimes inserted the poles before leaving home, then laid the tent flat in the van. At the camp site it’s then a matter of pegging one end and pulling the other end out and securing with another two pegs – it can be up in seconds, although it needs additional pegs to fully secure it.

Maybe you should look at inflatable tents.

Or even better for his use a pop up tent 🙂

You cant do it with two flaps.

The problem you have is the hooped poles are fixed height and width. If the pole is mounted halfway up a flap they cant fall inwards as they wont fit into the distance from pole base to hinge.

You might manage it with three flap.. the centre piece the size of the rectangle on the ground between the poles with the other two flaps the same size or smaller.

However i think you’ll still have a problem as the poles are thd same size they’ll potentially clash and the gap between them needs to allow enough fabric for one pole to lie flat with the other one folded over.

Thats all in my head but i’m pretty sure its right and a non starter.

Cougar – Moderator
Imagine cutting the tent in half and letting both sides collapse left and right. That’s exactly what would happen

Except the fabric would prevent that happening if you unpeg all the pegs the poles will either both fall in and probably catch on each other or both fall left or both fall right

We’re getting into origami territory. 🙂

Except the fabric would prevent that happening if you unpeg all the pegs the poles will either both fall in and probably catch on each other or both fall left or both fall right

Assuming the ground pegs remain and there’s an absence of guy ropes, it’ll all fall outwards.

If the pole is mounted halfway up a flap they cant fall inwards as they wont fit into the distance from pole base to hinge.

As it folds inwards the now-excess material in the centre will allow the poles to fall outward.

No it won’t.

The distance between the bottom of one pole at the apex of tuther pole is fixed in tension by the fabric. The distance between the bottom of the poles is fixed by the board. The height of the poles are fixed also. Thats a pretty rigid structure.

If you go back to the two flap method that would actually work if you had no fixings between the poles that would allow you lay the poles together and effectively concertina the fabric in the middle.

Edit

As it folds inwards the now-excess material in the centre will allow the poles to fall outward.

This.. but you need to remove the pegs between poles

This.. but you need to remove the pegs between poles

I’m not convinced that the distance from the tent peg insertion to the tent apex would increase as the tent folds inwards. I can see your point, that as you fold the tent effectively changes from one rectangle (I know it’s a trapezoid, I’ve simplified the shape a little..) to two opposing parallelagrams, the resulting diagonals would increase the length of material needed, but as I run it through my head I’m not convinced that the distance between the relevant fixed points (tent pegs and pole insertion at base, pole apex and apices of the various arcs between laterally opposing tent peg insertions) would increase..

You can break it down to two parts.

Chop the tent in half and remove a half.

The remaining pole is still standing upright held in place bythe one peg of the porch and the two pegs in the centre of the tent.

No matter what you do with that half of the tent you need something to give.

The remaining pole is still standing upright held in place bythe one peg of the porch and the two pegs in the centre of the tent.

you clearly have not pitched a tunnel tent recently.

if you cut the tent in half i assure you it will fall over to the side with the pegs by the porch due to the tension in the fabric.

*source – the benny hill show of me errecting our hoolie 2 every day on every surface bar grass during the month of august

Now if the tent had been showing with the guy lines at the pole attached and pulled taught away from the porch – different story. but as shown the pole will fall to the porch.

I’ll concede there maybe enough length gained from the curve straighening/give in the fabric.

However I’m still going with a three flapper being the mist lukely to work.

But any kindof faffage up high would make it more difficult to build than just putting it tigether traditionally on the ground.

The remaining pole is still standing upright held in place bythe one peg of the porch and the two pegs in the centre of the tent.

Unless I’m just not seeing it in the picture, there are no pegs in the centre of the tent. Just porch, tail and at the poles. If you cut it in half the former middle of the tent will be flapping about.

IMO it’ll be reet.

At least the folding tent part – how you get in/out and how much wood will support you effectively are a different kettle of fish.

If the fold point was slightly off-centre, it would stop the poles from clashing.

Two hinges a few inches apart?