Igloo building: blocks, sheets, triangles, volumes, areas and glue

Following on from preparation and initial mincing, the next things to decide on where how to create the chicken wire skeleton, and how the blocks would be attached to the substrate given the extra complication of a white sheet in between the two.

Chicken wire dome

Chicken wire will be great as a skeleton, as it’s relatively easy to shape, but can still be nice and sturdy if you need it to be. The mesh structure will be really useful for anchoring it into the ground, and attaching the coverings, too.

However, it only bends nicely around one axis at a time, as it barely compresses or expands as a sheet at all. That means making cylinders of chicken wire and expecting to be able to stack and bend them into a dome is not going to work. What I’ll do instead is to cut 16 equally sized isosceles triangles, chain the bases (b) together into a loop, then stitch neighboring long sides (l) together, eventually joining all the acute vertices at the top of the dome.

It’s pretty likely this won’t hold its own weight particularly well, so I may need a single vertical pole in the middle of the dome.

Attaching the blocks

The polystyrene blocks must be secure (because of the wind), quick to put on, and easy to take off. And as the polystyrene itself is awkward to work with, I’ll do as much of the hard work as possible before leaving for Nevada. The best solution seems to be to attach the blocks onto strips of white fabric, measured to fit around the igloo in courses. These strips will be useful in keeping everything together during transport, and make it super easy to attach and detach the blocks once on the playa.

I wasn’t sure about how to permanently bind polystyrene onto fabric; I wasn’t sure until I found This to That. Hot glue!

As for attaching the fabric strips to the sheet and chicken wire underneath, I’m not sure. However, I do know that it’s a much easier problem to solve than dealing with the blocks.

Next up: trying to make custom blocks of polystyrene, working out how much chicken wire I need, finding suppliers and finally the pre-build prep work!

Posted via email from An Englishman in San Francisco

Igloo building: preparation and initial mincing

Burning man is only 6 weeks away, and my highfalutin plans to build a polystyrene igloo on the playa are looking ambitious at best. So, fueled by some Arctic architecture brainstorming with my sister, this weekend I began making plans for how I can make this work.

Size

My first pass at sizing was that I’d like to be able to stand up in the centre of the dome (so 195cm inside radius), and that the walls should be around 20cm thick so that you get some real thermal insulation benefit during the hot day and cold night.

Unfortunately, this works out at being over 5 cubic metres of polystyrene. That’s a lot, considering we need to fit it in the van to ship it in and back out, along with hundreds of litres of liquid nitrogen, bikes, water, people, a geodesic dome, etc..

Scaling this back to 180cm at the zenith, with 10cm thick walls, it comes out at 2.15 cubic metres of polystyrene, which is a lot more practical, although still pushing what we can realistically take.

Design

I got really inspired by this old 1940s Canadian public information film about traditional Inuit igloo building (video doesn’t work in the UK, unfortunately…). I’d assumed igloos were built much like houses, with interlocking blocks going on top of others in courses. In fact, it turns out that the best construction method is to spiral upwards, round and round from bottom to top, so there’s effectively only one course of blocks which loops round on top of itself. This means you never have that awkward first block in a course which would have nothing to butt up against. By spiralling up, you always have a block below and a block to the side to nestle up to.

Using this method, one man can create a 6″ high shelter in less than an hour, using nothing the stuff he’s standing on.

My initial thoughts were to mimic this proven design very closely, working out some way to bind blocks of polystyrene together that would be easy to detach at the end of the week, ready for shipping back to SF and reuse in the future.

However, after some thought, I think the traditional method just won’t work for polystyrene. Firstly, the stuff is so light that it needs no encouragement to fly off at the merest hint of a breeze. Secondly, while snow blocks can be mushed up and mashed together, naturally binding together as they re-freeze, polystyrene just doesn’t behave that way; each block would have to be manually, laboriously anchored to its neighbours. And I didn’t know what that magical reversible binding was going to be… Thirdly, you can easily cut a doorway into a finished igloo, but cutting holes in the polystyrene would dramatically weaken the structure and produce loads of non-biodegradable, impossible to catch white beads flying everywhere in the wind.

So, the design I’m going for is a three stage process:

1. a chicken wire skeleton to the desired internal size, complete with doorway, anchored into the dirt with rebar
2. a white sheet over the chicken wire
3. blocks of polystyrene attached individually to the chicken wire, with some reversible binding

The idea is that the wireframe will be free standing, and give us a substrate to build on. The sheet is to fill in the gaps between blocks, keep the wind out and complete the “all white” effect. If we manage to get the blocks nestled together closely enough, very little sunlight will make it through directly to the sheet.

What next?

• How best to create an igloo shape out of chicken wire? That stuff is pretty horrible to work, especially with 3D curves
• How to get / create polystyrene blocks? I’d like to make them myself if possible…
• How to attach the blocks to the chicken wire, through the sheet
• How big should the blocks be? Is it practical for them all to be the same size?
• How much will it cost?

Posted via email from An Englishman in San Francisco

Passport stolen!

… by bureaucratic inefficiency.

As soon as I got back to the UK, I sent my passport in to the US embassy in London to try and get my visa stamp, hoping to get it back in time to shoot straight back to the west coast. Unfortunately, my optimism for quick and easy processing was once again ill-placed, and I still haven't got my passport back.

The embassy can't give me any information, good or bad, so I don't know how long it will be before I'm able to travel. Although I'm increasingly inured to leisurely paperwork processing by now, this delay has been a particularly frustrating one; I've missed Christoff's whole family visiting San Francisco, Alex's birthday BikeBQ (first non-ironic sighting of the <blink/> tag in a while , a mini-festival this weekend to the north of the city, Pat's bachelor party and a bunch of other bits and pieces.

Currently scheduled to get back to San Francisco on July 28th, although I've already had to push my flight back twice – that plan might change!

All my Yosemite pictures

Are a Flickr set here: http://www.flickr.com/photos/69148053@N00/sets/72157620959491413/

Yosemite trip

Just before flying back to England, some friends and I made a trip to Yosemite for the weekend. We headed out there after work on Friday, setting off at around 7pm with the car full of enormous sandwiches, bourbon and sleeping bags.

The 200 mile drive took about 4 and a half hours, including a couple of stops, so we arrived pretty late, just wanting to set ourselves up and get some sleep ready for the big day to follow. However, before we could do that, we had to empty all food and smelly stuff from the car, or face a $5000 fine for tempting bears into camp; there was a special bear proof locker outside all the tents into which we threw the aforementioned monolithic sandwiches, chocolate and toiletries.

After a few hours sleep, we woke up at about 6:30am, to be met by this view:

Note the angle of the trees – I was craning right back just to get that cliff in the viewfinder… And that started a day of incomprehensible scales and impossible vistas.

The plan was to hike up Half Dome, a mountain nearly 9,000 ft high. Although the campsite was already roughly as high above sea level as the tallest mountain in Britain, we still had a 5,000ft climb up to the summit. To make this clearer, if Robert Wadlow, world’s tallest human, was as big as Half Dome, we would have been camping near his crotch, while Ben Nevis would be up to his belt. Meanwhile, the Eiffel Tower would be halfway up Wadlow’s shin, or at the shoulder of Gul Mohammed; world’s smallest man. Basically, although we were starting high, there was still a long way to go.

After bagels and cream cheese for breakfast, we set off. I was carrying 5 litres of water, a sandwich the size of the Indian subcontinent, a few Snickers bars, a hat, a jumper, waterproof hat and waterproof trousers, as “the weather can turn quickly at high altitudes”.

I quickly came to realise that I’d made a grave error. As we moved up out of the valley on the Misty Trail, and into the sunlight, it became obvious that it was going to be a scorching day, and that I had about 10kg of useless on my back. Undeterred, we pressed on up and to the side of Vernal Fall.

By this point, things were getting a bit warm, so the blast of misted snow melt from this waterfall was very welcome!

From Vernal Fall, it was on and up to Nevada Fall; an enormous waterfall onto slanting rock. 20 feet before the fall itself, the river looks completely innocuous and harmless – quite a transformation!

By the time we reached the top of Nevada Fall, it was around 10:30am, and we were roughly halfway to the summit. The next hour or so was gentle enough climbing up through pine forests, with the imposing bulk of Half Dome itself appearing to our left.

At about 11:30am, due to a few too many Snickers and energy bars, and burgeoning sunstroke, I thought it would be a great idea to run the rest of the ascent, so off I shot, aiming to get to the summit for lunch. This actually went better than could be expected, and although I was basically dying, I did manage to catch up with the leaders of our expedition (who had continued while we were messing about at Nevada Fall).

As we neared the final ascent – the side of the dome itself – we could see a little line of ants on the side of the huge lump of granite; ants that gradually turned into tourists from Nebraska.

Now, I’ve never had to queue for a mountain before. And although in principle I’m a big fan of The Great Outdoors being popular enough for there to be congestion here and there, the fact that you were expected to wait for an hour and a half before starting the final ascent was a bit strange to me…

Still, I sat and took an inconsequential feast from a sandwich the size of Michael Jackson’s remembrance book, and waited for everyone to catch up. By now, it was really hot. We were way above the treeline, so there was no shade, and the white granite was bouncing back the intense sun from all angles.

The final pull up to the summit was very steep bare rock – maybe a 55° slope – so a pair of metal cables have been run to the top, the idea being that you pull yourself up to the top between the cables. It was this “between the cables” bottleneck causing the queue, so we decided to go up the outside of the pair, using just the one cable and bypassing the delay.

The summit was barren and indescribably hot. Hot, hot, hot. We heard afterwards that it was 110°F.

The views from the top were amazing; the globular granite mountains seemed so extra-terrestrial to me. But it was the sheer 1,500ft drop off the front of the dome that was most striking.

After an hour or so mincing and recovering on top, we started down the mountain. The descent proceeded without incident, stopping only to refill water (making it 7 litres that day, in total), and get a couple of pics of Half Dome with Nevada Falls in the foreground.