So, here's the rough numbers for cardboard-and-ply-press mass deployments of the Hexayurt project. In this scheme, panels are made by hand, using a simple plywood press. The process works like this:
- A container load of cardboard, presses and finished hexayurt panels is sent out, with multiple containers of raw materials (hexacomb and facing sheets, glue etc.) following.
- If outdoor conditions are inclement (rain, dust) the finished panels are assembled into factory hexayurts, and the presses are moved inside.
- To make a panel:
- Lay down a sheet of facing material (kraft-paper backed aluminium.)
- Stretch out the hexacomb to form a 4' x 8' panel.
- Roll glue over one side of the hexacomb, then flip it over and stick it to the facer. Pins hold the hexayurt in the expanded form.
- Apply glue the other side of the hexacomb.
- Stick on the opposite facer
- Add to the stack of panels being worked on, and apply weight
- When you have 12 (or the required number) of panels in a stack, many refugees sit on the press, allowing the glue to set.
- The panel edges are then trimmed and sealed either with tape or by folding and crimping the edges shut with more glue.
- The hexayurt is then assembled.
$100 per panel press - two by fours, plywood, some metal rods or pegs. Assume three minutes per panel, with stacks of 20 or 40 panels being left in the press for half an hour to dry. Guess 20 panels per press per hour.
$4.50 for each honeycomb core, coming to say $7 total with panel facings and glue. But it could be more like $5 total.
- 100 presses = $10,000.
- 100 presses * 20 panels per hour * 12 working hours a day = 24000 panels per day
- 24000 panels * $7 per panel = $168,000 of cardboard etc.
- 24000 panels per day / 12 panels per basic house = 2000 houses per day.
- 12 panels * $7 per panel = $84 per house for panels.
- Assuming $16 of other bits (tape, etc): $100 per house.
- 166 square feet each, or shelter for around five people: roofs over 10,000 per day, assuming there are people to tape up houses and work panel presses.
Now shipping volume.
- A panel weighs about 7 lbs, between facings and core.
- A 20 ft sea container can be loaded to 40,000 lbs (up to about 50,000 lbs I believe)
- 40,000 lbs / 7 pounds per panel / 12 panels per house = 475 units per sea container.
- 475 units is shelter for about 2400 people, assuming 5 per unit.
So you need roughly four 20ft containers per day to keep the presses running. I'm not sure what that is in Chinook loads, but I think it's about 20 runs.
Assume the presses weigh 100 lbs each = 10,000 lbs of presses.
Both the presses and the core are heavy enough to be weight rather than volume bound for the shipping container.
So the first 20ft container ships with 100 presses and and as many panels as can be fitted in, to make the "factory" units. Panels fit 480 per full container (or 40 hexayurts per 20 ft container).
I think the approach is to send two to five 20 ft containers of panels or pre-fab buildings, emergency food, water purification tablets and panel presses. Then as quickly as possible get the panel presses going, and ship in the rest of the infrastructure packages.
What's interesting is the cost for 100,000 people comes out to be about $2 million, give or take, just for housing, and more like $4 m ($40 per head) with a very basic infrastructure package. I think those are quite attractive numbers, really.