Thursday, December 16, 2010
Monday, January 18, 2010
“My goal is pretty simple: by the time I die, everybody in the world has a place to sleep and a bowl of rice a day.”
- Vinay Gupta, creator of the Hexayurt
Vinay’s design is simplicity itself. Twelve sheets of insulated board, some tape and a utility knife is everything needed to construct a shelter. Hexayurt.com has videos and links concerning the Hexayurt. I believe that his target area of usage is pretty much arid lands. Coming from just south of the 45th parallel, our fall and winter seasons can get pretty wicked. I think that the Hexayurt design needs to be beefed up a bit for conditions found in say, China.
The Hexayurt project is open source, that is, no patents, no copyrights. The whole project is there to find solutions to housing the millions of people who do not have any shelter.
It is more than feasible that the general principle of the Hexayurt can be expanded so that materials and a trained crew can be airlifted into any disaster area and shelters be quickly built on site. One distinct advantage the Hard Shelled Hexayurt (HSH) has over a tent is resistance to Ultra Violet (UV) deterioration. Because of this UV resistance the life expectancy of the Yurt can be expressed in years rather than months. If the design is carefully thought out, once built the HSH can be disassembled and stored for future use.
As with the original design, the HSH is based on the panel concept. A typical wall panel can be seen in the illustration below.
The stiles will be rebated on both faces to accept sheet stock probably ¼” exterior for the outside. If the host country has a ready supply of gypsum board then the inside panel could be drywall. Drywall has the distinct advantage of being inexpensive, ridged, and fire resistant. However, gypsum is very heavy and would greatly add to shipping costs. If gypsum board is not available locally, then the stile/rail profile would need to be changed to accommodate the extra plywood used as substitute for the drywall. All rails, stiles, studs and bracing would be Versa-Lam® or BC rim board ®. One thing that is not shown on the detail is that each beveled face of the stiles will have bed rail hardware installed for assembly purposes.
Bed rail hardware is basically a tab-A-into-slot-B technology. It is the perfect method of assembling the wall and roof panels together. Utilizing BRH fittings will allow a tight secure join between panels.
The construction of the roof is similar to that of the wall panels, however in order to reduce the amount of waste, the panels will be cut from the offal from the wall panel stock. The flooring could be made out of custom built BCI joists. Possibly the flooring could be constructed of a plywood/hexacore sandwich.
Windows could be manufactured using vinyl glass slides placed in door lites. Doors could be manufactured using Versa-Lam
There are three obvious configurations to how the HSH system could be delivered.
· All of the sub-assemblies produced at the mill level and ready to assemble.
· All of the components milled and sheet stock pre cut and ready to assemble
· Rudimentary machining of the lineal and sheet stock being done at the mill level and then completely processed on site.
In the first example, because everything is pre-manufactured, assembly of the sill plate, rim joist, body and roof are quickly completed. The roof/wall assembly would be snapped together and placed on the sill plate completing the structure. As a result, the people who most need shelter would receive aid in the shortest time frame.
The down side is that labor is expensive and the cost per unit for the hosting country would be greatly increased.
In the second case, the labor cost of the mill would be greatly reduced and on-site labor/equipment expenditure would slightly rise. Assembly structures would need to be constructed. Power would have to be supplied either through local availability or portable generators of sufficient capacity to run the small electrical tools, and a compressed air system needed for final assembly.
In the final case, labor cost to the manufacturer would be at its lowest level, however, the training, assembly, and equipment requirements on the host county would increase significantly. In order to complete the beveling of the structures panels, heavy (electrical) draw equipment would be required thus requiring more energy. More skilled labor would have to be trained in an environment that demands immediate results, and can ill afford time lost.
Allow an examination of the second option.
The required equipment for assembly of the HSH would be:
· A building with three work stations
· Available power (Local or Gen-set)
· Air compressor
· Staple guns
· Glue applicators
· Small routers to set in the assembly hardware and pre hang doors
The first work station would be fixtured to hold wall elements so that they could be glued and stapled. The second station would be fixtured for the roof panels. The third would be for pre-hanging the door assembly, the attachment of assembly hardware and for cutting out the RO for the doors, windows and stove pipe.
Hurricane Katrina taught some very hard lessons. In its wake, the storm left thousands of people homeless. Travel trailers were available to the storm victims; however they were undeliverable due to a total collapse of infrastructure. From now on out, emergency aid will have to transcend infrastructure. Methodology will have to be developed that will allow aid workers to access those that need and implement those changes. Using the concept of Force Multipliers, a work force could be quickly trained in the disaster area. In a worst case scenario such was experienced after Katrina or more recently the earthquake in China, access to survivors is limited. The training team could be brought in via helicopter. The HSH materials could be brought in on pallets dropped from a military cargo plane. Five individuals would be selected from the survivor population and would be trained over a three day period on the construction techniques for the HSH. On the fourth day, that crew would begin to build autonomously. Another shop would be set up and the three day training cycle would be repeated. If 25 shops could become operational, by the end of three months, over one hundred thousand people would have a durable shelter.