Data for Magnus
Information for Magnus.
I presume you are using the standard 4m x 6m tarps here, but I can send you the figures for the smaller 4m x 5m UNHCR tarps if required.
Regarding the suitability of available bamboo , I will refer to photo 1 below.
Bamboo "A" , from what I can see, may be too thin to use for the central 4 pole reciprocal frame units
( ideal would be circa 2 inches /4.5cms diameter) . However it could be used for the 4 outer frame units ( 3.5m lengths) that are not the main load bearers .
Bamboo "B" may be able to be used for the 4 pole central reciprocal frame ( 2.8m lengths). My only concern is the bamboo wall looks quite thick and while this is good for strength there are bamboo types that become very heavy per unit length, and therefore "flex" excessively. This can be easily checked by cutting four 3m lengths of this bamboo, and then overlapping them at a point just under a metre from one to make a reciprocal frame. Lash these 4 poles together and it should lift itself just off the ground in the centre by a few inches, as shown in the second pic (photo 2) below. If it bows downwards under its own weight it is unsuitable. You can double check this by getting 4 persons to lift the frame together at each corner. When it is horizontal.... the centre frame should be be slightly elevated and not sag. In an absolute emergency I would still use this bamboo but cut the frame size down and adjust the overlap accordingly to make it work; we can do this if required. Certainly this bamboo can be used for the 2 props needed for the emergency shelter.
I have included the diagram handbook that we use for assembly of all the shelters FYI.
Also the detailed spec for one of the other shelters ( single elevated) so you see what is available if required ( I have all RSK shelter types spec if needed).
The reciprocal frame roof concept is very simple and easily picked up by families. It is not dependent on skills or quality of lashings to build a safe shelter providing a simple checklist is made after assembly. Measurements are not critical to construction and with experience can be estimated ; they are mainly there to get a good fit for standard tarp sizes.
The emergency shelter, provides the basics for 5 persons as built, but can also be opened up to create a lift up awning on the "tarp only" side to improve living space. The "frame and tarp" side can be elevated a couple of feet onto small posts or a low wall to greatly improve living space.
After this introduction I will send you only what you require. I hope this is of some assistance.