Part of my process of prototyping exploration includes looking at various methods of collapsibility. While seeking methods of flat packing, I found various forms of water bladder tanks:

This onion tank is from a Chinese Manufacturer - Flexitank: "Onion tank is a folding environment-friendly collapsible water storage tank. It's widely used to solve water emergent supply for camping or when there is no fixed water storage device. The onion tank filled with water is in onion shape. According to client's demand, two types of onion tank can be produced, namely open style and with cover. The tank is made from thermoplastic polyurethane or PVC coating fabric."

A variety of manufacturers also create water bladders in different sizes and shapes: "Rainwater Bladder Tanks are an easy way to store, collect and reuse rain water. Constructed for a flexible material, these tanks are designed to feature a low, wide profiles. This design allows them to store large amounts of water in tight storage spaces, such as in basements, under decks, in crawl spaces, and in other areas where a traditional tank would not be able to fit."

I was inspired to look at different method of creating bags in more convenient shapes for storage, espcially in an oblong form that could be stored between houses, and stacked horizontally to optimize use of space. I examined different folding methods for flat packing, such as folding the bag into a sturdy lid, and rolling the bag. I also looked at different lid forms.

For support structures I considered flexible wire supports, steels frames, flexi-tent poles, and plastic panels. I explored these options using a variety of methods including sewing small scale versions of the tanks and using wire, polystyrene and wooden dowels to represent structural elements.



I learned that a solid lid that doubles as a support to hold the "bag" open, is the best method. Tent poles and panels are both promising options that I will continue to explore. I still need to examine the interaction point between the modules (overflow valve etc). The major downside to the options is the cost. these items are potentially very expensive and I don't know of any manufacturer in Arusha for this type of product.