BILS1 experiments

BILS1 is a cylindrical shaped flexible "bubble", height 2.0m and diameter 1.2m. Volume about 2250 litres,

The materials are not relevant at this stage and are not discussed. The storage is equipped with temperature sensors, hydraulic connectors, windows. holding loops, and other openings. This BILS1 will be used to get a first impression and a better understanding of its behaviour under water.


The BILS in the laboratory pumped up with air, Top and bottom are dome-shaped due to the air pressure. 

-> Lesson learnt: The shape of the device is not only defined by the shape of the materials. Pressure differences between inside and outside define the final shape.  But BILS are intended to be pressurless devices,


Thanks a lot: We are allowed to use the idyllic swimming baths "Zwischen den Hölzern" of the CIty of Zurich. 


First steps, the BILS is filled with water using the immersion pump visible on the rght side, then placed in the pool with a depth of 3.5m. 

Observations: The BILS is sinking to the ground, but as there are some air bubbles enclosed, the cylinder remains upright as on the picture. All connectors are loose, meaning that this is the natural behaviour of the storage. 

For safety reasons the BILS is not completely filled to make sure that inside and outside pressure are in equilibrium.

Lessons learnt: Air bubbles are useful to control the position of the storage. On the other side, it is not so easy to get air bubbles out of the storage. Must be kept in mind for the next versions. 


The expert committee is critically observing our experiments