Part of background to the Interceptor Trashfence - Team Gaia tech report

 1.1.4 Problems linked to the Trashfence

It is emphasised by Slat (2022) that the Trashfence is still an experimental system. The operation of the Trashfence was not the final product of The Ocean Cleanup which shows that there is still more work to be done in improving the current iteration of the Trashfence. As the Interceptor Trash Fence is still a relatively new concept that was put to test recently, it is not the best in terms of efficiency. When it was trialled by facing a tsunami of trash, it gave way as there was too much trash and as seen in figure 2 the fence was unable to withstand the forces, some structural damage was also suffered during the process. This leads to trash flowing into the ocean affecting marine life which will also eventually affect humans too. When trash flows into the ocean, the water will be filled with bacteria and contamination resulting in marine life not being able to survive in these conditions.

 Figure 2

Trashfence failing

Note. Picture of the structural failure of The Ocean Cleanup Trashfence.

1.1.5 Functions and Systems

The interceptor Trashfence is a custom-engineered steel screen, chain-link fence that traps rubbish and is designed specifically for flash flood settings. The design was greatly motivated by avalanche protection systems. The construction, which is linked to the river’s banks and bed, collects waste and debris throughout its entire length for disposal. For optimum effect in heavily contaminated and difficult-to-reach areas.

According to Slat (2022), the construction of the Trash Fence consists of 6 metal support beams, 8 metres high, installed directly into the riverbed as seen from figure 3. A customised chain-link steel mesh fence is installed at the bottom across the support beams spanning 50 metres and 3 metres high to collect the rubbish. As we learn more about the design, the height can be gradually increased for better efficiency. As the width and height of the fence is customisable, this fence can be placed in any river around the world regardless of its size.

 Figure 3

Size comparison

Note. This picture shows the size difference between an average man as compared to a beam of the Interceptor trashfence.

The Trashfence is installed before the flash flood occurs which ensures that construction of the Trashfence is stable when built into its dry riverbed. It is further supported with metal wires connecting the metal support beams to the riverbanks. As seen from figure 4 the Interceptor Trashfence is a chain-link fence, as the river flows through the fence, it traps the rubbish and is designed specifically for flash flood settings. The design was greatly motivated by avalanche protection systems. The construction, which is linked to the river’s banks and bed, collects waste and debris throughout its entire length for disposal. For optimum effect in heavily contaminated and difficult-to-reach areas.

 Figure 4

Trashfence in action

Note. The image shows the trash being stopped by the Trashfence as the river is flowing through. 

In terms of its operation, Slat (2022), explains its concept as a simplicity. Once a flash flood occurs, trash will flow together with the flow of the flood. The Trashfence acts as a barrier, filtering the trash from the river whilst allowing the river to flow through the Trashfence. This process retains the trash collected within the fence until the water level drops down where the trash will be excavated manually.