Stress Testing the Ocean Cleanup System



In September 2018, The Ocean Cleanup in conjunction with partners including AGRU, launched the innovative ocean cleanup system —a 2,000-foot-long large diameter pipe outfitted with a submerged skirt, an array of sensors, solar-powered lights, cameras, and GPS. Its purpose? To clean up the so called Great Pacific Garbage Patch, halfway between Hawaii and California – an area twice the size of Texas with 80.000 thousand metric tonnes of floating plastic, trapped by oceanic currents that are converging in this area.

In today’s podcast, we will discuss how polyethylene came to be the material of choice for this extreme application, where the project stands now, and what kind of metrics The Ocean Cleanup is analyzing during this test.

Joining the podcast are Yuse Lajiminmuhip, technical copywriter at AGRU America, Melissa Grace, VP of AGRULINE at AGRU America, and Henk van Dalen, project manager at The Ocean Cleanup.

Transcript

Yuse Lajiminmuhip: Hello and welcome to The AGRU America Podcast. I am Yuse and today we’re discussing Ocean Cleanup System 001, a 2,000-foot-long large diameter pipe floating in the Pacific Ocean and acting as an artificial coastline that will help collect trash. Join us to learn more about this proof of concept and where the project stands today.

Announcer: Every month the plastic experts at AGRU explore how geosynthetics are changing the world around us. Discover more about AGRU at agruamerica.com or by calling 1 (800) 373-2478.

Yuse Lajiminmuhip: Joining me today are Henk Van Dalen, Project Manager at The Ocean Cleanup and Melissa Grace, VP of AGRULINE at AGRU America. Welcome Henk and Melissa.

Henk Van Dalen: Thank you. Thanks for having us.

Melissa Grace: Yes, thank you Yuse.

Yuse Lajiminmuhip: Question for you, Henk, can you share a glimpse of what it was like during the early stages for The Ocean Cleanup system? When did polyethylene become the prime contender?

Henk Van Dalen: Well, The Ocean Cleanup consists as a company for 5 years now. We actually rather refer to ourselves as a project than a company because the ambition is, how do you say, make ourselves out of business because once we’ve completed The Ocean Cleanup then The Ocean Cleanup as a project is also completed. So, it was funded in 2013, there was then some exploration phases which actually in 2014 resulted in a feasibility study issued by Boyan Slat, supported by various scientific members and this actually proved that an ocean cleanup was viable. This concept is different from what we had then but it was based on a passive system which basically did not chase the plastic through the ocean but let the ocean do its work and, in that way, collect the plastic. Now in 2015 the focus shifted to really researching the problem itself, like how big is actually this Garbage Patch we are looking at, how does plastic behave in the ocean, and this gave us significant findings which also initiated the 1st scale model testing in that year. Now, the North Sea prototypes are concepts we issued in 2016 and it was in May 2017 that we actually froze the concept design at what we are developing today, and this is also the concept which included the polyethylene floater in it. There were various concepts we evaluated throughout that period but what once we went to a floating passive system which was not connected to the sea floor, that’s the moment HDPE pipe really became the preferred element for the floater object.

Yuse Lajiminmuhip: From the sounds of it there weren’t really any alternatives once the design became this floater system?

Henk Van Dalen: In the begin period we did do some various testings on the North Sea, one of them was an oil boom configuration, it’s more floating compartments made of rubber material and this was connected to the sea floor. This was actually the 1st prototype we did, this gave us useful insights also that this was not the suitable solution. We did look at other concepts which included, for example, some steel truss or aluminum items but when we really developed the floating concept you’re looking at today it was very evident that HDPE pipe was the best way forward.

Yuse Lajiminmuhip: Melissa, could you describe some of the properties of the pipe used in The Ocean Cleanup system and what makes it well suited for this kind of application?

Melissa Grace: We knew based on the feedback that we’d received from The Ocean Cleanup team our pipe was to be the backbone of the cleanup system. AGRU’s challenge was to try to identify something that could be utilized to be strong and durable, while the application for the pipe being utilized by The Ocean Cleanup is not your traditional application, there’s no internal pressures created, the external pressures and/or stresses that the pipe will see are in some ways far more challenging. The pipe is going to withstand, in this application, wave action, UV radiation, natural forces of nature to include significant storms. HDPE pipe was a very flexible solution. This is something that a polyethylene pipe would be able to provide in application versus other technologies that potentially The Ocean Cleanup looked at during their design. Last but not least, we also utilize a special kind of resin called PE100-RC and this is very critical for this particular application as well as it provides additional long term performance and protection. This is a modified PE100 but, again, the main technical advantage of the pipe has been proven in laboratory conditions and also in full-scale applications is the extension of service life and the durability of the pipe in application.

Yuse Lajiminmuhip: In what ways did The Ocean Cleanup collaborate with AGRU in developing this system? I know that the pipe forms the backbone, the foundation of the system, and I know there are some other parts that are attached to it, how did you have to collaborate with AGRU in getting these things together?

Henk Van Dalen: Well, the collaboration with AGRU, first of all, was very good and positive and what you actually say, a collaboration in itself. It was during the concept-select phase that there was already some information sharing going on. However, when we froze the concept we really started developing, how do you say, more in detailed market research to see what the options available were for suppliers and also the dimensions and quantities we were looking for, and it was during this phase that we came into contact with Albert Lueghamer, which really has been a great support to the project. We had some early introduction meetings with him also exploring what is known about HDPE pipe and also the unknown we’re entering into because we are the first project worldwide which is actually using HDPE in a dynamic application out in the ocean as we are doing. So, there a lot of unknowns, and there are still. Sharing information with the AGRU team was very useful in that phase to not only, how do you say, sharpen our concept a bit more but also to understand where the capabilities are of AGRU itself and it’s actually doing the whole project. This collaboration continued, the scope was increased to also add bollards and certain other elements of the pipe to the scope of AGRU and it really was this working together, developing testing programs together and sharing information that was part of the success of The Ocean Cleanup so far.

Yuse Lajiminmuhip: The project is underway now correct?

Henk Van Dalen: Yes, that is very much correct. We launched the system on the 8th of September this year, that means she sailed away from San Francisco area. We then went to a location about 300 nautical miles offshore, this is where we conducted what we call the Pacific Trials. This was 2 weeks of testing to really understand you know how the system behave with regards to the models we’ve been using, how is the system in its survivability of performing and also testing other equipment that is attached to the barrier. Now, this 2 weeks of testing was quite rigorous but the results were very positive so we completed them about 2 weeks ago and it is as of today we’ve just arrived in the great Pacific Garbage Patch yesterday. So this is actually the location where we’re going to deploy the system for a minimum of a yearlong operation and today coincidently is the first day that we’re actually a live operational and staring to collect plastic.

Yuse Lajiminmuhip: Wow, that’s amazing. So, I’m guessing the timeline for the next few months is actually a timeline of 1 year so, it’s a 1 year process of testing and seeing how the system works.

Henk Van Dalen: Exactly. It’s important to mention that the Pacific trials was a first of a series of tests to understand if the system was suitable enough to proceed towards the Garbage Patch. This has proven to be the case, none the less, we still have a lot to learn about the system. First of all, the actual behavior of doing various weather conditions over a year so, we’re also going to enter into the winter season, for example. We also have to understand more about the ability, how the system actually concentrates and retains plastic so we can extract this and bring this to the shore for recycling and the third parameters of the yearlong operation is also to test the survivability in the longer term from all these, while this year long of operations we really want to collect a lot of data and implement this in future systems as lessons learned. So, this is the start of a series of testing, you can say, but we still have quite a while to go.

Yuse Lajiminmuhip: Can you share some of the details on how the performance will be measured? How can The Ocean Cleanup understand that this is potentially working in the way that it was designed to work?

Henk Van Dalen: There’s various ways that we do that, one of the things that we have for example is that we have various equipment and sensors mounted on the system itself. An example of this would be that we’ve also connected strain gauges in the compartments of the HDPE floater. These strain gauges measure strain and torque of the tube itself, this is then read out by information pods we have on top of the system and then this data is either transferred to the ship via satellite to our office. So, this gives a lot of information about the behavior of the stresses in the pipe, actually understanding if they stay within the allowable levels as well. In addition to the equipment we have on the barrier itself, we have a monitory vessel nearby for the first few months of operation. This will include flights from TOC crew members and they will be evaluating topics as I mentioned, looking at the system in various wave conditions and they will be evaluating topics as I mentioned, looking really at the behavior of the system, and various wind and wave conditions and also the ability of the system to maintain and, how do you say, the method to extract the plastic. We will do daily visual inspections because what we have basically alongside the system now is what we the monitoring vessel, this is a larger type of anchor handling tug but onboard this vessel are also smaller auxiliary vessels which allow us to come close to the barrier. So, we have visual inspections we’ll do of the pipe above the surface but we also have handheld ROV equipment that we can look subsea and actually explore the impact and the behavior of the screen below the float.

Yuse Lajiminmuhip: Henk, is there anything else you would like to share about the project for our listeners?

Henk Van Dalen: Well, first of all, I would like to thank you for the opportunity to be on this podcast, of course. Also working with AGRU has been a great pleasure so we’re happy to keep you informed where needed. I would suggest definitely keep following us via our social media channels, because we have a lot of updates on what is happening offshore will be shared there. So, you can see it firsthand.

Yuse Lajiminmuhip: Melissa, how about you? I know this is an exciting time for your department because this project brings more attention to the use of polyethylene in large diameter pipe. How do you think The Ocean Cleanup project will affect the perception of this product category?

Melissa Grace: I think that, for AGRU, is honored to be a part of, it’s definitely something that will ultimately, I think, have a positive benefit for the world. Hopefully for the HDPE community overall, we’re able to also demonstrate the attributes and solutions that HDPE pipe can offer in several applications. Together hopefully we’ll see much success.

Henk Van Dalen: Thank you, Melissa. I look forward to it.
Yuse Lajiminmuhip: Henk, Melissa, thank you both so much for your time. We would like to thank The Ocean Cleanup for participating in this podcast. The Ocean Cleanup is a nonprofit organization developing advanced technologies to rid the world’s ocean of plastic. The Ocean Cleanup’s passive drifting systems are estimated to clean up half of the Great Pacific Garbage Patch in 5 years’ time. To learn more about The Ocean Cleanup visit them on the web at theoceancleanup.com. AGRU is an international manufacturer of award winning, precision engineered geosynthetic solutions. AGRU products are an essential component in many industrial, environmental and civil applications. To learn more about AGRU visit us on the web at agruamerica.com.