DMC – Discover Dredging

CEDA Dredging Days 2021: Sustainable Dredging And Innovation

Promotional banner of the CEDA Dredging Days 2021 (Credit: CEDA)

Tomorrow, another event with a long tradition will start: the CEDA Dredging Days1. Due to the Covid issues, this time, it will be a virtual event, just as a lot of other regular happenings. Hopefully, it will be the last days of this dreadful period. I can’t wait to meet people again in real life. Back at the office, we are slowly starting to get back. But meetings with people far outside the regular circle were difficult. For instance, I was a member of the Technical Paper & Program Committee and the preparation was completely digital.

Home page of your CEDA Dredging Days on the Swapcard platform (Credit: CEDA)

Now, the event itself is also digital. Of course, this is still not the real thing. Having a coffee and a chat in the lobby is a much more enjoyable experience than sitting in front of your screen. I have to say that with the Sawpcard platform2 selected by the organising committee, it is much easier to arrange your own program, adapted to your personal interests. Moreover, it will also facilitate meeting people with the same interest. In a sense, this might be an opportunity to approach those. In the real world, people will not get seated next to you when they have the same interest. And certainly don’t have them captioned on their chest.

Pump design workflow (inspired by Suman Sapkota)

As member of the TPPC, I had the opportunity of a sneak preview of the articles and presentations and I can guarantee there are a lot of interesting sessions. For starters, there are three presentations by my colleagues. Suman Sapkota will have presentation on his research in various novel methods to apply numerical research into the design of dredge pumps3. We are happy to share with you some experiences and insights on the Dredging Days.

Testing the non-radioactive density sensor

Another presentation will be by Frank Bosman4. He has been active in the development of an instrument that will measure the mixture density, without using a radio-active source. This intelligent solution is not only more sustainable, but will also provide easier access to this information. If you don’t know the density, you are very likely to underperform with your dredge. He will present some experiences and data gathered on the performance of this system.

Example of recent electric DOP dredge family

Our last presentation will be by René Sens3. Less technical, but surely an interesting perspective on the future of dredging equipment. Everyone in the dredging community is aware of the necessity to change and adapt to a more sustainable approach of our dredging business. There is an urgency to reach the goals set by the UN to leave the world behind as a better place than we received it. Although usually an increase in size also increases the efficiency of a dredge, the UN goals look beyond that single parameter. With that in mind, small and medium size dredges will be far more interesting than at first sight.

Session 7: Young CEDA ask a CEO (Credit: CEDA)

There will be a lot more going on and I could produce a long list of other interesting presentations. I think you should also check out: Edwin de Hoog and Joep Goeree, Basel Yousef and Jeroen van Stappen, and if you really want to get academic: Janek Gundlach, Ebi Shahmirzadi and Arno Talmon. You can just add to your own list and see who also joins in in the audience. Other interesting sessions will be the student ‘Flash Talks’5 and the ‘Young CEDA ask a CEO’ session6 with Peter Berdovski and Kees van de Graaf. And I am very curious what the other working groups and commissions of CEDA have to present about their work.

Thursday evening is the big get together of the dredging community; meet you there! (Credit: CEDA) — Dredging Days as a they used to be: personal interaction (Credit: CEDA)

References

CEDA DMC Works On A Guidance Paper For Soil Investigation

CEDA Dredging Management Commission WG on Soil Investigation (Credit: CEDA)

Did you ever start a project and it turned out that the conditions were different than expected? Welcome to the dredging industry. One of the most underestimated preparations for a dredging project is the soil investigation. As this investigation is of the utmost importance for the dredging community, the DMC is preparing a guidance paper on this topic1, which we discussed last meeting (February 7, 2020, IMDC, Antwerp).

Working for a dredging equipment manufacturer, I am not much involved in the actual soil investigation. However, often our clients base their purchase of a specific type of equipment on the soil investigation and as such we are often presented with the reports on soil investigation. Based on these reports, we calculate the possible production for various types and advise the client for a dredge that will meet their requirements on the maximum production. most of the time we provide a good advise and the client is happy.

Off course there have been occasions where the performance was not as expected. Often because the report on the soil investigation was inadequate. Either the report did not contain all the details, or the investigation itself was lousy. Either way, rubbish in, is rubbish out. Just as an example, let me tell you what can go wrong, when the information is not representing the real circumstances.

One of our products are the so called ‘DOP Dredges’2. They are based around the versatile DOP pump. Basically, it a DOP suspended on an A-frame on a pontoon with a powerpack. The DOP can be lowered into the sediment and create a typical suction dredge pit. The production is more based on the rate that water can enter the bank face and the velocity that the banks recede. Our client provided us a Particle Distribution Diagram of the available sediment3. It was a nice narrow graded sand, but there was a considerable fines tail on the lower end. This was being dealt by the washing and screening installation. According to the client was this the sand characteristic from the whole pit. And what could be better? If you excavate all the material, you really know what is there, right?

Difference between expected soil conditions (left) and real situation (right)

Well no. As it happened, there were cohesive silt layers between the narrow graded sand layers. When dredging, they sucked at the bottom of the pit. Any silt layers gradually broke of and disintegrated by the eroding density flow. As the pit was created over a long period, the falling chunks of silt just slid down the slope, without causing any harm.

Enter: the new DOP dredge. It started in a new corner of the pit and initially had some trouble penetrating the silt layer. Eventually it managed to get through and started excavating a cavity below the silt layer. These broke of, burying the DOP. Without any possibility to recover the DOP, it turned into a very expensive anchor.

Risk of getting your DOP trapped in a cavity under the cohesive silt layers and the solution

If the presence of these cohesive silt layers would have been known, we would have adapted the suction pipe for a deeper penetration. That prevents the DOP becoming covered and facilitates easier extraction. This story proves two things: 1. A proper soil investigation can prevent costly accidents and budget runovers. 2. A DOP can be modified to most requirements, when the circumstances are known.

Meanwhile, the DMC is preparing its guidance document to assist you in preventing problems like this. Follow CEDA for updates4.

Standard suction tube (left) and long suction tube (right)

References

The Real Benefit Of Becoming An Individual Member Of CEDA

Young CEDA pitch talks at the CEDA Dredging Days 2017 (Credit: CEDA)

Do you remember the beginning of my website two years ago? The first public posts on this website were about the CEDA Dredging Days 20171. It has been a long time since then. Back then, I couldn’t have guessed what direction this website would take. By now, this is my sixtieth post! Some memorable moment in itself. Still, I would like to do what I intended to do: share knowledge about dredging. And a preview on the next CEDA Dredging Days in Rotterdam2 is a fitting commemoration of all the other posts in between.

Off course, the renowned CEDA Dredging Days are a platform to meet people and exchange knowledge. Especially all the presentations. That everybody has been sweating on writing the manuscript. Reviewed by the scrutiny of the Technical Paper and Program committee3. From personal experience, I can tell you, there are a lot of interesting papers. You’ve had already a teaser on the presentation of Camille Kapela4, about the dredging project in Monaco5.

Camille Kapela at the CEDA Dredging Days 2017 (Credit: CEDA)

Another I would recommend is the presentation of my colleague Frank de Hoogh about the new MAD gravel hopper dredge6. It is not just another boat, it is a change of concept. And there are so many interesting innovations on this dredge, that it merits its own sneak preview.

Innovative Marine Aggregate Dredge for gravel dredging

But there are more interesting perspectives on the event. In contrast to other commercial conferences on dredging, this is like a gathering of a community. It is a place for all the commissions and working groups within CEDA to present their efforts and show the reports and results of their work. There is a presentation of the Working Group on contract selection7, an update from of the Working Group on soil investigation and an interactive session themed on the recently published book: ‘Dredging for Sustainable Infrastructure’8.

The interactive session at the previous CEDA Dredging Days (Credit: CEDA)

Above all, it is a social event. All the knowledge presented would be worthless, when there is no community that absorbs the produced information. Would discuss about the content, the feasibility and possible applications. And these discussions generate innovative ideas on the new insights from the presentations and meetings.

Sometimes, I am asked: ‘What good is it to be a CEDA member myself? I can get the benefits of the presentations, the reduced price and the drinks, through the membership of my company. Why would I throw out my personal money?’ Well, it is not about all that. It really is about people and building a community. Having a (small) personal investment brings you in the state of mind, that you belong to this wonderful community with its long history in shaping the world. And that is the real benefit of being an individual CEDA member9. With this personal contribution you can take part of shaping the future of the world.

Tag: DMC

CEDA Dredging Days 2021: Sustainable Dredging And Innovation

References

See also

CEDA DMC Works On A Guidance Paper For Soil Investigation

References

See also

The Real Benefit Of Becoming An Individual Member Of CEDA

References

See also