2021: Muddling Along To A Healthy Year In Dredging

Calendar picture of a sunny dredging site
Calendar picture of a sunny dredging site

Dear readers, I sincerely wish you all the best for this new year. As things are looking positive on the vaccine front, we should keep testing negative this year. There are lots of items and events to look forward. Last year was not quite what we’ve hoped for and wished each other.

I do hope all of you are OK and are still together with your loved ones. I am fortunately in that respect. So, next to the Covid situation, there were a lot of other noteworthy items. Most of them have been featured here on Discover Dredging. My trip to Bangladesh, just before all the lockdown measures. The graduation of Carsten1 and Omar2 that were completely over Teams. Some attention to our Damen Dredging Experience3. And some other items. Did you enjoy the Donald Duck review?4

Opening scene of ‘Muddy Fine Business’ or ‘Success Test’ (Credit: Disney)
Opening scene of ‘Muddy Fine Business’ or ‘Success Test’ (Credit: Disney)

One sad event was, the last issue of Dredging and Port Construction5. We’ve had to say goodbye to our trusted DPC. Although by now, there has been a kind of digital revival on the CEDA Website6. They opened up a section for Industry News, edited by Namrata Nadkarni. It stands out from the other online media covering dredging as there has been some attention to smaller topics, that would normally not get covered. As I think it is a good initiative, I urge you to subscribe and also participate by sending them any noteworthy news items for publication. Not specifically the usual company press releases, but also the more thought provocative opinions and perspectives on the activities of our dredging community. Active participation could make this CEDA Industry News flourish this year.

Announcement of the CEDA Industry News section (Credit:CEDA)
Announcement of the CEDA Industry News section (Credit:CEDA)

Further personal activities within CEDA are the Dredging Management Commission7 and I am looking forward to the exciting new concept for the CEDA Dredging Days8. Will you participate? Also, I already took the course on ‘Dredging for Sustainable Infrastructure’9, but you should keep an eye out on the next instalment, coming soon10.

A continuation from last year on my Discover Dredging will be some more articles on our Damen Dredging Experience. There are still some exhibit left to review and teaser:… There are some new exhibits arriving! Hope to have that covered when the pandemic will fizzle out we can show you around through our museum. And I hope to continue on pump and dredge technology.

Overview of the Damen Dredging Experience
Overview of the Damen Dredging Experience

Currently, there are some students working on their graduation thesis. Their very interesting topics will be highlighted here as well. Some others will start soon. When you are looking for a fun place to have your internship our your graduation, you might consider a visit to our career page11 or contacting Frank Bosman for any opportunities. Although most positions are filled at the moment, later this year we would welcome fresh brains again.

As our offices will be closed for regular work, I will be working from home most of the time. Probably most of you will do likewise. To keep track of the passage of time over the days, you should have a calendar. As a special service to my audience, I was granted the use of a set of beautiful pictures to create a calendar. You can download the file here and with some DIY skills you should have some original wall decoration for this year.

Stay healthy and stay safe. Hope to see you later this year.

Selection of calendar pictures
Selection of calendar pictures

References

  1. Graduation Of Carsten Markus: Designing And Casting Of Impellers, Discover Dredging
  2. Graduation Omar Karam: Rock Cutting The Egyptian Way, Discover Dredging
  3. Selected articles on the Damen Dredging Experience, Discover Dredging
  4. Book Review: Donald Duck A Muddy Fine Business; Artistic Equipment Design; Discover Dredging
  5. The Last Dredging And Port Construction Magazine, The End Of An Era; Discover Dredging
  6. Debut of CEDA Industry News section and monthly newsletter, CEDA
  7. Selected articles on the CEDA Dredging Management Commission, Discover Dredging
  8. Call for Papers for CEDA Dredging Days 2021 issued, CEDA
  9. Book Review: Dredging For Sustainable Infrastructure, Discover Dredging
  10. 2nd Online Course Dredging for Sustainable Infrastructure planned for March 2021!, IADC
  11. Welcome to the best years of your life, Damen

See also

Book Review: Dredging For Sustainable Infrastructure

‘Dredging for Sustainable Infrastructure’ (Credit: CEDA & IADC)
‘Dredging for Sustainable Infrastructure’ (Credit: CEDA & IADC)

Last week, I attended the last sessions of the ‘Dredging for Sustainable Infrastructure’ course, jointly organised by CEDA1 and IADC2. This course is intended to quickly absorb the contents of the book of the same name3 and have a hands on experience of the novel methodology proposed. The book has been written by many different people as members of the participating organisations. As such, it is the condensed knowledge and ideas of the dredging community on a modern approach to infrastructure projects. Although there is a straightforward structure in the book, the publishers initiated courses as an introduction to the book.

Structure of the book (Credit: CEDA & IADC)
Structure of the book (Credit: CEDA & IADC)

As Covid-19 swept across Europe and thwarted the intended live course days, the sessions were postponed and eventually held online. The presenters, Erik van Eekelen, Thomas Vijverberg and Mark Lee did a good job of introducing us to the book and supervise us in the break out working groups. The central storyline of the working groups was the harbour expansion of the fictional port of Tomigo in the fairy land of Quandany. Each of the participants was assigned a role to represent the consultant, the fishing community, the nature conservancy organisations, the power plant etc. A revelation for me from this interaction is how easy you are inclined to be egocentric in the defence of your interests. With just a little more attention to the other interests, there might be much better opportunities for yourself and for the whole of the project.

New harbour basin development at the port of Tomigo (Credit: CEDA & IADC)
New harbour basin development at the port of Tomigo (Credit: CEDA & IADC)

The incentive to produce a book on this novel approach in dredging projects was the UN initiative to launch 17 Sustainable Development Goals4 and the book addresses most of these goals. If we can truly lift the proposed working procedures into an industry standard or even a social mentality, this will be a paradigm shift from where the project was the centre of attention to: ‘Where can nature and society benefit from an economic requirement?’ The next step will be from philosophy to action.

United Nations ‘Sustainable Development Goals (Credit: United Nations)
United Nations ‘Sustainable Development Goals (Credit: United Nations)

The focus of the book is very much on the initial stages of a project: include sustainability on the basis of the design of a project, demonstrating options for sustainable solutions suggestion of sustainable techniques. As a dredging equipment manufacturer5, most of the topics will not affect my daily work. Still, in the work group sessions, it was interesting to see the interaction between the various parties that are involved with the initiation of a project. As a dredge builder4, we usually meet the requirements for the equipment applied. Though, the technical solution to achieve this might be not the most commercial solution. However, the book makes it clear and provides examples, that taking all aspects of a project into account, including social and nature opportunities, the benefits of a sustainable approach of a project might still make a viable business case.

Three pillars of sustainability (Credit: CEDA & IADC)
Three pillars of sustainability (Credit: CEDA & IADC)

The verdict on the book: it is a reference book. And as such it is very tiresome to plough through. However, the course is very enlightening as introductory lectures into the contents. Then the meticulously compiled information starts to live. Don’t depend on the courses alone, also leaf through and note all the valuable tables, graphs and diagrams, especially the guiding boxes that can assist you in setting up your dredging project. It definitely belongs on your bookshelf.

‘Dredging for Sustainable Infrastructure’ in our bookshelf
‘Dredging for Sustainable Infrastructure’ in our bookshelf

References

  1. CEDA and IADC launches new ‘Dredging for Sustainable Infrastructure’ Course, CEDA
  2. Online Course ‘Dredging for Sustainable Infrastructure’, IADC
  3. Dredging for Sustainable Infrastructure, CEDA&IADC
  4. The 17 goals, United Nations
  5. Damen Dredging Equipment, Damen

See also

Sensible Flow Sensing Stories, The Correct Capacity Measurement

Example of a flow meter on a Cutter Suction Dredge
Example of a flow meter on a Cutter Suction Dredge

My last posting was a nice story about how they measured mixture velocity in the old days1. Luckily, we have a much better solution nowadays: the electromagnetic flux flow meter2. It is real time and can be viewed from the convenience of the operating cabin. This device can be part of the production measurement for a CSD, TSHD or sometimes in a separate production measurement unit.

Combined velocity and density indicator in the operating cabin
Combined velocity and density indicator in the operating cabin

The working principle of an electromagnetic flux flow meter is based on the Faraday laws of induction3. When a conductor moves through a magnetic field, a current will flow in the third direction perpendicular to both. Due to the resistance of the water, the resulting potential can be picked up by electrodes that are in contact with the mixture.

Explanation of the electromagnetic flux flow meter
Explanation of the electromagnetic flux flow meter

For the principle to work, the electrodes and the mixture have to be isolated from the housing. This is why you always have some isolating liner in this type of flow meters. Off course, the isolation material will wear down due to the abrasion of the mixture. Usually when working in relatively soft sediments, the isolation liner is made of durable polyurethane rubber. The electrodes are flush with the surface of the liner and are not much exposed to wear. When the liner is worn down, it can be easily replaced by the supplier. When working in a more abrasive environment, a more durable isolation liner can be chosen. e.g. Ceramic tiles embedded in a soft adhesive layer.

Arrangement of an electromagnetic flux flow meter
Arrangement of an electromagnetic flux flow meter

The measured voltage gets processed by an amplifier that has to be placed close by. The outgoing signal is mostly the usual 4-20mA and can be transmitted directly to a velocity indicator or a production indicator. Sure, it is good to have a high velocity, as that represents a good production. But it is also indicating a high power consumption. One is more sensible to increase the mixture density and decrease the velocity for an efficient production. To monitor the dredge process, both signals can be combined in a single indicator to present the production to the operator.

Example of different executions of production indicators
Example of different executions of production indicators

The left example is the classic ‘mechanical’ cross-needle indicator. Where the needles intersect, the production can be read on the lines between the scales. On the right, the rotating needles have been replaced by digital linear scales. The velocity is represented horizontally and the density vertically. Consequently, the production lines are also modified. Instead of a high production vertically in the centre, the highest production is now in the upper right corner.

These flow sensors are quite accurate and are reliably indicating the correct value. Still, it is good practice to check the indicated flows, after installation. This calibration can be done for one or two points. The easiest check point is with static water. The other point will be with some known flow. If the installation is on a TSHD, it is straightforward to fill the hopper. Be aware, that the flow has to be integrated over the filling time. For a CSD type application we may have to resort to the described end of pipe indicator from previous post. And if the values are off, erratic or otherwise not making sense, you might have to check whether the housing of the sensor is correctly grounded to both other flanges.

Ungrounded and correctly grounded housing of a flow sensor
Ungrounded and correctly grounded housing of a flow sensor

References

  1. Increase Your Dredging Knowledge At The End Of The Discharge Line, Discover Dredging
  2. Magnetic flow meter, Wikipedia
  3. Faraday’s law of induction, Wikipedia

See also