Happy 2019!

Post card picture of a Damen CSD500 at work.

Happy New Year! First of all, I would like to wish you: health, happiness and a year full of dredging action. And there will certainly be some dredging action. We will start this year with closing our ¡VAMOS! project and we will close off with another CEDA Dredging Days1, just as with which this blog started one year ago with a new year’s resolution.

Further topics will include the upcoming WODCON conference in Shanghai2, more CEDA Dredging Management Commission, some interesting book reviews and whatever happens along the way. Maybe I can get back on working on articles that explain interesting phenomena in dredging technology. Or just some funny experiences I had in our beautiful profession. There are so many memorable moments worth sharing for the general benefit.

And George Santayana has warned us to learn from the past: ‘Those who cannot remember the past are condemned to repeat it.’3 I don’t fancy that this site will be a monumental source of reference for posterity. There are much better institutes to store and share dredging knowledge. e.g. the CEDA comes to mind. It’s ‘a forum for all stakeholders involved in the dredging industry’4 and there are many working groups were the current knowledge is shared and stored in publications.

A much better place to look at a condensation of knowledge over a longer time span is the National Dredging Museum5. You might have noticed, that I am very fond of museums. I like to dwell through their expositions, relive the past and see the origins of current technologies. When I am trying to hatch some new sort of gizmo or gadget to perform a very peculiar dredging requirement, I can relate to all those branches of the technology tree, that are out there and see if there is something that can be combined in a new contraption.

Model of a ‘Krabbelaar’ or ‘Scratcher’ at the National Dredging Museum.

Sometimes you can recognize some technology in an exhibit, that was ahead of its time. Take this ‘Krabbelaar’ or ‘Scratcher’. It loosens the top layer of the sediment and expected it to flush out at the outgoing tide. Considering the enormous forces for cutting and internal friction, that have to be delivered by sail power, I doubt the production would make a viable business case. Nowadays, you would employ a dredge plough behind a tug6. Modern propulsion delivers the thrust needed for all requirements. Ploughing, scraping and smoothing has become much easier and modern hydrological simulations will give a better idea about the possible production and where the sediment will end up.

Example of a modern dredge plough, fitted on a Damen Stan Tug 1606.

Possibly our modern dredge plough technology will be surpassed by even better concepts. Maybe, regulations or fuel economy would direct us back again to a sustainable form of dredging management and the old scratcher makes a comeback in a modern form. And then, you know to find the origins in the National Dredging Museum.

I think, it is very important, we cherish our dredging heritage. For ourselves and for our posterity. Just as we support our trade associations, we should support the dredging museum. So, now I come back to my ‘new’ new year’s resolution: I will become patron7 to the National Dredging Museum. It is not much, but if it inspires you to do the same, we can make a difference together.

Collection of dredges.

References

  1. CEDA Dredging Days 2019, CEDA
  2. WODCON XXII, CEDA
  3. George Santayana, Wikipedia
  4. Our mission and strategy, CEDA
  5. National Dredging Museum
  6. Scrabster Harbour takes delivery of Damen Stan Tug 1606, Damen
  7. Sponsoring 2018, National Dredging Museum

See also

Ploughs, Beams and Rakes, IADC

 

 

 

Book Review: En De Sé Wie Net Maer

Book cover ‘En De Se Wie Net Maer’ by A.A. van der Werf1.

Another holiday is coming up. Another book recommendation for the armchair dredger. Well, Christmas, New Year’s Eve, a lot of preparations in just too short a time. Probably too little time to read a book. That fits, today’s book under review is only partly interesting from a dredging perspective. It is about the reclamation of the Noordoostpolder. Moreover, it is written in Frisian. So, also only a selected part of the audience will be able to actually read it. Then, why recommend it anyway? Because it will give you a good anecdote at the dinner table, where you can proudly illustrate the ingenuity of us in the dredging industry.

Historic map2 of the Noordoostpolder from 1946. (Credit: Emmeloord.info)

First some introductory details about the Noordoostpolder3. A polder is reclaimed land by isolating it from the sea by a dike and pumping the water out4. It provides cheap land with relative little soil movement, only the dike. In the early twentieth century, the Netherlands needed lots of land for a rapidly expanding population, agriculture and industry. The first real big polder  was the ‘Wieringermeerpolder’. And the ‘Noordoostpolder’ was the first real IJsselmeer polder, as it was started in 1936 after the closing of the ‘Afsluitdijk’. Work continued well into the second world war. And part of the book is about the interaction of the German army, the Dutch people and the resistance. Due to this storyline, the book is also, part fact, part fiction.

Canal dredging in the still submerged Noordoostpolder.

One fact in the book was right. In the polder, you would need canals for drainage, irrigation and transportation. And the easiest way is to dredge it. Although not a real historic account of the events, the book does contain pictures of the project. And in the picture above, you can see something special: a bucket ladder dredge with a pipe line! Normally a bucket ladder dredge5 would load barges, but the very shallow lake and the narrow canals were not facilitating easy handling of the barges. In these cases, they used some sort of soil pump. In the above picture it cannot be seen, but in the archives of my work, we have lots of pictures of them. Basically they are big boxes with jet nozzles and dredge pumps connected to a discharge line. The end of the discharge line could be positioned over the location of future roads and effectively deposit the foundation of the road.

Soil pump ‘GP3’ by De Groot Nijkerk, at work in a narrow canal, here loaded by drag lines.

Nowadays, you would probably use a barge and suspend a DOP in it6.

Unfortunately, the second world war intervened. Still, the German occupation brought the project to a conclusion. The story details about the contractor (‘Verhei’*) not willing to cooperate with the occupier after the project. So, he had his dredge (‘Holland’*) enclosed within the dike. There were locks in the dike, but the pontoon was too wide for the locks. This prevented the confiscation of the dredge. After the liberation, the dredge was still there, and everybody was laughing at the contractor, as his dredge was hemmed in the dike. It turned out , he outsmarted them all. He removed everything above the deck line and with two floating gantries he coaxed the pontoon through the locks on its side!

Pontoon of bucket ladder dredge ‘Holland’* on edge for lock passage.

*Names are fictionalised by the author, but he states that the described events did really occur as described.

References

  1. En De Se Wie Net Maer, A.A. van der Werf
  2. Urkerland of Noordoostpolder, Emmeloord.info
  3. Polder, Wikipedia
  4. Noordoostpolder, Wikipedia
  5. Emmerbaggermolen, Wikipedia (Dutch)
  6. DOP Pump 350 with leveler head, Damen

See also

Exhibition ‘Sand On The Move’ At The National Dredging Museum

Flyer for the exhibition ‘Sand on the move’ (Credit: National Dredging Museum).

As we’ve seen in my last post, sand is one of the commodities most in demand1. Here in the Netherlands, there is a whole industry built on the extraction and distribution of sand. One of the most used extraction methods is dredging, something we’re well acquainted with. One of the most used distribution methods is barge transport. And the National Dredging Museum has opened an exhibition on these complementary trades: ‘Sand on the Move’2.
Last Thursday was the opening of this new exhibition of the museum. For the occasion, there were two speakers invited. Kees van der Veeken, director Consortium Grensmaas showed us the current practice of sand mining. Tjeerd Roozendaal, head engineer – program director projects and maintenance of Rijkswaterstaat had the honour to open the exhibition. Afterwards, there was a dinner buffet available for the guests. An excellent opportunity to learn, hear opinions and build on your (dredging) network.

Panoramic view of the ‘Sand on the move’ exhibition.

Our modern infrastructure was only made possible by the application use of sand as foundation of roads and fill material in concrete and tarmac. At the exhibition, there are displays of four big projects about sand mining: ‘Betuweroute’3, ‘Kraaijnbergse Plassen’4, ‘IJsseloog’5 and ‘Grensmaas’6. Each highlighting a certain aspect of sand mining in the Netherlands.
Another part of the exhibition revolves around the distribution of sand. And this posed a chicken and egg problem: in order to build roads, you need roads to transport the sand. So, in the early days, before there were roads, sand was being delivered over water by barge. There was a short period, where numerous small enterprises, mostly family owned, filled the gap of transporting sand by barge, taking the place of delivery trucks. Also my family had a motor vessel for sand transportation, ‘Excelsior’. And my grandfather told me many times of his adventures on board and his relative happy times. As this was hard work for sure.

Motor sand barge ‘Excelsior’ (Credit: Co Winkelman).

Along with old photographs of those sand barges, there are also many models and a video exhibit. Each conveying respect to these men, women and sometimes children, that have been toiling to build the roads and railways that we are now taking for granted in our luxurious times.
Unfortunately, these businesses worked to their own demise. As roads and railways improved, there was less need to transport the sand by barge, but directly hauled to the location where it was needed by road. So, somewhere this typical business dried up. Nowadays, sand is still transported by barges, but they are usually owned by large companies, that own the whole product line from extraction, distribution to application.
There is also a small sand laboratory to experience yourself, how many different aspects of sand are involved in selecting the right sand for the right application. At a small scale and easy to understand steps, this represents how we are evaluating sand in our own laboratory. Next to this laboratory, there are many more kid friendly exhibits in the rest of the museum. I can highly recommend you to plan a visit to the national dredging museum these weekends or during the Christmas holiday.

Mini sand laboratory (Credit: National Dredging museum).

References

  1. The World in a Grain, Amazon
  2. Sand on the Move, National Dredging Museum
  3. Betuweroute, Wikipedia
  4. Kraaijenbergse Plassen, Wikipedia (NL)
  5. IJsseloog, Wikipedia
  6. Grensmaas, Wikipedia (NL)

See also