Historical Origins Exhibition at the WODCON: Yu the Great

Statue of a bronze Ox, commemorating Yu the Great.
Statue of a bronze Ox, commemorating Yu the Great.

Traveling all the way to the WODCON in Shanghai China1 presented an excellent opportunity to visit this wonderful country. So, after the congress, we travelled to Beijing, to visit the tourist highlights. However, as obsessed with dredging as I am, I can find inspiration for the stories on this website anywhere. Take for example this bronze ox. Quietly staring at the Summer Palace2, it might easily be overlooked by the innocent visitor. But it is very relevant for our dredging community. It is to commemorate the great Yu, who subdued the flood with the first dredging project in the world3.

Exhibit about Yu the Great at the historical origin show at the WODCON 2019.
Exhibit about Yu the Great at the historical origin show at the WODCON 2019.

Next to the interesting presentations and the conventional dredging exhibition, the WODCON organisation arranged a nice little exhibition on historic origins of dredging in China. Of course the first exhibit was about Yu. Intrigued by this little piece of information, I asked around and did some research on the internet to puzzle together, what the sign did not tell.

First of all, there are that many records4. It has been so long ago, there only remains oral tradition to consult. The facts are inconclusive, even claiming it is just a mythical tale. So, we will approach this Mythbuster style. Examine the myth and the facts. Test it. And if it does not provide the expected results, take it to the extreme. Unfortunately, we will not blow things up at this time. Maybe we will do that later on another topic.

Sign at the bronze ox at the Summer Palace, Beijing.
Sign at the bronze ox at the Summer Palace, Beijing.

The story depicted on the information sign is not completely in line with the historical data available. Let’s start with the ‘iron’ part of the ox. According to several sources, the adventures of the Great Yu may have happened 2000BCE. That is in the middle of the Stone Age5, at best early Bronze Age. Also, it was usually not ‘to ward of the floods’. Those were mitigated by a framework of dikes, dams and overflow weirs6. When an ox was mentioned, it is about protecting these civil works. But nowhere can I find a solid explanation about what an ox can do to protect a dike or how this procedure would contain the river in its human designed trajectory.

Water buffalo at the Li River, near Yangshuo.
Water buffalo at the Li River, near Yangshuo.

Even today, one can find bovine creatures standing in the river. And from a distance they might easily be mistaken for a field of boulders. Conversely, a field of boulders might also be mistaken for a herd of oxen…

Boulder field or rudimentary groyne in the Li River, near Yangshuo.
Boulder field (or rudimentary groyne?) in the Li River, near Yangshuo.

So, my hypothesis is: ‘the Great Yu constructed his dikes and protected them with groynes against erosion7. When the uninitiated had to describe what he constructed, they compared those with water buffalo and the oral tradition morphed this into iron oxen.’ This is only my opinion after just a little research and it is up to educated historians with their research to disprove it.

Discussing these civil works and the containment of rivers, made me think of my beloved home country through the famous Dutch poem ‘Memories of Holland’8.

Excellent masterpiece of hydraulic engineering to contain a river and example of modern groynes. (Credit: van den Herik-Sliedrecht).
Excellent masterpiece of hydraulic engineering to contain a river and example of modern groynes9. (Credit: van den Herik-Sliedrecht).

References

  1. WODCON, Damen
  2. Summer Palace, Wikipedia
  3. Great Flood (China), Wikipedia
  4. Yu the Great, Wikipedia
  5. History of China, Prehistory, Wikipedia
  6. Chinese Myth of the Deluge, China Heritage Quarterly
  7. Groyne, Wikipedia
  8. Herinnering aan Holland, David Reid Poetry Translation Prize
  9. Kribverlaging Waal Fase 3, Van den Herik-Sliedrecht

See also

My WODCON 2019 Presentation: Launching Robotic Dredging

Me, presenting my WODCON 2019 contribution.
Me, presenting my WODCON 2019 contribution.

Yesterday, I gave my presentation at the WODCON 2019 in Shanghai1. The WODCON is the triannual world dredging conference, were everybody in the dredging industry meets and exchanges knowledge and ideas. Just as I mentioned in my New Year’s post, I sometimes like to delve into some old archives, get inspiration and hatch new ideas2. So did I for this presentation.

Overview of the ‘Ketelmeer’ (Credit: Google Maps).
Overview of the ‘Ketelmeer’ (Credit: Google Maps).

A seminal dredging project concerning environmental dredging is the ‘Ketelmeer’ clean up dredging project, resulting in the creation of the contaminated sediment storage depot in the artificial island ‘IJsseloog’3. As careful removal of the contaminated sediment required novel dredging techniques, the government challenged the dredging industry to test four innovative concepts. The results were evaluated by the institute now called ‘Deltares’ and published in a report4. The original conclusion of the report was, that the auger dredge was the best in reducing the turbidity. Later, the bigger auger dredge ‘HAM291’ was constructed and used to actually clean up the lake. With the knowledge and the experience of the auger we also developed a range of auger attachments for our DOP pumps5.

Traditional auger attachment for a DOP pump excavator combination.
Traditional auger attachment for a DOP pump excavator combination.

Reading the Ketelmeer report again, it occurred to me, that one parameter had not been properly accounted for: the size of the dredge. The auger dredge was by far the smallest dredge in the game. With a weighed scoring method, the dredges were also compared in size and installed power. The reasoning is that a bigger dredge has more interaction with its environment. Naturally, the environment gets more disturbed and turbidity levels should be higher for a bigger dredge. And the data was there to support this hypothesis. Smaller is better! Still, this does not undermine the initial results of the concept, as that was evaluated for turbidity per cubic meter. The bigger dredges also delivered more production. But when comparing dredges of the same concept might the smaller ones will perform better on turbidity. And this is in accordance with our experience. Every project where we’ve supplied these auger dredge units, the contractor and the client where surprised and happy about the achieved turbidity levels. Now, we know why: smaller is less turbidity.

The next step in performance might be reached by further decreasing the size of the dredge. However, the DOP is already as small as it is for a viable application on an excavator. The conclusion is to have an auger operating directly on the bottom: an unmanned submarine dredging machine!

Possible general arrangement of a robotic dredge submarine.
Possible general arrangement of a robotic dredge submarine.

This machine should navigate by itself and self-supporting. The wear parts of the auger should be exchanged by itself and solar panels can provide extra energy for extended missions. It has only a small hopper and discharge should also be done quick and automatically. An unmanned barge or even a dump truck trailer at the shore of the waterway can be replaced at longer intervals. Obstacles and other tricky spots can be alerted to a human supervisor for later intervention. One machine alone does not have an impressive production. The real power is in applying them in numbers. As we are standing on the brink of a revolution in robotics and artificial intelligence, this scenario may be not as farfetched as from your first impression. Imagine a whole school of these mechanical fishes cleaning up your waterway, while you sleep…

Working method of robotic dredge submarine (Credit: Judith Korver).
Working method of robotic dredge submarine (Credit: Judith Korver).

References

  1. WODCON, Damen
  2. New Year’s post 2019, Discover Dredging
  3. Ketelmeer project, Wikipedia
  4. Rapportage baggerproeven Ketelmeer. RIZA Rapport, 97.023, ISBN 9036950708
  5. DOP Pumps, Damen

See also

Novel Density Measurement By A Little Dredging Engineer

 

Design of an experiment to test a novel density measurement.
Design of an experiment to test a novel density measurement.

Innovative ideas need an open mind, not hindered by trodden paths of thought that limit one’s ability to be creative. And whose mind is open and flexible enough to trust such a task? Children! In order to keep me sharp, I sometimes discuss tricky problems at the dinner table with my daughter. Lately I presented her with the problem of density measurement in a slurry pipeline. There is a well-known technology: nuclear radiation dissipation detection. But there are already two words in that concept that we are asked to replace with a safer and more environmentally friendly alternative1. Her solution was to measure how much particles would stick on a glue lathered rod held in the mixture flow. During one of my daughter’s holidays from school, we took the opportunity to test her novel concept.

Preparations for the density measurement experiment.
Preparations for the density measurement experiment.

If this is going to be a novel measuring technique, we should prove, that there is a relation between the amount of particles sticking to the glue and the density of the mixture. This had to be tested in a controlled experimental environment: a bucket. We filled it with a known amount of water and by adding sand to it, we gradually increased the density. There were several types of glue to be tested, which we applied to short pieces of PVC tube. Glues we considered were: hobby glue, mounting kit, wall paper glue, contact adhesive and duct tape. There was one reference tube with no glue. We kept the samples in the mixture for 30 seconds, while vigorously stirring the slurry with a mixing drill.

Density measurement in progress.
Density measurement in progress.

Before and after the sample was dipped in the slurry, we measured the mass of the sample on a scale. The difference in mass should represent the amount of particles that stuck to the glue. These differences were recorded and plotted in a graph. Surprise! There is a distinctive trend in the data points that would support our hypothesis on the relation between mixture density and particle capture.

Results of the density measurement.
Results of the density measurement.

Some remarks on these results. There is a wide variation in trend lines. Some of the samples became lighter than they started. Probably, because they dissolved in the mixture. The measurements for the 600 and 1200 grams of diluted sand is notable. This is probably related to an observer variability. The strongest relation between mixture density and grain capture is with contact adhesive and duct tape. Interestingly, the best predictor for the average capture over the glue types was the reference tube. Probably, the water clinging to the tube already contained enough particles to result in a measurable signal.

It was fun to do this exercise and the results are interesting. But, I doubt we can make a viable product out of this concept. In the dredging industry, we prefer a non-invasive technology, the sample rod would be knocked out in seconds. Several manufacturers are already developing alternatives2,3. In our ¡VAMOS! project, we tested one concept, that seems very promising and you will definitely hear more about it in due time. It is time to say good bye to the nuclear density sensor and adopt technologies that are future proof. Our children will be grateful if we leave them a better world.

Non-radioactive density measurement (Credit: ¡VAMOS!).
Non-radioactive density measurement (Credit: ¡VAMOS!).

References

  1. Regeling bekendmaking rechtvaardiging gebruik van ioniserende straling, Staatcourant NL
  2. Magnetic resonance multiphase flowmeters, Krohne
  3. ITS exhibiting at Europort and CEDA Dredging Days 2017, ITS

See also

Production management, Damen

Discussion at LinkedIn post