Troubleshooting
During the tender phase an estimation of the production is required for the dredgers that will do the job. The estimate is based on soil data that comes with the tender documents, the specs of the dredgers and the knowledge of the production estimator.
During the execution of the job, the actual achieved production rates will rarely match the estimated values. In case they are lower than expected, this can become very problematic and solutions need to be found on board to minimize the gap.
A lower production rate than expected, originates in one or more different aspects of a dredging job:
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excavation rate
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pumping ashore production
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dumping rate
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overall production rate
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wrong or insufficient soil data
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excessive wear and tear
Each of these problem sources needs to be solved in a different way but in general it will be based on a combination of theoretical background and experience on board. This is one of the missions of Innovate2Dredge.
![P20-01-12_13.12[01].JPG](https://static.wixstatic.com/media/86d01c_94d661b3a47e449ba714cb2ef85d84f8~mv2.jpg/v1/fill/w_491,h_368,al_c,q_80,usm_0.66_1.00_0.01,enc_avif,quality_auto/86d01c_94d661b3a47e449ba714cb2ef85d84f8~mv2.jpg)
Excavation rate
The most common reason for low production rates is the excavation rate. Based on the soil data, an excavation production is expected for a specific dredger. But during the execution of the job, the actual production can be lower than expected. In most of the cases, this will be in soils that are very unpredictable - and therefore difficult to quantify during tender phase:
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dense to very dense soil types such as glacial till and dense fine sand
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cohesive hard soils
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soils containing boulders or boulder sized obstructions
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different soil types interacting in a negative way
What can we do for you in this case?
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if datalog files are available: make a quick office-based assessment of the problem and possibilities to tackle it
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go on board to get a better view on the problem and try to solve it by implementing structural changes on the dredging head, mostly small and quick changes on board or local workshops
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look for production improvement through adapted way of dredging
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if the problem is recurrent for the dredger or company, design a custombuilt head for higher efficiency of the dredger on future similar jobs
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write a report about the problem and solutions that can be used for continuous improvement
Pumping ashore production
Pumping ashore productions that are lower than expected can be the result of difficult behavior of certain soil types (such as gravel) or technical problems of the dredger.
What can we do for you in this case?
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if datalog files are available: make a quick office-based assessment of the situation and possible improvements
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adapt the pumping methodology after a theoretical analysis of the pumping characteristics and soil specifications
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structural changes on the discharge line
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write a report about the problem and results of the implementations on board
Overall production rate
Even if the separate elements of the production rate are maximized, the overall production rate can still be lifted as we always need to look at the big picture of a job. Many combinations can be found but the most common are:
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even if the excavation production stays the same, extending the loading time can gradually raise the production in dense sand
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under other circumstances, extended loading times can create problems in clayey soils
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overdepth dredging can be beneficial on one job and problematic on another
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some soil types can not be dredged together but separately, or in a different order
What can we do for you in this case?
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if datalog files are available: make a quick office-based assessment of the situation and possible improvements
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go on board and look for the highest overall production rate by taking all the elements of the job into consideration: jobs specs, survey data, local circumstances and ships state and specs
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write a report about the initial situation and results of implementations on site
Wrong or insufficient soil data
Sometimes, the soil data will be erroneous or insufficient, resulting in a wrong soil model. In this case, the actual production will certainly not match the estimate.
In such a case, it is necessary to go on site as soon as possible to get an idea about the actual type of soil dredged. This is very important as this will be used for adapting the way of dredging and can be the basis of a claim settlement.
What can we do for you in this case?
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go on board to get a correct view of the soil types dredged
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adapt the soil model based on the experience on board
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use this adapted soil model as a basis for adaptation of the way of dredging and make a new estimate of the production rates
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make a proposition for additional soil investigation to correct the existing model
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give advice for sampling and data collection to prepare a claim settlement
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write a report
Excessive wear and tear
In some soil types, wear and tear can be very high and result in a high cost of consumables or idle time for repairs. The direct and indirect costs can become very high, but there are solutions to this type of problem. Distinction needs to be made between expected and unexpected wear and tear.
What can we do for you in this case?
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in case of unexpected wear and tear: offer advice for quick changes on the dredging equipment to cope with this problem. This can be advice on use and mounting of wearing parts or structural changes on the dredging equipment
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in case of expected wear and tear:
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give advice on wearing parts
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design wearing elements for dredging equipment
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design custom built dragheads or visors for dragheads