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The authors are solely responsible for the content of this report. Material included herein does not represent the opinion of the European Community, and the European Community is not responsible for any use that might be made of it.
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The heavy-duty device is made from stainless steel, uses all-welded construction and is robust enough to withstand being towed through marine sediments. Importantly, the sensing element consists of a single short probe around which fluid can flow easily with no risk of material entrapment. Unlike some other types of density meter, the Mudbug uses no radioactive materials, so there are no environmental hazards involved. A further advantage is that with no moving parts, maintenance is minimal.
This technique is still in its infancy on the Humber Estuary, but with accuracies of +/- 1% being quoted, the ability to have real-time density data versus depth profiling and the ability to minimise maintenance dredging on the Humber Estuary, the implications may be huge. This measure is also not limited to the Humber Estuary and can be used in both shallow and deep water. There is still a lot to learn to maximise the potential to reduce the needs for dredging, which have both economic and ecological benefits and can reduce hydromorphological impact within the estuary.
In one outing, the Mudbug mud density probe saved Associated British Ports (ABP) over £70,000 in dredging costs and enabled the ABP survey team quickly and accurately to detect the depth at which the mud reached the density of fluid mud.
The Mudbug was rigged on a davit and towed through the waters of the river Humber at Immingham Outer Harbour. The bathymetric survey produced by running the Mudbug simultaneously with a standard 33 kHz echo sounder showed an average 0.5m difference between the results from the Mudbug and those obtained from the echo sounder.
The Mudbug also enabled the survey to be completed much more quickly than was possible with earlier density measurement methods. Using the Mudbug, it took no more two hours to gather the data for the chart and another two hours to process it, compared to the previous method of density probing, which would have taken two days to collect that amount of data.
The Mudbug's multifunctional transducer incorporates density, temperature and pressure (depth) sensors plus all interface electronics. The unit is calibrated at the factory, so on-site calibration is not necessary. Once at the desired location the transducer is deployed using a support line, and measurement can start as soon as the probe is submerged. The weight of the transducer ensures that it will easily sink into silt layers. Readings are taken approximately five times a second and, as a large number of measurements can be made very quickly, it is possible to cover a wide area in a short time.
Density is measured in the range 800 to 1600 kg/m³ with an accuracy of ±1% at depths up to 100 metres. The Mudbug uses its own pressure sensor to determine the depth of the transducer, thus allowing real-time density versus depth profiling.
Density, depth and temperature measurements are output by the Mudbug as serial data which can be imported directly by third-party hydrographic surveying software such as HYPACK. Alternatively, the DataPod Connection Unit can be connected to a USB port on a PC or laptop, in which case no separate power supply is required as the instrument is powered simply through the USB connection. The proprietary NaviTrend software supplied with the system shows real-time measurements in both tabular and graphic form on the PC/laptop, while logged data can be exported to Microsoft® Excel™ for further analysis.
Easily integrated into existing survey equipment, the Mudbug can be deployed in minutes and provides reliable data straightaway, with minimal setup and no risk to the environment.
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Deployment of Mudbugs
Table of content
- 1. Measure description
- 1a. Description of the issue and measure
- 1b. Status of the Measure
- 1c. Monitoring
- 1d. Monitoring results
- 2. Execution of main effectiveness criteria
- 2a. Effectiveness according to development targets of measure
- 2b. Impact on ecosystem services
- 2c. Degree of synergistic effects and conflicts according to uses
Description of the issue and measure
The deployment of the Mudbug is a new technique in the Humber Estuary and is used to determine the navigable depth in ports, harbours and estuaries by measuring the density of fluid mud . It is an easy-to-use “plug-and-play” system consisting of a rugged, towable transducer connected by an umbilical cable to DataPod Connection Unit on the surface.The heavy-duty device is made from stainless steel, uses all-welded construction and is robust enough to withstand being towed through marine sediments. Importantly, the sensing element consists of a single short probe around which fluid can flow easily with no risk of material entrapment. Unlike some other types of density meter, the Mudbug uses no radioactive materials, so there are no environmental hazards involved. A further advantage is that with no moving parts, maintenance is minimal.
This technique is still in its infancy on the Humber Estuary, but with accuracies of +/- 1% being quoted, the ability to have real-time density data versus depth profiling and the ability to minimise maintenance dredging on the Humber Estuary, the implications may be huge. This measure is also not limited to the Humber Estuary and can be used in both shallow and deep water. There is still a lot to learn to maximise the potential to reduce the needs for dredging, which have both economic and ecological benefits and can reduce hydromorphological impact within the estuary.
In one outing, the Mudbug mud density probe saved Associated British Ports (ABP) over £70,000 in dredging costs and enabled the ABP survey team quickly and accurately to detect the depth at which the mud reached the density of fluid mud.
The Mudbug was rigged on a davit and towed through the waters of the river Humber at Immingham Outer Harbour. The bathymetric survey produced by running the Mudbug simultaneously with a standard 33 kHz echo sounder showed an average 0.5m difference between the results from the Mudbug and those obtained from the echo sounder.
The Mudbug also enabled the survey to be completed much more quickly than was possible with earlier density measurement methods. Using the Mudbug, it took no more two hours to gather the data for the chart and another two hours to process it, compared to the previous method of density probing, which would have taken two days to collect that amount of data.
The Mudbug's multifunctional transducer incorporates density, temperature and pressure (depth) sensors plus all interface electronics. The unit is calibrated at the factory, so on-site calibration is not necessary. Once at the desired location the transducer is deployed using a support line, and measurement can start as soon as the probe is submerged. The weight of the transducer ensures that it will easily sink into silt layers. Readings are taken approximately five times a second and, as a large number of measurements can be made very quickly, it is possible to cover a wide area in a short time.
Density is measured in the range 800 to 1600 kg/m³ with an accuracy of ±1% at depths up to 100 metres. The Mudbug uses its own pressure sensor to determine the depth of the transducer, thus allowing real-time density versus depth profiling.
Density, depth and temperature measurements are output by the Mudbug as serial data which can be imported directly by third-party hydrographic surveying software such as HYPACK. Alternatively, the DataPod Connection Unit can be connected to a USB port on a PC or laptop, in which case no separate power supply is required as the instrument is powered simply through the USB connection. The proprietary NaviTrend software supplied with the system shows real-time measurements in both tabular and graphic form on the PC/laptop, while logged data can be exported to Microsoft® Excel™ for further analysis.
Easily integrated into existing survey equipment, the Mudbug can be deployed in minutes and provides reliable data straightaway, with minimal setup and no risk to the environment.