Current measuring navigational buoy one buoy, two purposes

Rijkswaterstaat 2Current measuring navigational buoy Improving information supply to large ships entering the Port of Rotterdam by combining navigational and measurement facilities in a buoy Peter Verburgh, Rijkswaterstaat Information Supply division (CIV)

Rijkswaterstaat 3Current measuring navigational buoy Outline of presentation Rijkswaterstaat, a brief company overview Situation Present data supply Reasons for renovation Why a buoy? What buoy to use? The deployment The data Summary, conclusions and time for discussion.

Rijkswaterstaat 4Current measuring navigational buoy Rijkswaterstaat Part of the Dutch Ministry of Infrastructure and the Environment Responsible for design, construction, management and maintenance of: the main road network the main waterway network the main watersystems

Rijkswaterstaat 5Current measuring navigational buoy Central Information Services CIV provides reliable and fit-to-business information for Rijkswaterstaat Peter is project manager at CIV

Rijkswaterstaat 6Current measuring navigational buoy Situation Very busy shipping area Large ships need information to enter Rotterdam harbor safely

Rijkswaterstaat 7Current measuring navigational buoy Present information supply Meteo Waves Current from 2-D model Current from pole Tide

Rijkswaterstaat 8Current measuring navigational buoy Present information supply Wind Waves Current from 2-D model Current from pole Tide

Rijkswaterstaat 9Current measuring navigational buoy Reasons for renovation Better predictions 3D information instead of 2D Reduction of maintenance costs Present measurement pole “Maasmond” out of order

Rijkswaterstaat 10Current measuring navigational buoy Future information supply Meteo Waves Tide Current from 3-D model Surface current from HF-radar Current from buoys

Rijkswaterstaat 11Current measuring navigational buoy Why a buoy? Relatively low cost solution compared to pole (100k vs 1000k€) Relatively short time to put into practice (8-10 months vs 2 yrs) Easy to change the location Low cost of ownership (maintenance is done on-shore) Disadvantages: Vulnerable Little space for solar panels, therefore very limited power No fixed location, it moves on its anchor The ADCP is constantly moving

Rijkswaterstaat 12Current measuring navigational buoy What buoy to use Commercially available measurement buoys Specifically designed measurement buoy Lesson learned from previous development in Zeeland Operational requirements Decision: Buoys will be based on ‘Zeeland’-buoy

Rijkswaterstaat 13Current measuring navigational buoy The production An existing contract for navigational buoys was used (no tender) Order based on functional rather than technical specifications Supplier is responsible for proper functioning Rijkswaterstaat is responsible for data-connection (on-line!) Rijkswaterstaat is responsible for deployment

Rijkswaterstaat 14Current measuring navigational buoy The production Two buoys, one spare ‘measurement-core’ Flotation segments from France (Mobilis) Central cylinder made in the Netherlands (Rombouts) Electronics designed and made in France (Mobilis) ADCP and UMTS/GPRS supplied by Rijkswaterstaat CIV Put together in the Netherlands (Mobilis/Rombouts)

Rijkswaterstaat 15Current measuring navigational buoy The deployment From a.l. to b.r: The vessel ‘Rotterdam’, the buoy ‘Maas-Oost’ in the crane of the ‘Rotterdam’, both buoys and spare core on deck of the ‘Rotterdam’, the buoy ‘ODAS-MV’ on location

Rijkswaterstaat 16Current measuring navigational buoy The data First brief impression: looks acceptable… Comparison with model output: reassuring! Evaluation versus separate measurement with shipborne ADCP ongoing

Rijkswaterstaat 17Current measuring navigational buoy The data Difficulties encountered: One of the beams seems to reflect from the anchoring chain Occurrence of ‘moving bottom’ may reduce accuracy Complex data conversion suspect to introduce (timing)errors Settings are location-dependent and have to be done very carefully

Rijkswaterstaat 18Current measuring navigational buoy Summary A navigational buoy can be succesfully transformed into a online measurement platform, while retaining its navigational purpose. Vertical current profiles can be measured from a buoy Take into account operational difficulties It is not as ‘cheap’ a solution as some managers would like it to be

Rijkswaterstaat 19Current measuring navigational buoy Questions / discussion Thank you for your attention! …Time for questions and discussion