Recent constructions of large sea locks in the Netherlands at IJmuiden and Terneuzen have been accompanied by extensive hydraulic research, including physical scale model tests which took into account the effects of density differences across the lock heads during leveling operations. The case study presented here compares the situations and results from the studies of the two locations, and shows the importance of density effects in an accurate assessment of the hydrodynamic forces on the vessels and subsequently the forces on the mooring lines. Supposedly small differences in the local boundary conditions at the two locations lead to very different results, owing primarily to the differences in propagation of the density currents. Numerical models do not as yet predict this with sufficient accuracy. This further underlines the importance of doing extensive preliminary hydraulic investigations when designing large new shipping locks.

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During berthing operations vessels use their bow thruster(s) to improve their manoeuvrability, making them less dependent on the assistance of tugboats. The jet from a bow thruster reflects on the quay wall. It is directed towards the bottom where it reflects, causing high flow velocities over the bed. This may scour the nearby bed when it is left unprotected, leading to instability of the quay wall. Over the years, the shipping industry has been developing continuously, characterized primarily by the upscaling in size of inland- and sea-going vessels. As a result, vessels have more power and larger thruster diameters leading to higher hydraulic loads on quay walls and bed protections of berthing facilities. The most common type of bed protection is rip-rap (partially) penetrated with concrete. However, due to the complex flow field of the reflected jet, the decay profile of the near-bed flow velocities is unknown. This results in uncertainties in the design of bed protections and the required width of these protections that must be penetrated with concrete. In this research, the decay of the near-bed flow velocity in perpendicular direction to the quay wall induced by a 4-channel bow thruster is researched. The eventual goal is to provide a better indication to what extent the bed protection must be penetrated with concrete. Field measurements have been conducted in the North Sea Port of Gent with the Somtrans XXV, one of the largest inland vessels in the Netherlands. The flow velocities near the bed, induced by the bow thruster, have been measured with Acoustic Doppler Velocimeters (ADV), Acoustic Doppler Current Profilers (ADCP) and Ott meters (Ott). The results from the flow velocity measurements have been analysed on three main parameters: influence of the applied bow thruster power, the distance between the measurement instrument frame and the bow thruster and quay wall clearance. The highest flow velocities are measured near the quay wall in the order of 1 m/s reaching up to a maximum of 1.8 m/s. Further away from the quay, the flow rapidly declines towards a more constant level of approximately 0.3-0.4 m/s. To define the maximum load on the bed, the mean flow velocity plus three times the standard deviation is used resulting in a maximum load ranging between 1.6-2.8 times the mean horizontal flow velocity. The Dutch and German guidelines for determining the near-bed flow velocities generally overestimate the measurement results. In addition, the dependency of the Dutch method on the total travelled distance by the jet, based on the sum of the quay wall clearance, the height of the bow thruster above the bed and the distance x from the quay wall, are not reflected in the measurement results. It is recommended that this extensive and unique data set acquired through the field measurements in Gent is further used to analyse the flow field of a reflected jet on a vertical quay wall by validating numerical and scale models. Combining these three different methodologies will contribute to a better understanding of this phenomenon with the eventual goal of optimizing the design of bed protections.

In the port of Ostend a discharge sluice is going to be constructed as part of an enforced dike ring. The proposed location of this discharge sluice is close to an already existing marina, the Royal Yachtclub Oostende (RYCO), and hindrance is expected regarding the outflow of the sluice in marina direction. When designing the sluice, an optimal balance has to be found between acceptable flow velocities in the downstream area and the capacity of the discharge sluice. It is therefore very important to be able to determine resulting flow patterns.

Formulas and rules of thumb found in literature are not sufficient to determine the resulting flow pattern of this system due to the complex geometry, including a pile row for flow velocity reduction. Other studies have shown that numerical models could simulate flow patterns of discharge sluices with much detail. However, a lot of detail in the results also requires much computational time. An example of a detailed numerical software program that is able to simulate the complete three-dimensional flow field is COMSOL Multiphysics 5.6 (COMSOL). Although it provides the most detail, simulating the flow in the entire area of interest (including the RYCO) for a complete tidal cycle in COMSOL would take too much computational time.

The objective of the present study is therefore to investigate the possibilities of determining the flow pattern downstream of a discharge sluice using a numerical method that requires less computational time but has sufficient accuracy to determine the potential impact of a discharge sluice on nautical activities.

In the present study, two options are considered to determine the flow field downstream of a discharge sluice. Method COMSOL-D3D is a coupled numerical method of a COMSOL and a coarser Delft3D-FLOW 4 (D3D) model. The other option, method D3D, uses only a D3D model and the sluice outflow is schematized by means of the general discharge relation.

As validation of the results is not possible due to a lack of measurement data, the methods are applied to a simplified case. The flow pattern resulting from each method is compared to the results obtained with a so-called baseline method. This method consists of modelling the entire domain with only a detailed numerical model, COMSOL. This is possible since, for validation purpose, the domain of the simplified case is relatively small and only stationary conditions are considered.

In conclusion, there is a lot of potential in the use of both methods in predicting the flow pattern downstream of a discharge sluice. They produce for the simplified case flow patterns similar to those obtained with the detailed method. Moreover, both methods require relatively little computational time compared to a full 3D simulation, method D3D requires the least amount. However, there are a number of conditions for the application of both methods.

The methods cannot be applied in the direct vicinity of the discharge sluice where the flow is highly three-dimensional. If one is interested in the flow in the first meters after the outflow opening or around the pile row, for example for designing the bottom protection, the two considered options are not sufficiently accurate. The flow in this area is too complex to simulate in a D3D model. In this case it is recommended to model the situation completely in COMSOL or a model similar to COMSOL. Furthermore, method D3D can only be applied if the sluice system is simple enough to correctly determine the discharge coefficient analytically/empirically and to simulate the effect of the pile row with a simplification in D3D. It is possible to accurately determine the effect of the pile row on the flow in this study with a schematized porous plate in D3D. Further research must show whether this applies to all types of pile rows.

For method COMSOL-D3D it is important that a correct coupling is made between both models. Here it is important to gradually impose the flow rates in the D3D model. Furthermore, the coupling should be made before the predicted point at which the jets starts deflecting towards the side but downstream of the area at which three-dimensional flows caused by the pile row are present.

It is important to note that due to a lack of validation data there is an uncertainty in the results following from the model approaches. Further research and the use of validation data must show how accurate the results of the considered methods are.

In this research method D3D is applied to the Ostend case. It becomes clear that flow rates exceed predetermined limits for safe operation in the marina. This applies to the entire marina and a large part of the time that the discharge sluice is discharging in marina direction. Measures will therefore have to be taken to prevent this. It is recommended to use method COMSOL-D3D to investigate the optimization between flow velocities in the marina and the discharge capacity. This is due to the fact that the design of the discharge sluice is expected to become much more complex and as a result the discharge coefficient is no longer easy to determine using formulas from literature.

In recent years, several logistic optimisation models have emerged as powerful tools to assess and optimise the planning, costs, and workability of marine operations. Nevertheless, these models often rely on two underlying assumptions: (1) the significant wave height and peak wave period adequately describe (directional) wave fields, and (2) these two parameters sufficiently describe the conditions causing weather downtime. However, little is known about how these underlying assumptions affect the reliability of logistic optimisation tools. This study, therefore, presents an alternative model that integrates response motions of vessels and turbine structures into a logistic optimisation tool to address and expose the implications that follow from using these assumptions. A case-study approach, on two recently realised offshore wind farm projects, showed that integrating response motions results in, up to 10%, less favourable workability conditions. Further analysis on the data showed that it is crucial to include the two-dimensional wave energy distribution to expose more complex sea states that induce weather downtime. Moreover, a failure analysis approach found that the conditions inducing downtime events are more accurately described by response motions instead of sea state parameters. Therefore, the findings of this study suggest that integrating response motions into logistic optimisation models improves the reliability of the model estimates. Besides, this study suggest that the industry’s approach potentially overestimates the true workability and, therefore, imposes unnecessary operational risks. Hence, the results of this study demonstrate the importance of integrating hydrodynamic engineering knowledge into the assessment and optimisation of project planning, costs, and workability.

Ships in rivers create waves and these can have a negative impact on fish habitats along the river banks. A modelling study is carried out to investigate how these ship-induced waves can be damped in groyne fields by making structural modifications to the groynes. For this purpose, different types of openings (notches) are applied to the groynes. Next, hydro-ecologic indicators are used to assess the impact of notching of groynes on fish habitat suitability. The results suggest that relatively simple modifications can significantly improve the ecological value of the groyne fields.

During mooring operations, ships tend to make an extensive use of bowthruster in order to minimize the need for tug assistance. Jet caused by transverse thrusters directly impinges quay walls, and can cause scour on the bed, therefore threatening structural stability of quay walls. Presence of vertical quay walls induces reflection of bowthruster's jet, further complicating the already complex flow field. Despite extensive research has been conduced on free flow, several knowledge gaps are still present regarding propeller induced flow when confined, for instance by a vertical quay wall. In this research, focus is on flow field on the bottom of a vertical quay wall induced by channel-type bowthrusters, which are commonly used for inland vessels. Field measurements have been conducted at the Antarcticakade, Ports of Rotterdam, using inland vessel MTS Vorstenbosch. The vessel is equipped with a 4-channel Veth Jet type bowthruster system. Use of a combination of Acoustic Doppler Velocimeters and Acoustic Doppler Current Profilers allowed measurements of flow velocities on the bottom of the quay. Data from the measurements has been analysed to investigate influence of distance between outlet and quay wall, and keel clearance, on the flow pattern at the bottom. Results have then been contextualized within the literature framework, and their impact on design of bottom protection according to most used guidelines has been assessed.
The results of this field measurement showed mean flow velocities near the quay wall generally in the order of magnitude of 1 m/s, with the exception of one test, where mean flow velocities in the order of magnitude of 2 m/s were recorded. This relatively low mean flow velocities were often correlated with large turbulent fluctuations, leading to values of relative turbulence intensities higher than the ones found in literature, and sometimes even equal to 1. Comparison with the theoretical calculations of velocities according to Dutch and German methods suggested by PIANC, showed both methods to be conservative if compared with data from most tests. Furthermore, it appeared that both formulae’s sensitivity to wall and keel clearance was not reflected by the data. Similarly, results from this measurement showed that the flow generated by simultaneous use of two bowthrusters was characterized by velocities on the bed lower than expected according to the guidelines. Recommendation would be to use either linear superposition or to multiply by square root of n (where n is the number of used propellers) when considering the use of multiple propellers, but this was not reflected by most of the data. However, two of the tests taken into exam represented an exception to these general observations: ADV1, the instrument nearer to the quay wall, recorded velocities higher than the theoretical values for tests 12 (use of bowthruster 2 at high water) and 22 (use of both bowthrusters simultaneously at low water). Results from this study showed how the use of a 4-channel bowthruster system induced a flow on the bottom of a vertical quay wall which is mainly divided in two zones. Near the quay wall is where the highest velocities have been measured, and where the flow is strictly influenced by use of the bowthrusters. There is a return flow beneath the ship, which is dissipated in the space of few meters. Underneath the suction points of the bowthrusters, it is the inflow to determine the flow characteristics on the bed. In this research, the extent of the bowthruster-induced flow was found to be less than 14 m from the quay wall. The instrument hereby located, in fact, didn't record velocities which were affected by the use of bowthrusters. This research represents a step towards filling the knowledge gaps about use of bowthrusters at a vertical quay wall. The unique dataset collected can be used in the future for validating numerical or on-scale models, working for a better understanding of the phenomenon and a more accurate and optimized design of bed protections.

Moored vessels in harbours around the world are affected by waves penetrating into the port basin. Hydraulic conditions can lead to severe vessel motions that influence the (un)loading efficiency and can even lead to the failure of fenders and mooring lines, creating unsafe situations for operating staff and
A DMA is a chain of numerical models that computes motions of moored vessels due to wind, currents or waves. It is used to model the behaviour of moored ships to evaluate operational conditions and assess the effect of structural or operational measures. The most computational costly model in the DMA chain is the wave penetration model, which computes local wave field, speeding up this part of model chain can reduce time and costs of such DMA's.
In this research, the complex wave model is replaced by a computationally efficient alternative and the main research question reads:
How can a mild-slope wave model be used for the ship motion calculation on ships moored in ports and what are the benefits and limitations?
The research is split up into two parts: 1) Development of the coupling method and evaluating its application based on academic test cases and 2) Applying the coupling to the case study of La Coruña and assessing its suitability.
A practical and efficient method to extract wave components from the wave penetration model is the r-DPRA tool developed by Deltares. The developed method is applied to the case study of the port of La Coruña. Two separate moments in time of the same bulk carrier are modelled: one with moderate offshore wave conditions and one with more severe conditions.
In the measured time series of the surge and sway motions, a clear low frequency can be found. Similarly, in the simulated time series of the surge and sway motions; both in moderate and heavy cases no low frequency wave patterns can be found. A schematic approach is used to include the long waves in the wave model and ship motion model and this approach caused a low frequency wave pattern to arise and leads to more accurate significant motions.
The comparison between the measured motions and modelled motions demonstrated the complexity of modelling real life events. As the surge and sway motions are caused by second order effects that are not included in the applied linear wave model, it is recommended to apply the developed workaround to schematically include this low wave forcing. The result of this research demonstrates the potential for the development method.
Before directly applying the method, it is recommended to test the suitability of the method on a more fundamental case, this reduces uncertainties related to real life measurements and stronger conclusions about the performance of the coupling can be drawn. Moreover, the coupling should be tested for a case where the 2nd order low frequency wave forcing is negligible. As it is confirmed in this research that the developed method is not suitable for modelling non-linear 2nd order low frequency waves.

The port authority of the Port of Talcahuano has the desire to expand the port. The goal of the expansion is to increase the berth space and attract more vessels, thus increasing their throughput. This report is an advise to the port authority on the possibilities of expanding. Four preliminary port designs aremadewith the requirement of the ability to berth two 180mvessels. AMulti-Criteria Analysis has been used to determine the most suitable scenario. The detailed design for this scenario is composed of a quay design, a dredging plan, an earthquake and tsunami impact analysis, market prospect analysis and a financial analysis. A technical design for port expansion, as well as a market strategy has been advised to the port authority.