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The need to reduce emissions from shipping is urgent. Potential future fuel candidates include hydrogen and methanol. This study has attempted to draw a fair comparison between these two fuel types by adopting a bottom-up approach to quantify fuel consumption and emissions. A 10,755 nm voyage undertaken by an LNG carrier was used as a case study. Models were developed for a hydrogen fuel cell energy system and a reformed methanol fuel cell energy system. Simulations calculated the fuel requirements and tailpipe emissions for each option. However, as neither hydrogen nor methanol is naturally occurring, the energy required to produce these fuels should also be considered. Three production methods have been modelled: wind turbines with electrolysis; grid supply with electrolysis; steam methane reforming. Thereafter, the total lifecycle emissions for each fuel option have been calculated and compared to the existing vessel. Typically, this is referred to as well-to-wake emissions, but for green fuels wind-farm-to-wake may be more appropriate. Results showed that switching to methanol reduced tailpipe emissions by a maximum of 8.3% and wind-farm-to-wake emissions by 18.8% but only if the fuel can be produced entirely from renewable energy. A liquid hydrogen fuel cell energy system produced zero wind-farm-to-wake emissions and required 33.3% less renewable energy than methanol.

HM Government’s “Clean Maritime Plan” (2019) targets zero emission shipping to be “commonplace” by 2050 and that all new ship orders by 2025 should be capable of delivering zero emission propulsion.1 For these goals to be achieved, significant investment in alternative fuels is required. 2. The long-life span of large ships requires an early start to both retrofit of existing vessels as well as preparing the ground for a transition to new build zero carbon ship from 2025 onwards. 3. Large scale shipping is a challenging sector to decarbonise, primarily due to large energy demands coupled with limited onboard storage capacity. Alternative fuels are imperative to eliminate both greenhouse gas emissions and harmful pollutants that damage the health of seafarers and port communities. 4. Hydrogen is a viable candidate to provide emission-free propulsion and is cleaner and easier to produce without emissions than other alternatives being considered (such as ammonia or methanol). All combustion technologies are relatively inefficient and even those using zero carbon fuels (e.g., ammonia) lead to polluting emissions (e.g., NOx). Consequently, immediate research and innovation into electro-chemical approaches for powering large ships and other heavy-duty industrial uses are essential. 5. Our main policy recommendations are:  Invest in the research and development of hydrogen production, storage and transfer technologies for ships, ports and large industrial users.  Develop and introduce evidence-based safety regulations and protocols specific to alternative fuels and in particular hydrogen.  Increase subsidies for zero emission/zero carbon hydrogen production (such as water electrolysis).  Further research into the development of fuel cells or fuel cell/battery hybrid systems for ships and other major industrial off-grid applications.

Decarbonisation of the shipping industry is necessary. Two potential low-emission fuels for long distance international shipping are hydrogen (H2) and ammonia (NH3). Using data from an LNG tanker, approximations were made for energy requirements based on delivered power, with the maximum consumption for a single voyage being 9270 MWh. Calculations were made for the required volume, mass and variable cost for several fuel types. Results showed that H2 required volume was 6550 m3 and 11040 m3 for liquid and pressurised gas storage respectively. H2 is frequently dismissed for mobile applications due to low volumetric density, however these volumes are not unrealistic. Ammonia has several desirable characteristics, but also has low gravitational energy density increasing the overall ship mass by 0.3% to 3.7%, negatively affecting performance. Batteries are too large, heavy and expensive for long distance applications. Both hydrogen and ammonia have potential, but require further research before becoming viable.

A method of calculating the effects of a bulbous bow on delivered power has been developed. The method takes the full scale measured shaft power of a vessel with a bulbous bow, and compares this to a calculated calm water shaft power of the same vessel without a bulb. This enables the performance of the bulbous bow to defined in terms of a change in shaft power. The shaft power of the bulb-less vessel is calculated using the Holtrop and Mennen statistical prediction. Many of the inputs to Holtrop and Mennen are draft dependent, therefore these variables are calculated for the measured draft of the full scale data, using geometrical and empirical formula. Propulsive efficiency is calculated via draft corrected wake and thrust deduction (empirically) and assuming a Wageningen B-series propeller. The effective power prediction of Holtrop and Mennen is then converted to shaft power via the calculated propulsive efficiency. The performance of the bulbous bow is defined as the change in residual shaft power due to the addition of the bulbous bow. This change is made non-dimensional to remove the effects of hull shape and a similar performance formula to that of Kracht [1]. Two power effecting bulbous bow parameters, as defined by Kracht [1] ,the depth parameter coefficient and vessel Froude number are shown to widely range over the operational profile of 7 sister LNG vessels. The performance of the bulbous bow is calculated over these ranges. It was found that the bulbous bow performance improves in general with increasing Froude number, and that for a given Froude number range there is an optimal bulb-depth parameter for ballast and laden conditions. Once the performance of a bulbous bow over an operational profile has been identified, it can enable the vessel operator to make operational changes, in order to ensure the bulb is working in optimal power-reducing conditions. Additionally, this performance indicator could be used to decide as to the requirement of a re-design of the bulbous bow. The performance of this bulbous bow is found to be dependent on the full-scale measurement accuracy and the accuracy of Holtrop and Mennen to predict effective power. A future sensibility analysis of this method is needed to understand the reliability of the bulb performance value. Despite this, this method still shows the expected trends of a bulbous bow from the literature, and can therefore be used for operational optimisation, via ensuring the bulb depth parameter is in an optimal condition for the given Froude number range.

This paper presents a method to normalise the shaft power data recorded at high-frequency to derive the baseline (calm water power) curves by applying a shaft power correction. This is carried out using two correction methods for added power due to waves developed for sea-trial measurements - namely, STAWAVE-1 and STAWAVE-2. The calm water power is then obtained as a difference between the measured power and the added power. The results obtained using this normalisation method is compared to filtering techniques. It is shown that the differences between the predictions using the two methods are minimal, with a maximum of 6% at the normal operational speed of the vessel. The normalising method retains about 40 % of the total data, nearly 4 times more than the datasets retained with filtering methods.

Wave breaking is one of themost violent phenomena of air-water interface interactions, producing strongturbulence with air bubbles, water droplets, jets and sprays. These phenomenacommonly occur in ship flows and are one of the main sources of underwaternoise and white-water wakes. The investigation of these phenomena is importantin ship and ocean engineering. OpenFOAM is a valuable open source and continuummechanics library for building multi-physics simulations and its use growingrapidly in both research and industry. This paper investigates the ability ofOpenFOAM to simulate non-linear waves, wave transformation and breaking with k-휔 SST-RANSmodel through the study of wave generation and propagation over a submergedbar.In the first instance an empty numerical wave flume is constructed. In earlierversions of OpenFoam, water wave modelling was developed by various softwarepackages, such as olaFoam, waves2Foam and IHFoam. Among them, waves2Foam,developed by Jacobsen et al. (2012), is probably the most common toolkit usedin ship-wave interaction simulations. However, these packages are no longersupported in the newest standard release of OpenFOAM 5.0.0 (OF500), due toinstallation, maintenance and coding standard problems. A new framework of waveModelis instead supported for wave generation. In this study, the waves2Foamimplemented in OpenFOAM 3.0.1 (OF301) and waveModel in OF500 are employed andcompared to examine their abilities and stability in modelling of regular wavepropagation.Based on the numerical wave flume, the waves2Foam model is used to simulateboth non-breaking and breaking waves. The numerical results are compared withthe experimental measurements by Beji and Battjes (1993). Several previous studiesof breaking waves using waves2Foam have only performed numerical calculationsfor breaking waves on a beach profile (Jacobsen et al., 2012; Jacobsen et al.,2014; Zhou et al., 2017). The effect of obstacles on wave propagation wasmodelled by Gadelho et al. (2014), but they only reported non-breaking wavetransformations. In the current study, non-breaking and spilling breaking wavesgenerated by Stokes waves of different incident wave heights are investigatedwith waves2Foam.Finally, the study is extended to investigate the effects of convection schemeson the multiphase simulations. Four different schemes are tested for theirability to predict regular wave propagation as well as wave transformation andbreaking over the bar.

In order to monitor the performance of a vessel in calm seas it is important to ensure that the operational parameters are not biased by weather conditions. This paper makes a comparison between the relationship of true wind speeds obtained from on-board anemometer measurements and hindcast MetOcean data with the wave heights obtained from the MetOcean data. The insights obtained from the correlations between wind and waves is used to make a comparison calm water model derived from ‘wind-wave’ filtering and data filtered using only the wind speed. Finally, the increase in shaft power with respect to wind speed and wave heights for discrete intervals is presented. The results presented indicate that an average decrease of 4-5% in shaft power is seen when including an additional wave filter in the calm water model. However, this discrepancy improves when a stricter wind speed filtering is used.

A report on the impact of Brexit on UK shipping, maritime legal services, fisheries and trade by the Institute of Maritime Law and the Southampton Marine and Maritime Institute of the University of Southampton.