Surv 11

A zero-carbon, pure methanol fuelled, vessel design 

Stephen Weatherley, Chartwell Marine

Decarbonising the marine industry is challenging, but critical.

At sea decarbonisation presents a challenge due to the long distances, adverse environmental conditions, and obvious lack of charging infrastructure.

Whilst there has been progress in developing hybrid diesel-electric ships, if we are to successfully reduce emissions from shipping the answer lies beyond (current) battery technology. The energy-density of leading Li-ion batteries is approximately 40x less than diesel, presenting significant weight issues for vessels needing to travel reasonable distances.

Hydrogen is a very effective fuel due to its energy density (around 2-3x that of diesel); however hydrogen is difficult to store effectively and safely. Methanol as a “feedstock” for storing and producing hydrogen safely (via reforming technology) promises a way of harnessing clean technology that can be used for long-distance operations.

In this study we will explore the adoption of methanol to hydrogen reformers as a potential power-plant for both leisure and commercial vessels.

We investigate the existing COTS technology and how it can be integrated aboard a small marine leisure platform. This platform will be hydrostatically representative of larger commercial vessels which will likely become technology adopters.

We explore the primary vessel design including propulsion system, fuelling system and electrical infrastructure that will need to be fitted aboard.

The various technologies are all available commercially; however they have been largely untested in vessel design. The equipment provides difficult challenges, including weight, geometry, effective engineering, and efficient conversion to energy.

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Procurement of a new heavy weather pilot boat for Milford Haven 

Steven Lee, BMT

The safe operation of pilot boats, in particular when operating in exposed conditions or in particularly heavy weather, requires that the boats and equipment provided is entirely fit for purpose. When procuring a pilot boat for such onerous operations, it is critical that a rigorous and well considered approach be applied such that a suitable capability is ultimately provided for use. Milford Haven Pilot Authority (MHPA) and BMT have worked together to procure a new bespoke heavy weather pilot boat and have evolved a process to achieve this.  Technical aspects have been reviewed in detail, starting with determination of the assessable key design requirements and operational characteristics. A tender process has been carried out whereby designers and yards have been provided with a detailed basis on which to fairly compete, and whereby MHPA have been given the tools to make appropriate dec  isions. In doing so, aspects such as cost-benefit analysis of different features, risk management and appraisal of differing technical solutions have been carried out. Furthermore, the involvement of the crews and the culture of the pilot organisation have been significant elements of the process, such that the vital human element of delivering a potentially high risk service has been fully involved from the start. This paper describes the procurement approach used, development of key vessel requirements, incorporating operator experience, a description of some of the debates held during the process, and the lessons learned.

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Investigation of hydrogen as part of a dual fuel approach for patrol and crew boats

James Calver, BMT

Hydrogen provides a promising green fuel option for some high speed light weight vessels engaged in activities such as surveillance, patrol, crew transfer or similar. It has the potential to be produced using entirely green and renewable energy sources and can be consumed in the fast-developing technology of fuel cells to potentially achieve a net-zero carbon vessel. However alternatively it can also be used in internal combustion engines with or without diesel as a pilot fuel, which when combined with exhaust after-treatment technology, also satisfies the strict IMO emissions targets in place around the world. Utilising hydrogen in a dual fuel propulsion system provides operators with the simultaneous benefits of reduced emissions, operational flexibility and a reduced impact of the hydrogen containment systems on the vessel design. Furthermore, a dual fuel system also provides the opera  tor with the flexibility to dampen  fuel price volatility by maximizing use of the most economical fuel. Challenges posed by the low energy density of hydrogen mean that significant use of this fuel remains currently unfeasible for smaller boats, however through direct comparison with a proven diesel-powered vessel, this paper demonstrates that utilising hydrogen as part of a dual-fuel application is viable with existing technology for a mid-size vessel, encouraging its application even in the initial phases of its technological development for such an application. This paper investigates the technology available, the potential implications from a naval architecture perspective and a broader commentary on the opportunities presented by this approach.

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Parametric Optimisation of a Hydrofoil for a 24m High-Speed Catamaran for Passenger Transportation 

Maddalena Minasi, Leading Edge Marine Engineering

The subject of this study is the preliminary design of a hydrofoil-supported catamaran, aimed at improving the environmental sustainability of this transportation mean. The work is built around the study case of a 24m passenger ferry operating on the Cannes-Nice-Monaco-Ventimiglia route. Following the definition of an operating profile, a comparative analysis of typical catamaran hull shapes has been carried out using both analytical tools and higher-order CFD RANSE simulations to compute overall resistance values. For the scope, a brief Verification and Validation exercise is included as well. To evaluate the benefit of adding a hydrofoil for resistance reduction, an initial investigation of the 2D profile characteristics is presented, followed by further optimisation for higher speed application. In the present study, the profile shape optimisation is carried out using the PARSEC parame  terization method, by coupling the panel method based XFOIL flow solver and DAKOTA software for the optimisation routine. A conclusive set of comprehensive 3D RANSE analyses of the complete system of hull and foil is then performed to validate the optimisation outcome.

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WaveReader – Predicting Impact Severities from Vessel Motion Analysis 

Shaun McCance, Naval Design Partnering

The representation of sea states is understood statistically and hence a breadth of wave heights can be predicted. The NDP WaveReader presents a helm aide for safeguarding personnel and augments the developing technology systems for autonomous operations by providing live indication of sea state from motions analysis allowing for a statistical determination of expected impact severities.
Preceding research and development, supporting the ongoing WBV considerations, has shown the very apparent benefits that a modest reduction in speed or a change in course in a seaway can achieved with regards to reducing exposure of personnel to aggregate shock and vibration events.  This has a significant carry over into all high-speed operations, crewed and autonomous where no single reliable technology, specific or adaptable, has been seen to exist for safeguarding small high-speed craft operating at speed with levels of autonomy in a seaway.

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Green Fuels Options Study for high speed marine vessels 

Chris Saunders, DSTL

The MOD operates a range of small boat based capabilities across a mix of roles.  The replacement of these capabilities will, in particular, present unique design challenges when attempting to meet net-zero targets while maintaining their desired military capability.

This paper reviews the approach and outputs of a study looking at green fuels options for these platforms.  It investigated the different options that could be utilised to propel future small naval platforms while aiming to achieve net zero emissions by 2050. It considered options including ammonia, hydrogen, battery based hybrid systems, and the use of synthetic hydrocarbons.

These options are considered against two key design conditions, a logistically constrained platform at 10 tonnes and a purely capability based view with minimal ‘iron triangle’ (payload vs. speed vs. range) constraints.
Based on our findings the study draws conclusions and makes recommendations for further research.

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Advances in Performance Prediction of Stepped Hulls 

Abbas Dashtimanesh, KTH Royal Institute of Technology

There has always been an interest in stepped hulls because of their high performance in comparison to other conventional high speed planing hull. Designers and boat builders have been orienting toward the multi-stepped hulls solution to ensure good dynamic stability, reliable seakeeping and operability at high speeds. However, the complexities in step design and lack of reliable and fast computational tools and methods have led to various problems in the design and operation of this kind of high-performance hulls in both calm water and waves. To this end, we have conducted a series of studies based on mathematical modelling, numerical simulations and experimental tests to understand the physics of the stepped hull and the complexities of step design. Accordingly, we have developed computer programs that can be implemented for performance prediction of stepped hulls in both calm water and regular waves. This paper summarizes all our efforts during the past 5 years and introduces the developed mathematical models, numerical setups as well as our comprehensive stepped planing hull series. The obtained results from our previous studies including resistance, dynamic trim and wetted surface in calm water as well as motion in waves are presented and the accuracy and efficiency of developed methods is evaluated. Moreover, the paper discusses the effects of various step parameters on hull performance and shows how our developed tools can be used for future design.

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Safe and Green Search and Rescue Craft 

Nickan Ghahramani, Newcastle University

At the 72nd Marine Environment Protection Committee (MEPC) meeting in 2018, the International Maritime Organization (IMO) adopted a strategy to reduce the carbon footprint of global shipping by 50% by 2050 compared to the 2008 baseline. Although not explicitly regulated under IMO’s instructions, the RNLI as the UK and Ireland’s search and rescue organisation with more than 400 lifeboats, is aiming to achieve zero-carbon emission before 2050. As part of their efforts to achieve this, they are working with Newcastle University on research which aims to identify alternative low and zero carbon powering systems for the RNLI’s craft.
In response to the anticipated demand for engine systems to run on low-carbon fuels, engine manufacturers have started developing alternative energy systems. However, at this stage, they are typically aimed at large shipping vessels and therefore not enough activities for the decarbonisation of small craft have been provided. There are often weight and volume constraints as the main challenging factors in designing new systems for small craft. This research reviewed various fuels towards low and zero carbon emission for the RNLI craft. Hybrid systems including fuel cells and battery packs will be considered to satisfy running long driving cycles. A volume and weight comparison, carbon footprint, and cost analysis of the alternative fuel propulsion systems for the RNLI’s targeted vessel are the emphasis of this study.

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Full scale validation of a frequency domain gyroscope roll stabilising model on various Fast Crew Supply vessels.

Geerten Poen, Damen RD&I BV

Roll motions on board can have a big impact on human comfort and operational limits. This happens when a ship is underway, but especially at zero speed when the inherent hull roll damping is low. This impacts Fast Crew Supply (FCS) vessels in particular, as they offer both transit and offshore transfer operations to their passengers. A common problem is that people get seasick once the vessel is stationary at an offshore location and it starts rolling. Roll reduction devices have been around for a long time, of which the gyroscope has the advantage of working independently of ship speed, in contrast to some other types, e.g. traditional stabilising fins. The roll stabilising performance of gyroscopes can be approximated by using a frequency domain model. In this paper the frequency domain model is fed by strip theory output, enabling a wide range of wave headings and speeds to be handled.
The model is then validated with full scale trial results combining three different gyroscopes models, made by two different manufacturers and applied on three different FCS vessels.

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Understanding and Mitigating Shock and Vibration in Flexible Inshore Lifeboats 

Thomas Coe, RNLI

This paper presents the results of a multi year programme of work to understand the motions of the RNLI’s D Class Inshore Lifeboat and mitigate the effect of these motions on lifeboat crew.
The D Class is the RNLI’s most numerous asset and as a high performance inflatable craft is capable of generating high levels of shock and vibration.
Sea trials demonstrated however, that these impacts were fundamentally different to those experienced on other vessels, with high levels of shock and vibration experienced at the stern of the vessel.  The results of full scale trials both at sea and in a towing tank environment are presented to investigate the effect of vessel flexibility on motions.
The paper then presents the testing of novel shock mitigation solutions to reduce the effect of impact on the craft occupants. The results of both instrumented sea trials and operational trials are presented.

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Pro-active shock mitigation: reducing injury and improving performance of craft and crew, by minimising impacts before they happen.

Joseph Salmon, Salmon Power Sports

Passengers and crews onboard high-speed boats are frequently exposed to excessive and dangerous levels of impact and whole-body vibration (WBV), resulting in a high risk of acute and chronic injury. Much work has already been done to better understand the effects of impact and WBV, and there are studies currently underway which seek to determine the boundaries of what can realistically be considered “safe” levels of exposure.

However, it may be some time before this research amounts to greater protection for those on the water; a 2000 study of US combat crewmen revealed an injury rate of 64.9%, while a 2020 study of French combat crewmen showed a 66.7% acute injury rate, indicating that 20 years of improved understanding had not yielded tangible results for crews. This may even be an optimistic view of the injury rate, given that a retroactive questionnaire of combat crewmen demonstrated an injury rate of 90%.

Impact exposure is also proven to negatively impact the performance of the crew, and by extension the vessel itself. A NATO report on impact-induced injuries aboard fast craft revealed that 70% of crewmen felt that they experienced “impaired capacity” to perform their assigned roles onboard due to impact and WBV. The helm may voluntarily slow down in order to reduce the risk of greater impacts at higher speeds, but given the time-critical nature of military and rescue operations, this is an equally undesirable outcome.

The most common means of protecting crews against injury is the suspension seat, which dampens impact levels experienced by the occupant. These can be effective in protecting crewmembers, but there can be a risk of complacency when specifying and designing a vessel, as suspension seats should be considered a key pillar of an holistic and multi-level shock mitigation strategy, rather than being treated as a “silver bullet”.

The “holistic” approach to shock mitigation is not a new idea, however it is formed upon the premise that large impacts, and the resulting injuries, are an unfortunate but inevitable consequence of travel at high speed or in rough conditions. The focus has therefore been mainly on technologies which reduce the effects of impact, such as suspension seating or vibration-dampening decking, or behavioural changes such as reducing speed wherever possible.

We propose that a central pillar of an holistic approach should be to attempt to minimise in the impact itself, which we refer to as “proactive” shock mitigation, through technologies such as dynamic ballast systems. Whilst impact at speed will never be reduced to zero, sea trials demonstrate that utilising dynamic ballast to shift LCG forward and generate inertia at the bow of an RNLI Atlantic 75 can reduce average impact levels by ~50%, and reduce larger impacts by up to ~70%. This synergises with the use of suspension seats, further minimising the risk of seats “bottoming out”.

By taking a preventative rather than a curative approach to impact, we can not only improve the wellbeing of passengers and crews, but also directly improve their effectiveness, with real-world benefits for both military and rescue operations.

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Developing a sustainable and comfortable cruise vessels

Marnix de Monchy, Ijgensinnig

Over the past few decades, cruising has grown in popularity as ships have become larger to accommodate more passengers and operate as efficiently as possible. As prices dropped, cruising became accessible to people with average incomes.

Traditional cruisers avoid these ships because they miss the luxury and exclusivity of cruising. With above average financial resources, their budget does not yet allow for private yacht charter. The growth of this group has created a market potential for a new generation of cruise ships.
The design of these ships is based on extensive market analysis and takes into account increasingly stringent regulations to reduce the environmental footprint.
This paper will show the concept development of a comfortable cruise ship with a minimum ecological footprint.

By analyzing 50 cruise ships and some yachts, the most appropriate comfort/price ratio is determined. In addition to the analyses, the environmental impact is taken into account in order to create the highest possible level of comfort on board.

The proposals for alternative materials and systems on board are based on the reduction of environmental impact. Propulsion energy is not included in this paper as other parties are working on its development.

The combination of these two aspects results in a new type of cruise ship that meets the requirements of the early adopters of exclusive cruising.

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Avoiding Aluminum HSC Hull Damages During Dry Docking and Ocean Transport – Operator’s Perspective

Deniz Tugay, University of Southampton

Dry docking and lifting of aluminum vessels carry unforeseeable risks when it comes to laying them on shipyard supports, slipway cradles, and heavy lift cargo ship decks. Due to the nature of aluminum, vessels must be supported on bulkhead frames or ordinary frames stated in their document plans. Support points must have complete matching accuracy to the corresponding keel blocks. Although this can be easily achieved with floating dock and syncrolift operations, several challenges arise during placement of the vessel on the submerged cradles due to wake coming from passing by vessels, sudden wind and tide changes, and poor underwater visibility. Similar challenges apply also when the vessel is being lifted by self-geared heavy lift carrier slings, or carried by submersible carriers. For craft not designed with lifting lugs, the issue becomes more complicated when heavy lift and travel lift slings occupy the very same frames on which the vessel will be seated on, when lifted ashore or above a cargo ship’s deck. Hence the shipyard or the carrier maybe left with no choice but to use different frames other than those designated for laying the craft. Aluminum craft operators would prefer designers to review more options to increase the number of frames that the vessel can be laid upon, and frames designated as load points to be equipped with reinforcements extended between adjacent frames to tolerate minor misplacement caused by external factors. This presentation will outline key risks associated with aluminum HSC dry docking, investigate the main causes of hull damage, and lay out a practical operational and design solution based on a real life case study carried out.

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A Loitering Optionally Crewed High Speed Rescue Vessel For Remote Region Rescue Response

Emil Jonze, Docksta Varvet and John Dalziel, Dalhousie University

SOLAS requires National Governments to establish, operate and maintain SAR facilities as are deemed practicable and necessary for their Search & Rescue Regions (SRRs).  Some of these SRRs are very large, may have heavy weather conditions and, in addition, may be remote from bases for rescue resources.

What’s the best way to comply with this requirement and provide the necessary resources to save lives at sea?  Ships are expensive to maintain on station, relatively slow and impacted by heavy weather, fixed wing aircraft have limited time on station and limited rescue capabilities, and helicopters have limited range and time on scene and limited survivor capacity.

One solution could be stationing on site a high-speed, uncrewed (optionally crewed) seagoing vessel.  This vessel could be strategically located remote from other sea rescue resources but near areas of potential incidents.  It would require endurance to maintain its location on station, while reserving sufficient fuel to proceed at high speed to the site of a serious incident, remain on site for the required length of time, and then proceed to a safe place of refuge with the survivors. As an uncrewed vessel, its speed of response would NOT be constrained by health and safety considerations of crew members.

This presentation outlines an area of risk in the North Atlantic and then proposes a novel solution to the problem of rescue response.  Current status of rescue response and marine incidents is analyzed clarifying the need for rescue resources.  The application of a Loitering, Optionally Crewed, High Speed Rescue Vessel will be evaluated, considering the many technical and operational issues involved.  In addition, the issues of integrating this vessel with other SAR assets, to improve maritime safety, will be considered.