What if you could simulate your fleet’s safe alternative fuel future?

Tuomas Häkkinen, Account Director, NAPA Safety Solutions.

Preparations for alternative fuels not only require having the right systems onboard or ensuring energy supply, but also understanding how these new systems might affect other aspects, such as ship design, operational stability as well as voyage planning. NAPA’s solutions can help take some uncertainties away by simulating those aspects, making your fleet’s transition smoother.

For decades, the shipping industry has been actively investing in innovations and alternative fuels to cut its carbon footprint. As a technology partner, we know how complex and challenging such decisions are, especially if you don’t have a complete picture of what’s to come. We’re, therefore, here to do our part in making this transition a little easier, and safer. Leveraging over 30 years of experience in ship design and stability, NAPA’s solutions can help evaluate the effect of switching to new systems and fuels, by simulating what such changes would mean for the vessel’s long-term operational and stability profile. This gives ship owners and operators the much-needed certainty and control when introducing new technologies, enabling them to move forward with confidence – all with the power of data and simulations.

In 2022 alone, 275 alternative-fuelled ships were added to the order book, as per DNV’s latest report; and this is not counting the battery-operated vessels, which have become sort of common in the short-sea, ferries and RoPAX segment.  

Alternative energy and low-carbon fuels are the top buzzwords now, but work on them began more than two decades ago. Flip back the pages of LNG-fueled-ship records, and you’ll see cross-fjord passenger ferry Glutra, with its four Mitsubishi gas engines, was already making waves in 2000. Eighteen years later, in 2018, Carnival Corporation’s AIDA Cruises made history as AIDAnova became the first 100% LNG-powered cruise ship. 

Fast-forward to today, LNG is almost mainstream, with 876 ships in operation and on order. In addition to LNG, batteries and carbon-capture systems, ship owners are already introducing green fuels such as biofuels and methanol – all these options are now available for both 2-stroke and 4-stroke versions in place with approvals for use. Other popular alternative-energy options still being investigated include ammonia, hydrogen, and fuel cells. Along with that, ship owners are also investing in niche solutions such as solar panels, rotor sails, air lubrication, and even direct-current hybrid ship grids.  

As no single technology can move the industry directly to zero emissions, it’s no secret that shipping companies will research and invest in an array of low- or zero-carbon technologies and alternative fuels in the coming future.  

The growing desire to diversify away from fossil fuels has even revived talk about nuclear energy as a future cruise propulsion system. “We’ve looked at nuclear, traditional nuclear fission. I won’t say there aren’t technical challenges. There are. But obviously, the biggest challenge has always been societal acceptance,’ said Tom Strang, a veteran safety analyst and SVP maritime affairs at Carnival Corp in a news article in Seatrade Cruise News. 

Also, just like LNG, the transition to new fuels won’t happen overnight. As Malte Zeretzke, Carnival Maritime’s Head of Research and Development, Decarbonization Unit, pointed out speaking at a Riviera Maritime Media Conference:

The milestone of 2050 for zero-emissions ship operations requires us to look at the possibility of doing large-scale demonstrations between 2025-2028.” 

Map out the best route forward 

Preparing for these new fuels not only involves having the right systems onboard or ensuring supply, but also understanding how these new systems might affect other aspects of operations, such as ship design, stability as well as voyage planning, routeing, bunkering and so on.  

Take batteries, for instance. They are heavy – twice as much as their fossil fuel equivalent, in the case of lithium batteries. Adding such weight may bring the ship closer to its maximum load mark, and if it was already being operated close to its maximum draft, there is a risk of overload. In practice, this could make it difficult to operate in environments with a low sea density, like the Baltic Sea.  

Looking at future fuels, the storage of hydrogen also requires at least double the space compared to conventional fuel oil, depending on the technology selected. Therefore, this too may alter the stability profile of a ship as the tank capacity would have to be increased and the tanks would also have to be isolated from other spaces.  

This is where NAPA’s solutions come in, helping ship owners, operators and managers pre-plan and simulate various scenarios – permutation and combination of technology versus various operational factors – to chart out the best route forward for their fleet. 

Based on data from actual operations at sea, together with an in-depth understanding of real onboard conditions and regulatory requirements, NAPA’s solutions can enable this transition at various stages – beginning with design and stability compatibility, to pre-calculating the impact of the new technology on their fleet’s performance optimization and safe operations, and finally, measuring and validating their operational models and choices. 

Here are a few ideas on what this could mean in practical terms: 

Stage 1: Check design and safety viability
How best to implement the new technology?

Changing fuels or installing a new propulsion system is likely to impact a ship’s structural strength, intact stability, damage stability, deadweight management, as well as voyage optimization possibilities. This is particularly important for retrofits, because big structural changes on a vessel that was initially designed to run on fossil fuels may alter its metacentric height, maximum draft, or usage of the liquid tanks. In other words, change one thing on a ship, and everything else is potentially affected, too. 

A typical example is a shipowner wanting to install scrubbers to reduce their Sulphur emissions – this involves installing new tanks and piping onboard the vessel, which typically impacts its stability parameters. In such a case, the increased weight in upper compartments affects the ship’s vertical center of gravity (VCG) and thus reduces safety margins.  

Similarly, when existing ships are retrofitted in the future to use ammonia as fuel on existing ships, this will require engine modifications and the installation of new fuel tanks and safety systems.  

But what if you could run simulations that predict how a vessel will behave before you even introduce a new technology on board?

With NAPA’s data analysis and modelling capabilities, we can test ahead, simulate, and pre-plan for the introduction of new power sources, be it engines, batteries, propulsion systems, or new fuels.” 

We do this by using the 3D model that was initially used to design the vessel in the first place – its “digital twin”, containing data on its unique structure and characteristics. With digital twins, NAPA’s solutions can help evaluate where new systems should be installed on a ship. Meaning, based on the different potential locations for batteries or new fuel tanks, NAPA design and stability tools can automatically calculate the impact of the added weight on the vessel’s stability parameters, including trim, heel and draft.  

For instance, in the above examples of installing scrubbers or new fuel tanks, the effects on the ship’s VCG can be modelled beforehand and checked against daily loading conditions data provided by NAPA Stability. What’s more, with NAPA Stability you can plan and manage the discharge from scrubbers. This helps ensure MARPOL conventions on low Sulphur emissions are followed, and no local restrictions on the discharge of washwater are broken. 

This helps owners test various permutations and combinations, and have the confidence that they’re making the optimal choices. 

Stage 2: Predict performance
What will this mean for my fleet’s performance? 

Considering that almost 90% of the ships worldwide are designed using NAPA’s software, the digital twins are automatically compatible with other NAPA tools onboard. Which means the digital twin continues to evolve during the vessel’s lifetime by fetching actual operational data that is crucial for modelling hyper-realistic operational simulations. For example, our NAPA Stability platform can feed it with information about a vessel’s typical operations, such as daily usage of the liquid and mass loads. Furthermore, NAPA Logbook and NAPA Voyage Optimization can enhance it with data on day-to-day operational logs, usual routes and weather conditions.  

This means simulations with digital twins can not only check the viability of technical aspects such as design and ship stability, but also can run simulations to determine operational aspects such as fuel usage, emissions, and more.

Thus, these simulations are not only a reliable way to check technical viability, but also a cost-effective way to predict the performance of the new systems.” 

Stage 3: Pre-plan Operations
How do I adapt my day-to-day operations for optimal results?  

NAPA’s tools can also help plan your voyages in advance and prepare operational models for the whole fleet. Take, for instance, methanol, which can set limitations on a ship’s operations, because it requires additional tank capacity on board. In some cases, ballast, fresh or grey water tanks will have to be converted to carry fuel, which has implications for the operations of a cruise ship. By using the ship’s digital twin, you can measure these impacts beforehand – and realize, for example, that you can no longer use your tanks the same way as before, and thus might have to bunker for water more often in your 7-day cruise than you had done in the past. 

Combining data from tools like NAPA Voyage Optimization, NAPA Stability and NAPA Logbook, crews and shoreside teams can run simulations based on real-time data on stability conditions, various ship logs, as well as voyage data such as AIS and weather conditions. This is supported by our cloud-based Fleet Intelligence platform, which enables shoreside teams to test-run various scenarios to optimize deadweight, hull and trim, routes, fuel consumption and emissions, and then pass on the plans to crew onboard for their perusal and action.  

Such holistic voyage planning ensures not only fuel optimization, but also ensures that safety requirements such as ship stability and “safe return to port” are met at the same time.” 

Stage 4: Benchmark and validate operations
Is my plan working? 

NAPA recognizes that capturing data for reporting and compliance purposes won’t be enough to get the full picture of your complex operational environment, let alone make analysis and decisions. We, therefore, provide the possibility to get a much more comprehensive data set in a standardized and error-free format, in real-time to the shoreside. With our customizable NAPA Logbook solution, any data can be recorded and transferred to the shoreside for further analysis. 

This will be crucial when new fuels are introduced, as this platform will be able to capture and provide insights and intelligence for both short (day-to-day operations) and long-term decision-making for further optimization. 

For instance, with our cloud-based tools, NAPA is in a unique position to provide one of the most holistic views of a fleet’s energy usage and operational activities. These can be used to measure, analyze and benchmark a wide range of operational activities such as fuel consumption per sea leg, real-time floating position, mass stores usage and cargo loading, tank fillings and real-time usage of liquids. Moreover, combining this with data from NAPA Logbook along with voyage optimization data such as weather data and AIS can help plan and optimize various other operational activities such as bunkering, cargo and voyage planning over time.  

Collaboration for a more certain future 

Passenger shipping is flying towards a zero-emissions future, quite literally. And clearly, there are many aspects of technology to consider, depending on the fleet type and operating profile, such as fuel characteristics, availability, and CAPEX and OPEX. That said, as Tom Strang from Carnival Corporation rightly points out in a news article:

Regardless of the specific fuel, the system is going to have to be safety-proven. Safety and sustainability are going to come hand in glove, and that’s really where the opportunities lie.”  

This is where NAPA’s tools come in. From stability data on how tanks and liquids (fuel and other) are used on board, our solutions can already make models for the use of new fuels with different densities. These simulations are not only a risk-free and reliable way to check the technical viability of various decarbonization technology, but also a cost-effective and time-saving testbed to predict the actual safety and performance capabilities of these new fuels. 

Going forward, the tools can help further refine the models and simulations as more real-life data becomes available. This means that sharing data and across-industry collaboration – between shipowners, shipyards, operators, technology providers, and academia – will be essential to pave the way forward to a safe zero-carbon future. NAPA hopes to support our customers along their sustainability journey, however ambitious their short-, mid-, and long-term goals may be.