Ship Design
The maritime industry is currently navigating one of the largest regulatory transitions in modern shipping history. Regulations such as FuelEU Maritime and the EU ETS are intended to accelerate decarbonisation and drive more energy-efficient operations.
However, regulations do not only influence fuel choices and operational costs. They also influence how ships are designed.
One clear example is the growing focus on the 5000 GT threshold.
Today, vessels below 5000 GT are currently outside the main scope of the EU ETS and FuelEU Maritime. As a result, the threshold has increasingly become a major commercial design parameter for many shipowners and newbuilding projects.
This is a rational response to the framework the industry operates within. Shipowners naturally adapt to regulations in order to remain competitive.
But from a ship designer’s perspective, it also raises important questions.
Design Driver
In many vessel segments below 5000 GT, particularly within regional and short-sea shipping, there is now strong commercial pressure to maximise cargo intake while remaining below the regulatory threshold.
That changes design priorities.
Every cubic metre becomes commercially important. Cargo capacity competes directly with machinery spaces, technical systems and accommodation areas. Balancing cargo flexibility, fuel efficiency, operational capability and regulatory compliance within a limited GT envelope is becoming an increasingly complex design challenge.
This does not necessarily lead to poorer ships. In many cases, it drives innovation and smarter space utilisation.
But it can also create unintended consequences.
Factor Risks
One of the areas most affected by GT optimisation is often accommodation and onboard living environment.
And this comes at a time when the shipping industry is already facing major crewing challenges.
The industry is competing for qualified officers and crew in a global market where expectations regarding working conditions, comfort, privacy and onboard wellbeing are continuously increasing. At the same time, operational demands continue to grow.
Fatigue, mental wellbeing and crew retention are no longer “soft” issues. They are directly linked to operational performance, safety and long-term competitiveness.
The effects are not limited to accommodation alone. Increasing pressure on enclosed volume can also result in more compact and crowded engine room arrangements, making onboard maintenance and daily operations more difficult and potentially increasing safety risks for the crew.
In some cases, space limitations may also reduce flexibility for environmental installations and operational systems such as settling tanks, treatment systems or future retrofit solutions.
This creates a potential contradiction.
If regulations indirectly incentivise minimising enclosed spaces and accommodation quality in order to remain below a certain GT threshold, the industry risks moving in the opposite direction of what long-term crewing sustainability and operational practicality require.
Advantage
Another important aspect is how the threshold may influence fleet renewal.
In some cases, older vessels below 5000 GT may gain a relative commercial advantage simply by remaining outside parts of the regulatory framework, despite having significantly higher fuel consumption and emissions compared to modern newbuildings.
This raises an important question:
Are current regulatory thresholds always aligned with actual environmental performance?
There is a risk that the industry starts optimising around a regulatory number rather than around overall operational efficiency and long-term environmental performance.
Clarity
There are ongoing discussions regarding future adjustments to the regulatory framework and whether the 5000 GT threshold should remain unchanged.
From a ship design perspective, timing matters enormously.
Ships being designed today will likely remain in operation for decades. If the market invests heavily in vessel concepts optimised around the current threshold, only for the framework to change later, there is a risk that the industry moves down a path that may ultimately prove commercially or operationally suboptimal.
With possible future discussions around extending parts of the framework to smaller vessels, clarity is needed sooner rather than later.
Perspective
At FKAB, we work extensively with vessel concepts in the sub-5000 GT segment and see first-hand how regulatory thresholds increasingly influence vessel design decisions.
A few additional cubic metres allocated to cargo may directly affect accommodation quality, engine room arrangement, fuel system integration or operational flexibility. In many projects, the design process becomes a continuous balancing act between commercial optimisation and long-term operational practicality.
From a design perspective, net tonnage could in some ways be a more relevant parameter than gross tonnage, as it is more directly linked to cargo carrying capacity rather than enclosed spaces required for crew wellbeing, workable machinery arrangements and environmental systems. At the same time, such an approach would also create different implications depending on vessel type and operational profile.
We believe this creates an important industry discussion.
If regulations unintentionally push vessel designs towards minimising onboard living quality, reducing maintainability or delaying fleet renewal, there is a risk that some outcomes move counter to the broader long-term goals of sustainability.
Because sustainable shipping is not only about emissions.
It is also about designing ships that people want to operate, maintain and work onboard for decades to come.
Work with FKAB Marine Design to pioneer the next generation of sustainable shipping