🌍 Designing for Compliance: How to Future-Proof Your Newbuild for EEXI and CII

My name is Davide Ramponi, I’m 20 years old and currently training as a shipping agent in Hamburg. On my blog, I take you with me on my journey into the exciting world of shipping. I share my knowledge, my experiences, and my progress on the way to becoming an expert in the field of Sale and Purchase – the trade with ships.

In the shipping world, compliance isn’t just about filling out forms anymore — it’s about engineering it into the hull.

With the IMO’s Energy Efficiency Existing Ship Index (EEXI) and Carbon Intensity Indicator (CII) now fully in force, shipowners face a critical question: how do you ensure your newbuilds meet — and maintain — these benchmarks over their entire service life?

It’s a complex challenge. Design decisions made today will determine not just your EEXI rating at delivery, but your CII trajectory for years to come. And balancing compliance with flexibility? That’s an art of its own.

In this post, we’ll explore how you can prepare your vessel during the design and construction phase to stay ahead of these evolving rules.

🔍 In this post, I’ll walk you through:

• 📐 How EEXI is calculated — and what it means for your design

• 📊 Strategies for building a strong CII trajectory

• ⚖️ Finding the sweet spot between compliance and operational flexibility

• 🧮 Simulation tools that test efficiency before steel is cut

• 🛳 Real examples of newbuilds that got compliance right from day one

Let’s set the coordinates — and build smarter for a carbon-conscious future. 🚢

📐 Understanding EEXI: Calculating Efficiency Before You Sail

What is EEXI?

The Energy Efficiency Existing Ship Index (EEXI) is a design-based metric. It assesses a vessel’s theoretical CO₂ emissions per tonne-mile, based on its engine power, design speed, capacity, and fuel type.

Although it was originally targeted at existing ships, the methodology also applies to newbuilds — especially those intended to replace older tonnage.

💡 Formula Snapshot:

EEXI = (CO₂ Emissions / Transport Work)Where:

• Emissions = engine power × SFOC × CO₂ conversion factor

• Transport Work = ship’s deadweight × design speed

Implications for Newbuild Design

To achieve a favorable EEXI score, shipbuilders and designers must focus on:

• ⚙️ Engine selection and derating

• ⚓ Hull form optimization

• 🌀 Propeller design and wake adaptation

• ⛽ Alternative fuels (e.g. LNG, methanol, ammonia)

• 🏁 Energy-saving devices (ESDs) like air lubrication or rudder bulbs

EEXI is frozen at delivery — so you only get one shot to meet the standard. The choices you make now will define compliance status for decades.

📊 CII: Designing for a Favorable Carbon Trajectory

If EEXI is your ship’s starting point, the Carbon Intensity Indicator (CII) is the report card that follows every year.

What is CII?

CII measures a ship’s actual carbon emissions per transport work on a real-time, annual basis. It’s a dynamic metric — affected by:

• Actual fuel consumption

• Distance traveled

• Cargo carried

Ships are graded from A to E, with a required annual improvement trajectory. Too many D or E ratings? You’ll face corrective action plans, or even commercial penalties.

Building for Better CII

While you can’t control voyage schedules at the drawing board, you can design with CII flexibility in mind.

Here’s how:

• ⚡ Design for slow steaming — optimize hull and engine for lower speeds

• 🔀 Flexible power plant — consider hybrid or dual-fuel systems

• 🎯 Install data-driven fuel monitoring systems from the start

• 🧠 Digital twins and simulation models to adjust behavior post-delivery

• 📉 Minimize hotel load — especially on cruise, RoPax, and offshore support vessels

💡 Tip: 

CII is especially sensitive to speed and distance — designing a vessel that performs efficiently at lower RPMs can make a major difference.

⚖️ Balancing Compliance with Operational Flexibility

While it's tempting to design solely for top efficiency, ships must operate in the real world — with market volatility, diverse routes, and changing cargo demands.

Key Design Trade-Offs:

• 🛠️ A derated engine may meet EEXI, but limit your ability to increase speed during high freight rates.

• 📦 A lightweight design improves efficiency, but may reduce versatility in cargo types or routes.

• ⚡ A fully electric auxiliary system reduces emissions, but raises CAPEX and maintenance complexity.

  
  

The key is to build adaptability into your ship:

• Use adjustable pitch propellers

• Include "ready for retrofit" wiring for future ESDs

• Choose engines with flexible load profiles

• Reserve space for future fuel tanks or battery systems

💬 Design goal: 

“Compliant today, competitive tomorrow.”

🧮 Using Simulation Tools to Validate Design Choices

Before committing to a build, shipyards and designers are increasingly using digital simulation environments to model and predict EEXI and CII outcomes.

🔍 What Can Be Simulated?

• EEXI score based on proposed engine + hull

• CII rating for a range of operational profiles

• Fuel consumption under various load conditions

• Weather routing + operational scenarios

• Impact of ESDs or hybrid systems on total emissions

🧰 Tools You Should Know:

• 🌐 DNV Veracity – includes CII simulator

• 💻 NAPA Fleet Intelligence – route-based efficiency prediction

• 🛠️ ShipCII™ – real-time voyage and design modelling

• 📊 ZeroNorth FuelOpt – for operational simulation and optimization

Using these tools before steel is cut ensures that:

• ⚖️ Compliance isn’t a guess

• 💸 Design decisions are tied to real-world ROI

• 📈 You can future-proof for CII deterioration over time

🛳 Case Studies: Building Compliance into the Blueprint

Let’s look at how real companies are already integrating EEXI and CII into the newbuild phase — and what we can learn from their approach.

📍 Case 1: Maersk’s Methanol-Ready Container Ships

Maersk’s new 16,000 TEU vessels are:

• Designed with dual-fuel methanol engines

• Optimized for slow steaming

• Fitted with digital fuel tracking systems

🎯 Outcome: 

CII projected to stay in A/B range for first 10 years — even with global trade fluctuations.

📍 Case 2: Eastern Pacific Shipping’s Aframax Tankers

EPS built a series of tankers using:

• CFD-optimized hull forms

• Engine derating for EEXI compliance

• Modular design to accommodate retrofitting of carbon capture tech

💡 Lesson: 

Even without exotic fuels, thoughtful design + simulation = high compliance at lower cost.

📍 Case 3: NYK Line’s LNG-Powered Car Carriers

These newbuilds feature:

• LNG dual-fuel engines

• Smart route optimization systems

• “CII-ready” design with future fuel tank space

📈 Result: 

Excellent EEXI scores + CII rating forecasted in B range with high variability tolerance.

🌐 What Comes Next? Designing for the Unknown

EEXI and CII are just the beginning. Over the next decade, we’ll likely see:

• 🌍 Fuel-specific metrics (e.g. methane slip tracking for LNG)

• 💡 Lifecycle-based CO₂ accounting — including upstream emissions

• 🚢 Zero-emission zone requirements in EU and select ports

• 📊 Live CII tracking used for real-time charter rates

• 🧾 Decarbonization-linked contracts that require verifiable performance

This makes future-proofing your newbuild not a bonus — but a business necessity.

✅ Conclusion: Compliance Starts with the First Sketch

EEXI and CII are not just regulatory hurdles — they are strategic design frameworks for building smarter ships.

Key Takeaways 🎯

📐 EEXI is your ship’s baseline — calculated before launch

📊 CII is your vessel’s operational score — updated yearly

⚖️ Smart design balances regulation with commercial agility

🧠 Simulation tools help de-risk decisions and optimize ROI

📍 Real-world builders are already seeing the benefits of early planning

If you’re planning a newbuild, the time to design for compliance isn’t next year — it’s now.

👇How are you approaching EEXI and CII in your fleet?

Are your design teams ready for what’s next?

💬 Share your thoughts in the comments — I look forward to the exchange!

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