Slower Arrivals, Lower Emissions: Cargill Shows How Port Queues Can Deliver Fuel Savings

Ships waiting outside congested ports burn time and money, but better arrival coordination could turn that waiting period into an opportunity to cut fuel consumption and emissions.

Research involving Cargill Ocean Transportation and the Global Maritime Forum found that adjusting vessel speeds to match berth availability reduced estimated emissions by up to 11% on individual ballast voyages. The results suggest that smarter scheduling, rather than new onboard technology alone, can improve operational efficiency.

Three Ports, Different Approaches to Arrival Planning

The study examined 16 ballast voyages involving three ports in Brazil and Australia. Each location used a different approach to coordinate vessel arrivals, demonstrating that the benefits depend heavily on port conditions, waiting times and the flexibility available to ship operators.

At Cargill’s grain terminal in Santarém, Brazil, a customized virtual notice of readiness arrangement allowed vessels to reduce speed while retaining their position in the terminal queue.

Across 10 voyages, estimated emissions fell by 222 tones of CO₂, representing a 3% reduction in emissions from the ballast legs. The arrangement achieved these savings without disrupting berth schedules.

At Australia's Port of Newcastle, an existing vessel arrival system produced estimated emissions reductions of 6% to 11% across three voyages. Favourable currents also allowed vessels to drift towards the port with their engines stopped. However, two other vessels recorded no savings because berths were available when they arrived.

The findings highlight a critical operational point: slow steaming delivers the greatest benefit when it replaces unnecessary waiting, not when a vessel already has a berth available.

Blue Visby Trial Demonstrates the Benefits of Slow Steaming

At Albany in Western Australia, a Kamsarmax bulk carrier used the Blue Visby Solution to coordinate its arrival. The vessel reduced speed from 8.6 knots to 7.4 knots, generating estimated savings of 10.73 tones of fuel and 33.4 tones of CO₂.

That represented a 9.6% reduction in ballast-leg emissions. Cargill and grain handler CBH Group also shared the bunker savings under their arrangement.

The trial illustrates how digital coordination and commercial agreements can work together. Rather than racing towards a port and waiting offshore, vessels can adjust their passage to arrive closer to the time a berth becomes available.

The Global Maritime Forum estimates that commercial vessels spend around 4% to 6% of their operating year — approximately 15 to 22 days — waiting outside ports. Better coordination could reduce this idle time without necessarily extending the overall cargo transportation schedule.

Why Wider Adoption Remains Difficult

The technology is only one part of the solution. The study identifies several commercial and operational barriers that can prevent ships from slowing down.

Shipping contracts and terminal procedures do not always reward flexible arrival planning. Shipowners may pay for the fuel, while terminals or cargo interests receive much of the operational benefit. Charterparty clauses, commodity contracts and hold inspection requirements can also complicate virtual arrival arrangements.

The evidence also has limitations. With only 16 voyages examined, the results cannot establish industry-wide savings. Most participating bulk carriers were already operating near their minimum practical speeds, limiting the scope for further reductions.

Achieving larger savings will require vessels capable of sustained ultra-slow steaming, clearer contractual provisions and berth-planning systems that reward coordinated arrivals instead of encouraging ships to reach port as early as possible.

Why This Matters

• For shipowners and operators: Lower speeds can reduce bunker bills and emissions, particularly when vessels would otherwise spend hours or days waiting offshore.
• For deck officers and chief engineers: Voyage planning increasingly involves balancing engine performance, weather, currents, arrival windows and fuel consumption rather than simply maintaining the fastest practical passage.
• For charterers and terminal operators: Shared savings arrangements can align commercial incentives and encourage cooperation between parties that traditionally manage separate parts of the voyage.
• For maritime decarbonization: Better scheduling offers a practical emissions-reduction measure that can be implemented alongside alternative fuels, energy-efficiency upgrades and other operational improvements.

The Bottom Line

Cargill’s trials show that some of shipping’s fuel savings may come from changing when ships arrive, not just how efficiently they sail. Scaling the benefits will require coordinated decisions between vessels, ports, terminals and commercial partners.