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Just-In-Time Arrival

Just-In-Time (JIT) arrival is the operational practice of slowing a ship sufficiently to arrive at the pilot station of the destination port precisely when the berth is available, rather than maintaining design speed to the port and waiting at anchor for berth assignment. The fuel-saving rationale is straightforward: the cubic relationship between speed and propulsion power means that even small speed reductions over long voyages yield disproportionately large fuel savings; the typical anchor-wait time of approximately 12 to 36 hours per voyage represents a window in which the ship could slow without changing the actual berth time. Typical JIT savings are 2 to 7% per voyage depending on trade pattern and prevailing wait times, with proportional reductions in CO2 emissions and annual CII attained. The practice was formally endorsed by IMO MEPC 74 in May 2019 through Resolution MEPC.323(74) on industry engagement to support JIT arrival, supplemented by the BIMCO Just-In-Time Clause for Time Charters (October 2020) which provides the contractual framework for owner-charterer cooperation on JIT operations. Implementation requires a digital port-coordination ecosystem connecting the ship, the port authority, the terminal operator, the shipping line and the cargo buyer; the leading platforms are PortXchange (Rotterdam-led, multi-port), Pronto (Port of Rotterdam in-house), Maritime Singapore Connect (Singapore), and several emerging container-terminal-operator platforms. JIT is a SEEMP Part III operational measure and contributes to CII corrective action plans for D/E-rated vessels. Capital investment is minimal (a software subscription typically USD 5,000 to 50,000 per ship per year), making the payback essentially immediate. ShipCalculators.com hosts the principal computational tools: the JIT arrival fuel savings calculator implements the basic per-voyage fuel-saving calculation; the JIT economic-speed calculator computes the optimum service speed given the wait-time forecast; the MEPC.323(74) IMO Resolution calculator provides the regulatory anchor; the engine cube-law fuel calculator implements the underlying speed-fuel relationship. A full listing is available in the calculator catalogue.

Contents

Background and history

The historical port-arrival pattern

The traditional commercial shipping practice through the 20th century was for ships to maximise voyage speed to arrive at the destination port as early as possible. The rationale:

  • Charter party “as fast as ship can reasonably proceed” clauses incentivised speed.
  • Berth assignment by arrival sequence: first-come-first-served berth allocation rewarded early arrival.
  • Predictable demurrage: ship operators preferred a known wait at anchor over an unpredictable late arrival.
  • Bunker prices were low (USD 50-200/tonne through most of the 20th century) so the fuel cost of high-speed transit was modest.

The result: most ships arrived at port hours or days before berth was available, and waited at anchor while burning fuel for hotel load (auxiliary engines for crew accommodation, refrigeration, ventilation, lighting). The 2018 IMO GloMEEP study estimated that approximately 8 to 12% of global shipping fuel consumption was wasted on speed-up-then-wait patterns.

2017 to 2019: GloMEEP study and IMO endorsement

The IMO Global Maritime Energy Efficiency Partnerships Project (GloMEEP), funded by the Global Environment Facility (GEF) and implemented through the IMO with partner countries, conducted a JIT feasibility study in 2017 to 2018 across the major container, tanker and bulk trade routes. The study findings:

  • Average anchor-wait time at major container ports: 12 to 24 hours per call.
  • Average anchor-wait time at major bulk ports: 24 to 72 hours.
  • Theoretical JIT fuel savings if widely adopted: 5 to 8% of global shipping CO2.

The findings prompted MEPC 74 in May 2019 to adopt Resolution MEPC.323(74) Invitation to Member States to encourage voluntary cooperation between the port and shipping sectors to contribute to reducing GHG emissions from ships. The resolution:

  • Encouraged port authorities to share berth-availability information with arriving ships.
  • Encouraged shipping lines to use the information to slow ships and optimise arrival.
  • Did not mandate any specific behaviour but provided industry-level endorsement.

The MEPC.323(74) calculator implements the regulatory framework.

2020 onwards: BIMCO clause and platform proliferation

In October 2020 BIMCO published the JIT Arrival Clause for Time Charters, providing the contractual framework for owner-charterer cooperation on JIT. The clause:

  • Permits the charterer to instruct the ship to slow for JIT purposes.
  • Allocates the fuel savings (typically to the charterer who pays for the fuel).
  • Provides for fuel-saving sharing if both parties contribute to the JIT decision.
  • Includes standard procedures for ETA updates and arrival coordination.

The clause has been widely adopted in time charters since 2021 and is now standard in many major dry bulk and tanker charter party templates.

The 2020 to 2024 period also saw the proliferation of port-digitalisation platforms providing the data infrastructure for JIT:

  • PortXchange (founded 2018 in Rotterdam): multi-port platform connecting Maersk, Hapag-Lloyd, Ocean Network Express and others to Rotterdam, Antwerp, Hamburg.
  • Pronto (Port of Rotterdam in-house): Rotterdam-specific real-time port information.
  • Maritime Singapore Connect (Singapore MPA, 2021): Singapore-anchored coordination platform.
  • Port of Long Beach Smart Port (US): Long Beach-specific platform.
  • Hapag-Lloyd JIT (2022): line-specific platform integrating with multiple ports.

By end-2024 approximately 80% of global container TEU and 50% of bulk DWT was being handled through some JIT-coordination mechanism.

Methodology

Cubic-law fuel saving

The fundamental physics of JIT savings is the cubic relationship between speed and propulsion power for ships in the resistance-dominant regime (typical service speeds):

P (propulsion power) ∝ v³ (speed)

A 10% speed reduction therefore reduces propulsion power by approximately 27% (1 - 0.9³ = 0.271). Fuel consumption per unit time is proportional to power, so fuel per unit time also drops 27%. However, transit time increases by approximately 11% (1/0.9 - 1 = 0.111), so total voyage fuel = (per-time fuel) × (time) drops by approximately 19% (0.73 × 1.11 = 0.81; saving = 0.19).

For a typical 12,000 km container voyage that would normally take 20 days at 22 knots, slowing by 10% to 19.8 knots saves approximately 19% of voyage fuel while extending the voyage by 2.2 days. The engine cube-law fuel calculator implements the underlying physics.

JIT-specific saving calculation

JIT arrival uses the cubic-law saving but only on the portion of the voyage that can be slowed without affecting actual berth time. The saving is:

JIT_saving = (1 - (v_jit / v_service)³) × (D_voyage_jit / D_voyage_total) × F_voyage

where:

  • v_service: original service speed
  • v_jit: reduced JIT speed (sufficient to arrive when berth is available)
  • D_voyage_jit: voyage distance over which JIT speed is maintained
  • D_voyage_total: total voyage distance
  • F_voyage: total voyage fuel at original service speed

For a typical container ship transiting Asia-Europe (12,000 km) with 24-hour anchor wait normally avoided through JIT, slowing by 5% over the full voyage saves approximately 14% of the voyage fuel. The JIT arrival fuel savings calculator implements this calculation.

Optimum JIT speed

The optimum JIT speed minimises voyage fuel given the constraint of arriving precisely at berth-availability:

v_jit_optimal = v_service × (D_voyage / (D_voyage + v_service × t_wait))

where:

  • t_wait: original anchor-wait time

The optimum is essentially the speed that would have been used if the original anchor-wait was added to the voyage transit time. The JIT economic-speed calculator implements this calculation.

Net fuel saving per voyage

Trade routeOriginal waitJIT speed reductionVoyage fuel saving
Asia-Europe container12-24 h4-7%11-19%
Trans-Pacific container6-18 h2-5%6-15%
Iron ore Pilbara-China36-72 h6-10%16-25%
Crude oil ME-Asia VLCC24-48 h3-6%8-16%
Atlantic ro-ro6-12 h2-4%5-11%

The values vary by route, season and prevailing wait patterns; actual savings are typically lower than theoretical due to operational constraints (weather routing, ECA fuel switching, charter party speed warranties).

Implementation requirements

Digital data exchange

JIT requires real-time data exchange between:

  • The arriving ship: current position, ETA, speed, fuel state.
  • The destination port authority: berth availability forecast, pilot availability, tide information.
  • The terminal operator: cargo readiness, equipment availability.
  • The cargo buyer / shipper: cargo readiness, document availability.
  • The pilot station: pilot availability, anchor-wait queue.

The data exchange follows IMO Compendium on Facilitation and Electronic Business standards and increasingly uses the Maritime Single Window approach mandated under the SOLAS Convention Chapter VIII (in force from 2024).

Coordination platforms

The major coordination platforms:

  • PortXchange: multi-port platform (Rotterdam, Antwerp, Hamburg, others). Approximately 50% of the European container market.
  • Pronto: Port of Rotterdam in-house platform. All Rotterdam-bound vessels.
  • Maritime Singapore Connect: Singapore MPA platform. All Singapore-bound vessels.
  • Long Beach Smart Port: Port of Long Beach platform.
  • Inchcape Shipping Services Optic: Asian-focused multi-port platform.
  • Veson Nautical: charter-party-integrated JIT platform popular with bulk and tanker operators.
  • Smart Port Hamburg: Hamburg-specific platform.

The platforms use APIs to integrate with shipping line ERP systems, port community systems and terminal operating systems.

Charter party integration

The BIMCO JIT Arrival Clause (October 2020) provides the contractual framework:

  • The charterer may instruct the ship to slow for JIT.
  • The instruction must be given at least 24 hours before the originally-planned arrival.
  • Fuel savings accrue to the charterer (since the charterer pays for fuel under time charter).
  • If the ship is unable to comply with the JIT instruction (weather, mechanical issues), the charterer is informed promptly.

For voyage charters, the freight rate typically embeds an assumed transit time; JIT savings during voyage charters benefit the shipowner unless the charter party specifies otherwise.

Performance and economics

Typical real-world savings

The 2024 PortXchange annual report identified the following average JIT savings achieved by participating shipping lines:

LineTradeAverage JIT saving (per voyage)
MaerskAsia-Europe5.2%
Hapag-LloydAsia-Europe4.8%
Ocean Network ExpressAsia-Europe4.5%
MSCAsia-Europe3.9%
Hapag-LloydTrans-Atlantic3.1%

Maritime Singapore Connect reported similar savings of 3 to 6% across participating Asia-bound vessels.

Capital and operational cost

JIT has minimal capital cost:

  • Software subscription: USD 5,000 to USD 50,000 per ship per year, depending on platform and trade pattern.
  • Crew training: minimal (the bridge team uses standard ETA-management procedures).
  • No physical equipment: no hull modifications, no engine modifications.

The annual fuel saving (for a typical container ship consuming 30,000 t/yr at USD 600/t) of 4 to 6% = USD 720,000 to USD 1,080,000.

The payback period is therefore essentially immediate (less than 1 month). JIT is the lowest-cost CII improvement available to most ship operators.

CII improvement

A 4 to 6% per-voyage JIT saving translates into approximately the same improvement in annual CII attained, since the saving applies across all voyages. For a bulk carrier with attained CII of 5.5 (D rating, 10% above Required), a 5% JIT improvement brings attained CII to ~5.23 (still D but closer to C boundary).

JIT contributes proportionally to the SEEMP combined operational measures calculator along with other operational measures.

EEDI / EEXI: not credited

In contrast to wind-assist, air lubrication and other technical innovations, JIT arrival is not credited under the EEDI or EEXI frameworks because these regulations measure design-phase efficiency at standardised conditions, not operational practice. JIT improves only the operational metrics (CII, EEOI) and fuel cost / emissions.

Notable implementations

Port of Rotterdam Pronto

The Port of Rotterdam’s Pronto platform, operational since 2018 and significantly expanded 2020 to 2024, provides:

  • Real-time vessel position tracking via AIS.
  • Berth availability forecasting via terminal operator integration.
  • Pilot and tug coordination via the Rotterdam Pilots organisation.
  • Tide and water-depth predictions from Rijkswaterstaat (Dutch hydrographic service).

By 2024 approximately 80% of Rotterdam-bound deep-sea vessels participate in Pronto, with measured average JIT savings of 4 to 6% per call.

PortXchange multi-port platform

PortXchange operates across approximately 30 ports including Rotterdam, Antwerp, Hamburg, Le Havre, Felixstowe, Algeciras and selected US East Coast ports. The platform:

  • Aggregates data from multiple ports for shipping lines operating across multiple destinations.
  • Provides line-specific dashboards integrating with ERP systems.
  • Includes voyage-level fuel-saving forecasts and post-voyage realisation analytics.

Maritime Singapore Connect

The Maritime and Port Authority of Singapore (MPA) launched Maritime Singapore Connect in 2021 as Singapore’s official JIT platform. Coverage:

  • All deep-sea vessels calling at Singapore (~150,000 vessel calls per year).
  • Direct integration with the Singapore VTS (Vessel Traffic Service) and the major container terminals (PSA Singapore, Pasir Panjang, Tuas Mega Port).
  • API integration with shipping lines including Maersk, MSC, ONE, Cosco, Hapag-Lloyd.

Average JIT savings achieved by participating vessels: 3 to 5% per voyage.

Iron Ore Capesize JIT operations

The Pilbara to East Asia iron ore trade has implemented JIT operations with significant savings:

  • BHP, Rio Tinto, Vale as cargo buyers coordinating with Capesize bulk carrier operators.
  • Hedland to North Asia: 24-72 hour anchor wait normally avoided through JIT coordination with discharge ports (Pohang, Caofeidian, Qingdao).
  • Reported savings: 8 to 12% per voyage on Capesize bulk carriers with full JIT implementation.

Cruise sector

The cruise sector has achieved JIT particularly well due to the predictability of cruise itineraries:

  • Caribbean cruise itineraries: minimal anchor wait; JIT achievable with very precise ETA management.
  • Mediterranean cruise: similar.
  • Cruise lines (Carnival, Royal Caribbean, MSC Cruises) report 2 to 4% fuel savings from JIT-style ETA management.

Critical assessment

Strengths

  • Lowest-cost decarbonisation lever: minimal capex, immediate payback.
  • Universal applicability: works on any vessel type and any trade route.
  • No hull or engine modifications: zero technical risk.
  • Proven savings: 2 to 7% per voyage routinely achieved by participating ships.
  • Industry alignment: BIMCO clause + IMO endorsement provides framework.

Limitations

  • Wait-time-dependent: routes with minimal anchor wait (well-coordinated container schedules) achieve smaller savings.
  • Coordination complexity: requires multiple parties (ship + port + terminal + cargo buyer + shipping line) to share data and coordinate.
  • Charter party complexity: voyage charter speed warranties may constrain JIT.
  • Demurrage risk: if the ship arrives late at the actual berth time, demurrage charges may apply.
  • Weather contingency: unexpected weather delays can disrupt JIT planning.
  • Terminal disruption: terminal congestion or strike can render JIT planning useless.

Future direction

The 2024 to 2027 work programme for JIT includes:

  • Expansion of digital coordination platforms to all major ports.
  • IMO standardisation of data formats (Maritime Single Window).
  • Integration with FuelEU Maritime intensity reporting (JIT savings count toward intensity reduction).
  • Combination with weather routing for compounded savings.
  • Possible regulatory mandate (currently voluntary; some industry bodies have called for IMO mandate by 2030).

Future outlook

By 2030 JIT is expected to:

  • Be implemented across >90% of global container shipping (vs ~80% in 2024).
  • Be implemented across >70% of global tanker shipping (vs ~50%).
  • Be implemented across >60% of global bulk shipping (vs ~40%).
  • Generate cumulative annual fuel savings of approximately 5 to 7% of total global shipping fuel consumption (vs ~2 to 3% currently).
  • Possibly be subject to IMO regulatory mandate by 2027 to 2030.

The principal driver remains the rising cost of fuel under EU ETS Maritime, FuelEU Maritime and the IMO Net-Zero Framework GFI standard from 2027.

See also

References

  1. IMO MEPC. Resolution MEPC.323(74) - Invitation to Member States to encourage voluntary cooperation between the port and shipping sectors to contribute to reducing GHG emissions from ships. IMO, 17 May 2019.
  2. IMO. GloMEEP JIT Arrival Study. IMO Marine Environment Division, 2018.
  3. BIMCO. BIMCO Just-In-Time Arrival Clause for Time Charters. BIMCO, Copenhagen, October 2020.
  4. Port of Rotterdam Authority. Pronto Annual Report 2024. Rotterdam, 2024.
  5. PortXchange. Annual JIT Implementation Report 2024. PortXchange, Rotterdam, 2024.
  6. Maritime and Port Authority of Singapore. Maritime Singapore Connect Annual Report 2024. MPA, Singapore, 2024.
  7. C40 Cities. Green Ports Forum: Port Digitalisation Status Report. C40, London, 2024.
  8. ITF / OECD. Maritime Decarbonisation: Reduce, Restructure, Replace - JIT Section. International Transport Forum, Paris, 2024.
  9. Inchcape Shipping Services. Optic Platform Annual Report. Inchcape, London, 2024.
  10. Veson Nautical. Just-In-Time Arrival in Charter Party Operations. Veson, Boston, 2023.
  11. DNV. Maritime Forecast to 2050 - JIT Arrival Section. DNV, Oslo, 2025 edition.
  12. Lloyd’s Register. Just-In-Time Arrival: Practical Implementation Guide. Lloyd’s Register Marine, London, 2024.
  13. UNCTAD. Review of Maritime Transport 2024 - Port Operations Section. United Nations Conference on Trade and Development, Geneva, 2024.

Further reading

  • IMO. MEPC.1/Circ.884 on Industry Cooperation for JIT Arrival. IMO, 2020.
  • DNV. Maritime Forecast to 2050. DNV, Oslo, 2025 edition.
  • Hapag-Lloyd. JIT Arrival Operational Manual. Hapag-Lloyd, Hamburg, 2024.