🛳️ Sea transport

Best practices

1. Provide weight:
   • Defining the total weight of the shipment refines emissions intensity (e.g., kg CO₂e per ton-km).
   • However, for sea transport, total emissions are based on the vessel's energy usage and allocated by container capacity, meaning total emissions are impacted by the number of TEUs, not directly by the weight.
2. Use containerSizeTypeCode for FCL and LCL shipments:
   • Specify the size and type of containers to compute the correct number of TEUs.
   • If no weight is provided, an average weight of 10 tons per TEU is used.
   • If no containerSizeTypeCode is provided, the default is 20GP (equivalent to 1 TEU).
3. Provide vessel.imo or vessel.name:
   • Vessel parameter tie emissions to specific vessels, incorporating precise characteristics (e.g. capacity, engines, auxiliary engines, boilers) into the calculations.
   • When both are provided, priority is given to the vessel.imo.
4. Include detail.departure.date:
   • Use this parameter to enable historical emissions calculations. Calculations are based on rebuilt voyages derived from real historical AIS data, ensuring accuracy even for multi-stop journeys with inferred connections. This reconstruction considers:
     • Specific vessel voyages (if vessel.imo or vessel.name is passed)
     • Carrier services and fleet (if scac is passed)
     • General industry patterns when neither vessel nor carrier is specified
       By combining historical trajectories, routing constraints, and connections between vessels, the system provides emissions calculations based on actual port calls and vessel activity for the given departure date.
5. Add carrier.scac (carrier code):
   • When vessel information is incomplete or unavailable, the scac information serves as a fallback, enabling the system to calculate emissions based on the carrier's fleet and services.
6. Specify fuelType:
   • Simulate emissions using greener fuels to reflect sustainable initiatives, offering enhanced accuracy for emissions savings scenarios.
   • This parameters is not compatible with the application of a detail.departure.date nor a carrier.scac.

Colliding parameters

1. weight vs. nContainers:

   • If both are provided:
     • weight: affects emissions intensity.
     • nContainers: determines the number of TEUs, applying an average weight of 10 tons per TEU for total emissions.

2. scac vs. vessel.imo:

   • imo prevails if both are provided.
   • If no IMO is found, the system falls back to the carrier's fleet and services using the carrier.scac.

Models used

• sfd-direct-emissionfactors: the default model, applied when only from and to are provided without additional details.
• sfd-direct-imo: used when a vesselImo or vesselName are provided, but no detail.departure.date.
• actual-portcalls-ais: generated when a detail.departure.date is provided. The model can incorporate vessel.imo, vessel.name or carrier.scac for greater accuracy.
• network-portcalls-schedules: used when a carrier.scac is provided, but no vesselImo nor detail.departure.date is specified. This model leverages the carrier's service schedules and fleet characteristics.

Side notes

• dateTime object:
  • Allows passing both departure and arrival dates, but the arrival date is for informational purposes only.
  • Only the details.date.departure is used for emissions calculations based on historical voyages.