MEPC.337 container-ship reference line.
Formula
$$ \text{CII}_\text{required} = 1984 \cdot \text{DWT}^{-0.489} \cdot (1 - Z) $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $DWT$ | Deadweight | t | tonnage certificate |
| $Z$ | Annual reduction | fraction | MEPC.338(76) |
Container d-boundaries: d1=0.83, d2=0.94, d3=1.07, d4=1.19. Lower $c$ exponent (0.489) compared to bulkers/tankers: required CII drops more slowly with capacity, so larger ships don’t get a disproportionate rating advantage.
Sources
- IMO MEPC.337/338/339(76).
- World Shipping Council - container ship emissions factsheet.