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Pre-swirl duct retrofit

vendor claim — not yet independently measured

A duct mounted ahead of the propeller that conditions the water flow into it, improving propulsive efficiency on full-form hulls. Benefit depends on the hull's wake field and falls away on fast, fine-form ships.

3–8%
CO₂ emissions reduction
€150k–450k
indicative capex band (vendor/literature prior)
2–5 days
drydock required
10,029
candidate vessels (fitment unverified — equipment data cannot prove absence)

Which ships it suits

  • Segments: Bulk carrier, Oil tanker, Chemical tanker, General cargo ship, Combination carrier
  • Size: from 10,000 DWT
  • Remaining service life: at least 5 years (payback must fit inside it)
  • Engine: two-stroke main engines only
  • Service speed: up to ~16 kn — the device underdelivers on faster, finer hulls

Candidate vessels — worst CII band first

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Measured real-world outcomes

The reduction range above is a vendor claim. We continuously detect completed retrofits in shipyard-visit, equipment and EU MRV emissions data and measure the actual AER change. Measured results are published per measure once at least 30 controlled observations exist — until then, treat vendor ranges as ceilings: real-world delivery is consistently at or below the low end.