Published 25 April 2026 · last updated 28 April 2026

Bulbous Bow Retrofits

Bulbous bow retrofits are the replacement of an existing bulbous bow with a new geometry optimised for an operating profile (speed and draught range) that differs from the one for which the original bulb was designed. The retrofit became widespread after 2010 when the post-2008 collapse in container ship and bulk carrier operating speeds left tens of thousands of vessels operating at speeds 3 to 6 knots below their design speed, with the original bulb tuned to the higher speed and producing wave interference (rather than wave cancellation) at the new lower speed. A modern bulbous bow retrofit typically delivers 4 to 8% main-engine fuel saving at the new operating speed and is one of the few hull-form modifications that can be undertaken at a routine drydocking without specialist yard capability. The measure has become a standard tool for EEXI compliance, CII rating improvement and SEEMP III operational planning, and is listed as an innovative energy-efficient technology under MARPOL Annex VI Regulation 21 with a corresponding EEDI/EEXI credit calculated under IMO Innovative Technology Guidelines (Resolution MEPC.244(66)). ShipCalculators.com hosts the principal computational tools: the bulbous bow retrofit savings calculator computes the expected fuel and emissions reduction; the EEXI Required calculator and EEXI Attained calculator implement the EEXI compliance check; the CII Attained calculator and CII Required calculator compute the CII rating change. A full listing is available in the calculator catalogue.

Contents

Background and history

The Inui revolution and the original design rationale

The modern bulbous bow was developed in the 1950s and 1960s by Japanese naval architect Takao Inui (Tokyo University), building on earlier theoretical work by David W. Taylor at the US Navy’s David Taylor Model Basin and by William Froude. The principle is that the forebody pressure wave generated by the bulb (a quasi-spherical or quasi-elliptical protrusion forward of and below the stem) is approximately 180 degrees out of phase with the stem pressure wave generated by the conventional bow; the two waves partially cancel through destructive interference, reducing the wave-making resistance ($R_W$) by 5 to 15% at the design speed. See hull form design and ship resistance and powering for the theoretical basis.

The bulb’s wave cancellation is most effective at a single combination of Froude number ($F_n = V / \sqrt{gL_{WL}}$) and draught (which together set the wave length of both pressure systems). For Froude numbers in the 0.20 to 0.30 range typical of large bulk carriers, tankers and pre-2008 container ships, the bulb is the dominant resistance-reduction technology. By 1980 essentially all newbuild merchant ships above approximately 5,000 DWT were fitted with a bulbous bow.

Bulb geometry families

The principal bulb geometry families are:

Inui-type bulb (also Type 1, Cylindrical): nearly cylindrical longitudinal section with a hemispherical leading edge; high wave-cancellation efficiency at the design point but rapid degradation off-design; typical of pre-1980 designs.
Taylor-type bulb (also Type 2, Elliptical): vertically elongated elliptical cross-section; broader off-design tolerance than Inui type; typical of large tankers and bulk carriers in the 1980s and 1990s.
Delta-type bulb (also Type 3, V-shaped): V-shaped or delta cross-section descending from the stem; designed for moderate-speed container ships and ferries; good ballast-condition performance.
Hogner-type bulb: pear-shaped (top heavy) cross-section; classical European geometry favoured for general cargo ships and small bulk carriers.
Modern hybrid bulbs: post-2010 CFD-optimised geometries that combine elements of several classical families; typically named by the optimising shipyard (e.g. Hyundai Heavy Industries Wide Bulb, DSME Forward-Sloped Bulb, Samsung Heavy Industries Mewis-style Bulb).

For a more exhaustive treatment of bow geometries see hull form design; for the related stern-end geometry see the hull lines plan discussion.

The post-2008 design-speed collapse

The 2008 financial crisis triggered a structural collapse in seaborne trade demand and a corresponding collapse in operating speeds. Average container ship operating speed fell from approximately 23 knots in 2008 to approximately 17 to 19 knots by 2012 and to approximately 16 to 18 knots by 2020; average bulk carrier speed fell from approximately 14 knots to approximately 11 to 12 knots over the same period. This phenomenon, known as slow steaming (see also slow steaming), was a deliberate response to fuel-cost economics: the cubic-power relationship between speed and resistance means that a 20% speed reduction yields approximately a 50% fuel reduction (after adjusting for time on voyage).

The unintended consequence of slow steaming was that almost all the existing bulbs in service were tuned to the design speed and were now operating 2 to 6 knots below it, in a regime where the bulb wave was no longer cancelling the stem wave but reinforcing it. Lloyd’s Register (2014) and DNV (2015) reported that approximately 60% of the world container fleet and approximately 35% of the world bulk fleet were operating in this off-design condition.

The retrofit market emerges (2010 to 2014)

The first large-scale bulbous bow retrofit programmes emerged in the early 2010s. A.P. Moller-Maersk undertook a fleet-wide bow retrofit programme on its E-class and S-class container vessels between 2012 and 2015, retrofitting bulbs originally designed for 25-knot operation with new bulbs optimised for 17 to 18 knot operation. Mediterranean Shipping Company undertook a similar programme between 2013 and 2017. CMA CGM, Hapag-Lloyd, NYK, MOL, K Line and several large bulk carrier operators followed. By 2018 approximately 200 large container ships and approximately 400 large bulkers and tankers had been retrofitted; by 2024 the cumulative count exceeded approximately 1,500 vessels.

Acceleration under EEXI (2023 onwards)

The introduction of the Energy Efficiency Existing Ship Index (EEXI) in 2023 created a regulatory driver for bulbous bow retrofits. Vessels that fail to meet the EEXI required value at first survey on or after 1 January 2023 must implement engine power limitation (EPL) or shaft power limitation (ShaPoLi), or alternatively install eligible innovative energy-efficient technologies. A bulbous bow retrofit qualifies as an eligible technology under MEPC.244(66) and provides an EEXI credit of typically 2 to 4 percentage points, often sufficient to bring a vessel into compliance without resorting to EPL.

The combination of EEXI compliance pressure, CII rating improvement, EU ETS cost avoidance, FuelEU Maritime intensity reduction and the underlying fuel saving has made bulbous bow retrofits one of the most economically attractive energy-efficiency measures available in 2024.

Design and engineering

CFD-driven design process

The design of a retrofit bulb is a CFD-driven process typically undertaken in 8 to 16 weeks. The principal steps are:

Operational profile analysis: review of past 12 to 36 months of voyage data (speed, draught, weather) to characterise the future expected operating envelope. Typical inputs are AIS tracks, noon reports, EU MRV submissions and IMO DCS submissions.
Existing-bulb baseline CFD: full-scale CFD run on the as-built hull at multiple operating points (typically 5 draughts, 5 speeds) to establish the current resistance baseline. Validated against ship-trial data and in-service measurements.
Bulb geometry parametrisation: definition of the design space (typically 8 to 12 design variables: bulb length, bulb height, bulb width, bulb tip radius, bulb top profile, bulb side profile, bulb forward stagger, bulb tip droop, bulb top angle, bulb side angle).
Optimisation loop: typically an evolutionary algorithm (genetic algorithm or differential evolution) that explores the design space, with each candidate evaluated by full-scale CFD. Modern optimisation runs explore approximately 200 to 500 candidate geometries over 2 to 4 weeks of HPC time.
Final candidate validation: the optimum candidate is validated by additional CFD at the full operating envelope; for high-stakes retrofits a final model-test validation at MARIN, HSVA or SSPA may be undertaken.

The principal design houses for retrofit bulbs are: Hyundai Heavy Industries Marine Engineering (Korea), DSME R&D Center (Korea), Samsung Heavy Industries R&D (Korea), Mitsui MES Ship and Ocean R&D (Japan), Mitsubishi Heavy Industries Marine Engineering (Japan), Wartsila Ship Design (Finland), Vard Marine (Norway), Knud E. Hansen (Denmark), OSK ShipTech (Denmark), Houlder (UK), HSVA (Hamburg), MARIN (Wageningen), FORCE Technology (Lyngby) and several smaller specialised consultancies. See classification society for the related Class approval workflow.

Structural engineering

The retrofit bulb must be structurally compatible with the existing forward hull. The principal structural considerations are:

Plate thickness and grade: the retrofit bulb plating must match or exceed the existing forward shell plate thickness and steel grade (typically AH36 or DH36 for the forward shell, sometimes EH36 in ice-strengthened areas).
Stringer continuity: the longitudinal stringers and the deep web frames in the forepeak must continue uninterrupted into the new bulb structure.
Collision strength: the SOLAS Chapter II-1 collision-strength requirements (collision bulkhead location, plating thickness within the collision zone) must be respected by the new bulb.
Slamming reinforcement: the bulb forward face and underside must be reinforced for bottom slamming loads; the classification society Common Structural Rules (IACS CSR for bulk carriers and oil tankers) specify the relevant pressure heads.
Fatigue: the connection between the new bulb plating and the existing forward shell is a fatigue-sensitive welded joint; the design must satisfy IACS CSR fatigue criteria for the residual fatigue life.

The structural design is typically undertaken by the same design house as the hydrodynamic design, with Class approval typically taking 4 to 8 weeks. The principal classification societies for retrofit Class approval are DNV, Lloyd’s Register, ABS, BV, CCS, NK, KR and RINA.

Drydock execution

The drydock execution typically requires 14 to 28 days of additional drydock time over and above the routine special survey drydock period. The principal steps are:

Bulb removal: the existing bulb is cut off at a pre-defined cutting line (typically a transverse plane forward of the collision bulkhead) using underwater oxy-acetylene cutting or shore-based plasma cutting after the vessel is on blocks.
Forward shell preparation: the cutting edges are ground and prepared for the new welded joint.
New bulb fitting: the prefabricated new bulb (typically fabricated in 2 to 4 modular sections weighing 50 to 200 t each) is positioned by floating crane and aligned to the existing forward shell.
Welding: the new bulb is welded to the existing shell using qualified welding procedures, typically full-penetration butt welds with backing strips. Non-destructive testing (NDT) by ultrasonic, magnetic-particle and dye-penetrant methods is undertaken at all welded joints.
Surface preparation and coating: the new bulb plating is grit-blasted to SA2.5 surface preparation and coated with the same anti-fouling and anti-corrosive coating system as the existing hull. Major coating manufacturers (Hempel, Jotun, AkzoNobel International, Chugoku Marine Paints, Nippon Paint Marine) have specific retrofit-bulb coating specifications.
Sea trial validation: post-retrofit sea trials are undertaken to validate the predicted resistance reduction and to issue the updated EEDI/EEXI certificate.

The total cost of a retrofit (design, materials, drydock execution, Class approval, sea trials) is typically:

USD 400,000 to USD 800,000 for a Handysize bulker (35,000 DWT class)
USD 600,000 to USD 1,200,000 for a Panamax bulker (75,000 DWT class)
USD 1,000,000 to USD 2,500,000 for a Capesize bulker or VLCC (180,000 to 320,000 DWT class)
USD 1,500,000 to USD 4,000,000 for a Post-Panamax or Neo-Panamax container ship (8,000 to 14,000 TEU class)
USD 3,000,000 to USD 6,000,000 for an Ultra Large Container Ship (18,000 TEU+ class)

The Cosco Heavy Industries, CIMC Raffles, Drydocks World Dubai, Sembcorp Marine (now Seatrium), Keppel O&M (now Seatrium), Hyundai Mipo, HHI, DSME (now Hanwha Ocean) and Samsung Heavy Industries yards are among the most active in retrofit-bulb execution; specialist European yards (Damen Schelde, BLRT Grupp, Astican, Astilleros Canarios, Lloyd Werft, Blohm+Voss) also undertake the work.

Performance and economics

Typical fuel savings

Independent peer-reviewed and industry studies place the typical fuel saving from a bulbous bow retrofit in the range of 4 to 8% of main-engine fuel consumption at the new design speed. Specific findings include:

Hyundai Heavy Industries (2014): 4 to 6% on retrofit Capesize bulkers across a range of slow-steaming operating conditions.
MARIN (2015): 5 to 8% on retrofit container ships, with the higher end achieved on the largest (12,000+ TEU) post-Panamax hulls.
DNV (2018, EEXI study): 3 to 7% typical, with the higher end concentrated on hulls operating at 4+ knots below the original design speed.
A.P. Moller-Maersk (2017): 5 to 9% on the retrofit E-class container vessels, validated against shaft power measurements.
DNV Maritime Forecast to 2050 (2023): 4 to 8% typical.

The savings depend strongly on the mismatch between the original design speed and the current operating speed: the larger the mismatch, the greater the saving. For hulls operating within 1 knot of design speed, the retrofit benefit is typically negligible; for hulls operating 5+ knots below design speed, the benefit can exceed 10%.

Capital cost and payback

For a typical Post-Panamax container ship (8,500 TEU class) burning 80 t/d of VLSFO at USD 600/t, a 6% saving represents approximately 4.8 t/d, or USD 2,880/d, or approximately USD 880,000/y at 305 sea days. The payback period on a USD 2,500,000 retrofit is therefore approximately 2.8 years; on a USD 1,500,000 retrofit it is approximately 1.7 years. With EU ETS EUA costs and FuelEU Maritime penalty avoidance added, the payback typically improves by an additional 15 to 25%.

For a typical Capesize bulker burning 35 t/d of HFO at USD 600/t (slow-steaming condition), a 5% saving represents approximately 1.75 t/d, or USD 1,050/d, or approximately USD 320,000/y at 305 sea days. The payback period on a USD 1,500,000 retrofit is therefore approximately 4.7 years.

The bulbous bow retrofit savings calculator implements the full payback calculation.

CII improvement

The 4 to 8% fuel saving translates directly into a 4 to 8% reduction in Annual Efficiency Ratio (AER), which is the CII proxy under the IMO 2023 CII Guidelines. For a typical container ship or bulk carrier currently rated C under the CII rating, a bulbous bow retrofit is typically sufficient to upgrade the rating to B, avoiding the CII corrective action plan trigger that arises after three consecutive D ratings or one E rating.

EEXI compliance

For vessels currently failing the EEXI required value, a bulbous bow retrofit provides an Innovative Technology credit of typically 2 to 4 percentage points (calculated under MEPC.244(66) with reference to the model-test or CFD-validated savings). This is often sufficient to bring the vessel into EEXI compliance without resorting to Engine Power Limitation (EPL) or Shaft Power Limitation (ShaPoLi), preserving the option to operate at higher speeds in the future. See the EEXI Required calculator, EEXI Attained calculator and EPL Required MCR calculator for the EEXI compliance arithmetic.

Notable retrofit programmes

A.P. Moller-Maersk E-class bulb retrofit (2012 to 2015)

A.P. Moller-Maersk undertook one of the first and largest bulbous bow retrofit programmes between 2012 and 2015, replacing the bulbs on its 8 E-class container ships (Emma Maersk, Estelle Maersk, Eleonora Maersk, Evelyn Maersk, Ebba Maersk, Elly Maersk, Edith Maersk, Eugen Maersk; each 14,770 TEU) with bulbs optimised for the new 17 to 18 knot economic speed. The original bulbs were designed for 25 knots; the retrofit bulbs delivered approximately 8% main-engine fuel saving at 17 knots. The retrofit was undertaken by HHI at Ulsan, Korea, with design support from Hyundai Maritime Research Institute. Each retrofit cost approximately USD 4 million and took approximately 21 days drydock time.

MSC and CMA CGM container fleet retrofits (2013 to 2018)

Mediterranean Shipping Company (MSC) undertook bulbous bow retrofits on approximately 70 container ships between 2013 and 2018, principally on the 8,500 to 14,000 TEU class. CMA CGM undertook approximately 60 retrofits over the same period. Both programmes targeted vessels operating 4 to 6 knots below their original design speeds and reported fleet-wide fuel savings of approximately 5 to 7% on the retrofit vessels.

Hapag-Lloyd, NYK and MOL retrofits

Hapag-Lloyd (approximately 30 retrofits, 2014 to 2018), NYK (approximately 25 retrofits, 2013 to 2019, including 14 LNG carriers) and MOL (approximately 35 retrofits, 2014 to 2020) undertook similar programmes. NYK’s retrofits on the Sayaringo STaGE class (174,000 m3 LNG carriers) were notable for combining the bulb retrofit with a propeller redesign and a Mewis duct installation, achieving combined savings of approximately 12 to 15%.

Tanker fleet retrofits (2015 onwards)

The crude oil tanker fleet was slower to adopt bulbous bow retrofits because the time-charter market structure leaves the fuel saving with the charterer rather than the owner. The Frontline, Euronav (now CMB.TECH) and Teekay fleets undertook approximately 20 to 40 retrofits each between 2015 and 2022, principally on Suezmax and VLCC tonnage. Maran Tankers Management undertook approximately 30 retrofits over the same period.

EEXI-driven retrofits (2022 to 2024)

The introduction of EEXI in 2023 triggered a wave of retrofit work in 2022 to 2024. DNV estimated in 2024 that approximately 800 vessels worldwide had undertaken a bulbous bow retrofit specifically for EEXI compliance, in lieu of Engine Power Limitation or Shaft Power Limitation. DSME (now Hanwha Ocean), Samsung Heavy Industries and HHI captured approximately 60% of this retrofit market between them.

Versus EPL/ShaPoLi

Engine Power Limitation (EPL) and Shaft Power Limitation (ShaPoLi) are the alternative compliance mechanisms for vessels failing EEXI. EPL/ShaPoLi has lower upfront cost (typically USD 50,000 to USD 200,000 for the engine modification and Class approval) but permanently caps the vessel’s maximum speed at the limited power; the bulbous bow retrofit, by contrast, preserves the option to operate at higher speeds and delivers a continuing fuel saving regardless of operating speed. For owners who expect the vessel to operate predominantly at slow steaming for the remainder of its life, EPL/ShaPoLi is typically the preferred option; for owners who anticipate periodic speed increases (e.g. for charterer-driven schedule recovery), the bulbous bow retrofit is preferred.

Versus air lubrication

Air lubrication systems deliver typical 5 to 10% fuel savings, with a similar payback profile to bulbous bow retrofits but with significantly higher upfront cost (typically USD 1.5 to 4 million for an installation, depending on hull size). Air lubrication is more easily retrofitted at any time (no drydock needed for the air supply system installation, only for the underwater piping) and provides savings that are largely speed-independent.

Versus wind-assisted propulsion

Wind-assisted propulsion (rotor sails, wing sails, towing kites, soft sails) delivers typical 5 to 25% fuel savings, with strongly route-dependent performance. The combination of bulbous bow retrofit + wind-assisted propulsion is increasingly favoured for vessels on consistently windy routes (Trans-Atlantic, Trans-Pacific, North Sea, Baltic).

Versus energy-saving devices

Energy-saving devices (PBCF, Mewis duct, pre-swirl stator, rudder bulb) deliver typical 2 to 6% fuel savings, with much lower upfront cost (typically USD 100,000 to USD 500,000) and shorter installation time (typically 5 to 10 days during a routine drydock). The combination of bulbous bow retrofit + ESDs is the most common combined retrofit package, delivering combined savings of typically 8 to 14%.

Combination economics

The SEEMP Measures Combined calculator implements the combined-savings calculation, accounting for the diminishing-returns interaction between measures (each measure reduces the fuel basis on which subsequent measures are calculated).

Safety, stability and operational considerations

Trim and draught implications

A retrofit bulb is typically larger and heavier than the original bulb, shifting the longitudinal centre of gravity (LCG) and the longitudinal centre of buoyancy (LCB) of the vessel. The shift is small (typically less than 0.3 m forward) but must be accommodated in the loading computer and the trim and stability booklet. The new trim optimisation curves must be recalculated for the modified hull form.

Damage stability implications

The retrofit bulb adds buoyancy forward of the collision bulkhead, which can affect the post-damage trim and stability after a forward collision. The Class submission must include updated probabilistic damage stability calculations under SOLAS Chapter II-1 to demonstrate continued compliance.

Slamming and bow flare loading

The retrofit bulb experiences bottom slamming loads in head seas, particularly in ballast condition where the bulb is partly emerged. The Class approval process includes hydrodynamic load assessment (typically by CFD or empirical formulae from IACS CSR) to verify the structural design.

Cavitation interaction

A retrofit bulb modifies the wake field at the propeller plane, potentially altering the propeller cavitation behaviour. For high-power vessels (typically container ships and LNG carriers) the retrofit design must include CFD assessment of the wake field at the propeller plane to verify that no new cavitation problem is introduced. In some cases the bulb retrofit is combined with a propeller redesign to optimise the propulsion system as a whole.

Ice class considerations

For vessels with ice class notation (Polar Class, Finnish-Swedish Ice Class, Baltic Ice Class), the retrofit bulb must satisfy the additional ice-strengthening requirements (additional plate thickness in the ice belt, additional structural reinforcement, ice-knife geometry). Most retrofit programmes maintain or upgrade the existing ice class; in rare cases the retrofit may downgrade the ice class if the bulb geometry no longer meets the relevant criteria.

Bow thruster interaction

For vessels equipped with a bow thruster (most large container ships, ferries, cruise ships, some bulk carriers and tankers), the retrofit bulb must accommodate the existing bow thruster tunnel; in most cases the tunnel is preserved unchanged, but in some cases the tunnel must be moved or modified, adding cost and complexity to the retrofit.

Limitations and risks

Charter market structure

For vessels in the time-charter market, the fuel cost is borne by the charterer but the retrofit cost is borne by the owner; the owner therefore has limited direct financial incentive to invest in the retrofit. The BIMCO CII clauses, Sea Cargo Charter reporting framework and EUA pass-through clauses are gradually realigning the incentives, but the misalignment remains a structural impediment to retrofit uptake in the bulk carrier, chemical tanker and LNG carrier sectors.

Forecasting uncertainty

The retrofit design relies on a forecast of future operating speeds and draughts. If the actual future operating profile differs materially from the forecast (e.g. because fuel prices fall and operating speeds rise, or because the vessel is sold to a different operator with a different trade pattern), the retrofit may underdeliver. Modern retrofit designs typically aim for broad-band optimisation (good performance across a range of speeds and draughts) rather than point optimisation (best performance at a single design point) to mitigate this risk.

Residual hull life

The retrofit makes economic sense only if the residual hull life (typically 5 to 15 years from the retrofit date) is sufficient to amortise the capital cost. For vessels nearing end-of-life (typically 20+ years for bulk carriers and tankers, 25+ years for container ships), the retrofit is typically not economic.

Sea-trial validation uncertainty

Independent validation of the realised savings by sea trial is challenging because of the variable wind, wave, current and hull-fouling conditions that prevail during the trial. The ISO 19030 standards provide a normalisation framework, but the residual uncertainty in the realised saving is typically ± 1 to 2 percentage points; reliable validation requires multi-month before-and-after datasets and statistical regression.

Future outlook

Continued EEXI-driven uptake

The EEXI requirement applies at the first survey on or after 1 January 2023 for each vessel; for vessels with 5-year survey intervals, this means the cumulative EEXI compliance trigger continues to roll through the world fleet through to 2027. DNV projects that an additional 600 to 1,200 vessels will undertake bulbous bow retrofits over 2025 to 2027 in response to upcoming EEXI surveys.

Combination retrofits

The trend towards combination retrofits (bulbous bow + energy-saving devices + air lubrication + wind-assist) is expected to accelerate, as owners seek to maximise the EEXI credit and the CII rating uplift achievable in a single drydocking. Combined-package savings of 15 to 25% are achievable on suitable hulls.

IMO Net-Zero Framework GHG fuel intensity

The introduction of the IMO Net-Zero Framework GHG Fuel Intensity (GFI) standard from 2027 will create an additional pricing signal for fuel-saving retrofits: each tonne of fuel saved is one fewer tonne against which the GFI standard is applied, reducing the Tier 1 and Tier 2 remedial unit liability. Modelled GFI cost savings of USD 50 to USD 150 per tonne of fuel saved are expected by 2030.

CFD optimisation maturity

The maturity of CFD-driven bulb design has reached the point where retrofit designs routinely achieve within 1 percentage point of the maximum theoretical bulb improvement. Further improvements will likely come from machine-learning surrogate models that allow much larger design space exploration in the available CFD time budget.

References

IMO Resolution MEPC.244(66): 2014 Guidelines on the Method of Calculation of the Attained Energy Efficiency Design Index (EEDI) for New Ships, as amended by Resolution MEPC.281(70) and MEPC.322(74). International Maritime Organization, 2014.
IMO Resolution MEPC.328(76): 2021 Revised MARPOL Annex VI. International Maritime Organization, 2021.
IMO Resolution MEPC.333(76): 2021 Guidelines on the Method of Calculation of the Attained Energy Efficiency Existing Ship Index (EEXI). International Maritime Organization, 2021.
IACS. Common Structural Rules for Bulk Carriers and Oil Tankers (CSR BC and OT). International Association of Classification Societies, 2024 edition.
ISO 19030-1:2016, ISO 19030-2:2016, ISO 19030-3:2016: Ships and marine technology, Measurement of changes in hull and propeller performance. International Organization for Standardization.
DNV. EEXI: Frequently Asked Questions. DNV Maritime, 2022.
DNV. Maritime Forecast to 2050. DNV Energy Transition Outlook, 2023.
Hyundai Heavy Industries. Bow Retrofit Programme: Technical Summary. HHI Marine Engineering, 2014.
A.P. Moller-Maersk. Sustainability Report 2017. Maersk Group, 2018.
Lloyd’s Register. Slow Steaming and the Bulbous Bow. LR Technical Briefing, 2014.
ICS. Catalysing the Fourth Propulsion Revolution. International Chamber of Shipping, 2022.