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Retrofit and certification

Amendment or new Technical File for retrofit projects, with measurements onboard or at your test bed. From the first talk with class to the approved file.

How we workTechnical FileMEPC.398(83) and Tier changesParent and member enginesOnboard and test bedInstallation supportProjects

Plan it from day one

Certification belongs in the project from the start

A retrofit is not finished until it is approved. Certification is easy to forget while the engineering and the installation take the attention, and it is expensive to fix at the end.

Bring it in from the first day, and the whole process flows: design choices, installation, tests and documentation fit together, and the vessel can return to service on time.

The same retrofit project, shown two ways.

The same retrofit project, with and without certification built in from the start Two project charts with the same phases: design, installation, tests and documentation. When certification is added at the end, a wrong assumption in design is found late, the test is not approved, and the project needs a redesign and a retest, so the vessel returns to service later. When legislation and class are part of the project from day one, design is checked early, the test is planned with class and the vessel can return to service on schedule. Certification added at the end Back in service, later Legislation and classDesignInstallationTestsDocumentation Class involved late Design ! Wrong assumption, found late Redesign↻ Installation Tests Not approved Retest Documentation Certification thought in from the start Back in service, on time Legislation and classDesignInstallationTestsDocumentation Rules and class shape every step, from first talk to approval Design Installation Tests Documentation Checked early Planned with class
Added at the end
  • !Design assumptions found wrong late
  • ×Test not approved
  • ↻Redesign, retest and a later return to service
Thought in from the start
  • ✓Design checked against the rules early
  • ✓Test planned with class
  • ✓Vessel back in service on time

See how we work, step by step

Retrofit and certification

How we work, from first talk to approved file

Six steps from first talk to approved file. We plan, measure and document, and we follow the file until class has signed, so you can focus on the conversion.

  1. 1

    First talk with class

    We agree scope and requirements with your classification society before anything is planned.

    ResultScope agreed with class
  2. 2

    Pre-supportive document

    A project description and a test plan with the measurement points, load points and any deviation from the test cycle, agreed through class before the test is scheduled.

    ResultTest plan and measurement points agreed
  3. 3

    Preparation

    We prepare the vessel and the test setup, and calibrate all equipment to NTC 2008.

    ResultSetup ready, equipment calibrated
  4. 4

    Optimisation

    If the engine needs tuning

    Together with your engineers, we evaluate which measures suit your engine and operation, measure before and after, and set the engine up for fuel efficiency within the emission limits.

    ResultEngine set up before the test
  5. 5

    Approval test

    Measured onboard or at your test bed, witnessed by the class surveyor. We calculate the NOx and cycle values.

    ResultMeasured and witnessed values
  6. 6

    Approved file

    Witness report, calibration sheets, emission calculations and the amendment or Technical File, fully documented. We follow it until class has signed.

    ResultSigned by class

Amendment and Technical File

Your engine changed. We get the Technical File approved.

Every retrofit that changes NOx-relevant components or settings needs an amendment to the Technical File, or a new one. We take it from the first talk with class to the last signature.

Faster, limited scope

Amendment

When a modified engine is already in an approved Technical File.

Scope of work
  • The modification and its NOx effect described
  • Simplified measurement method of NTC 2008
  • Targeted tests at the load points that matter
  • All equipment calibrated, results calculated against the approved file
  • The rest of the approved file stays in force
See examplesThe world’s first VCR retrofitTurbocharger matching and new timing
A larger piece of work

New Technical File

When the engine falls outside an existing file, for example a new engine group or a change of Tier.

Scope of work
  • The whole engine described, with its NOx-relevant components and settings
  • Full NTC 2008 Appendix V measurement on the parent engine
  • All emission and ambient equipment calibrated and documented
  • NOx and cycle values calculated for every test point
  • Complete test report, Technical File and Survey Document
  • Approved by class as a complete document
See exampleTier I to Tier III with SCR

In both cases we

  • Pre-supportive document

    Project description and test plan agreed with class before the first measurement.

  • Test where the engine runs

    Onboard or at your test bed, by our technicians, calibrated to NTC 2008.

  • Calculate the values

    NOx and cycle values, with every calculation documented.

  • Document for survey

    Reports and files ready for the surveyor.

  • Follow it to approval

    Until the last document is signed.

Talk to us before the scope is fixed

Retrofit and certification

Substantial modifications and Tier changes

MEPC.398(83): the route for certifying a modified engine, in force since 1 September 2026.

A substantial modification only holds up if the emissions can be proven. When the measurement and certification scope is brought in from the start, the outcome is known before the vessel returns to service, not discovered at survey. Compliance is built in from day one, with class aligned before the measurement, so the test is done once and the documentation stands up at survey.

MEPC.398(83) amends NTC 2008 with a defined route for an installed engine that has been subject to a substantial modification, or is to be certified to a Tier it did not hold at installation, for example with Tier III SCR. A Tier change means a new Technical File. The limits are unchanged, and the test is performed onboard.

Modifications that can affect NOx, such as LNG dual-fuel or methanol conversion, Tier III SCR, a fixed or variable compression ratio, turbocharger cut-out or part-load tuning, may count as a substantial modification. We assess it with you and class, and plan the test so it is done once.

    Substantial modification

    The route for installed engines that are substantially modified, or certified to a Tier they did not hold at installation.

    Parent engine tested onboard

    The procedure applies to the installed engine, so the parent engine is tested where it runs, onboard the ship.

    One engine group

    The modified parent engine represents the engine group. The other engines follow as member engines, with a parameter check instead of a full emission measurement.

    Clear test requirements

    The 100% load point may be as low as 85% of rated power if the test plan allows it. The test plan is agreed with the Administration before the test, and the nameplate is replaced if power or speed changes.

    See examplesMethanol conversionThe world’s first VCR retrofit
    Read moreA substantial modification only holds up if the emissions can be provenDownload as PDF (2 pages)

    Retrofit and certification

    Parent engine, member engines and engine groups

    Do the big work once. The more engines in the engine group, the more you save.

    The parent engine, normally the first engine in a series, carries the full job: full documentation, full procedures and the complete test programme. It is done once.

    Every other engine in the same engine group follows as a member engine, with a parameter check instead of a full measurement. The more engines in the group, the lower the cost per engine.

    Six different engines need six full programmes. Six identical engines can form one engine group, where only the parent engine needs the full programme.

    Effort for engines in one engine group, on their own and with a parent engineSix different engines each need a full programme. Six identical engines can form one engine group with a parent engine: only the parent needs the full programme and the other five need a parameter check, which saves effort and cost.Six different engines, each on its ownSix identical engines, one engine groupA full programme for every engineOne full programme, then parameter checksEffort and costEffort and costSavedEach engine on its ownParent engineFive member enginesEngine groupParameter checkSaved effort and cost

    Main engine and auxiliary engines

    The focus is often on the two-stroke main engine, where the potential looks largest at first sight. Auxiliary engines are often left untouched, because the fuel saving per engine is smaller. But a fleet often has many identical auxiliary engines that can share the same engine group. Certified once on the parent engine, the change is rolled out to every member engine with the parameter check method, and the small saving per engine becomes a large saving across the fleet.

    Your fleet

    We can go through your fleet for engines in the same engine group. Together we find where a parent engine can serve the most engines, and where the saving is largest.

    MEPC.398(83)

    MEPC.398(83) allows an individual engine or an engine group represented by its parent engine, but not an engine family. We build the parent file, define the parameter check and document how each member relates to the parent.

    See an exampleVIT conversion of auxiliary engines

    Retrofit and certification

    Onboard and test bed measurements

    Measured to NTC 2008 and ISO 8178, onboard or at your test bed.

    Every retrofit is proven by measurement. We measure onboard or at your test bed, to NTC 2008 and ISO 8178, with our own technicians and equipment calibrated to NTC 2008, and we document the result the way class and the authorities expect.

      ME-Tech measuring equipment set up beside the funnel, with sampling lines into the funnelOnboard | Measuring in the funnel

      NOx, CO, CO2, O2 and THC

      Measured with the analyzers the NOx Technical Code 2008 describes.

      Methane slip and N2O

      Heated FID with a non-methane cutter, and FTIR, following MEPC.414(84).

      Particulate matter and smoke

      Particulate matter measured gravimetrically, and smoke as filter smoke number.

      Onboard or at your test bed

      The equipment is packed for transport and can be used wherever the engine is.

      Read moreStandard emission measurements

      Retrofit and certification

      Technical support for installation

      Qualified technicians for your retrofit, from installation to the approval test.

      A retrofit is only finished when it is approved. Our qualified technicians carry out or assist the installation, and stay with the engine through the R&D test until it is ready for certification.

      Installation

      We carry out or assist the installation of your retrofit, working alongside the engine designer, the yard or the crew.

      • Installation carried out or assisted
      • Two-stroke and four-stroke engines
      • Planned together with the test schedule
      ME-Tech technician adjusting the engine onboardInstallation support | Adjusting the engine

      Adjustment during the R&D test

      During the R&D test we adjust and correct the engine on the spot, based on the measured results, so it is set up right before the final certification test.

      • Adjustments made from the measured results
      • No waiting for another team
      • Engine ready before the certification test

      What you get

      One team that installs, measures and adjusts, so the retrofit moves from installation to approval without loose ends.

      • Fewer days onboard
      • No second trip to the ship
      • Retrofit ready for the approval test on time

      Retrofit and certification

      Selected projects

      Typical work, shown without names.

      The world’s first VCR retrofit, tested and approved

      A two-stroke dual-fuel engine retrofitted with variable compression ratio, measured onboard and approved by amendment.

      Read the case

      Methanol conversion of a two-stroke engine

      Tier II and Tier III with SCR in diesel mode, and methanol added in both Tiers.

      Read the case

      Turbocharger matching and new timing on a Tier I engine

      Four-stroke Tier I engines, optimised with new turbocharger matching and timing.

      Read the case

      Tier I to Tier III with SCR for a research vessel

      Tier change from Tier I to Tier III with SCR, certified to Scheme B.

      Read the case

      VIT conversion of auxiliary engines

      Tier I auxiliary engines converted to variable injection timing, and certified.

      Read the case

      Turbocharger cut-out on a two-stroke engine, documented for EPA

      Turbocharger cut-out on a two-stroke engine in service, measured onboard and documented for EPA.

      Read the case

      Part-load optimisation of ferry auxiliary engines

      Four-stroke Tier I engines optimised for part-load fuel consumption.

      Read the case

      Planning a retrofit?

      Bring certification in from day one. Tell us about the engine and the modification.

      Contact us