Call us on +44 (0) 1983 282834 or reach out via our contact form.

We have developed a shaft power limitation (SHaPoLi) EEXI Shaft Power System, providing the necessary features and functionality to comply with the MARPOL Annex VI, MEPC.335(76) EEXI regulations.

Our system uses a Shaft Power Acquisition Module to constantly display, monitor and record propulsion shaft power to ensure compliance with the EEDI requirements relating to CO2 emissions for ships over 400 gross tonnage. 

LR Type Approval Button


Key Features

Key Features

EEXI SHaPoLi – Shaft Power Acquisition Module Explained

Voyage reports are automatically produced in support of the regulatory port authority documentation requirements, providing the most convenient way to evidence EEXI compliance.

In exceptional circumstances where the Ship’s Master or Office in Charge need to override the EEXI power limiter (for events such as Adverse Weather, Ice-Infected Waters, Rescue Operations, Avoidance of Pirates and Engine Maintenance), Datum’s EEXI Shaft Power Acquisition Module logs the exact time and reason for the power exceedance.

How EEXI works

How it works

Datums EEXI Shaft Power Acquisition Module continuously monitors, records and displays the instantaneous power being developed at the propulsion shaft when the vessels engine shaft is connected to Datums Shaft Power Meter.

The Software

The EEXI SHaPoLi Interface module incorporates highly encrypted software to support the regulatory needs for authenticated data. A point-to-point secure serial data link from the EEXI SPM Control unit to the bridge located EEXI Interface, provides uninterrupted data string, containing high accuracy torque, shaft rpm and power.

Live reporting

The EEXI SHaPoLi Interface module is a high-performance industrial panel mounted computer, allowing for the secure storage of the following critical logfile datasets:

Datum EEXI Brochure 4pp A4 2022 v4.1 1

The EEXI SHaPoLi Interface module provides the ships Master or OICNW with the live and instantaneous Shaft Power being produced by the vessel, and represented relative to the Power Reserve threshold, as determined by vessel type and size.


Download the brochure here

Enquire / Buy

Reach Out Today

Call us on +44 (0) 1983 282834.

Simply enter your details below and click on the Submit button. Our team will contact you shortly.


Ensure compliance with EEXI requirements.

A standardised and cost-effective solution.

Non-intrusive and quick retrospective installation.

Integrate with Existing Datum Shaft Power Meters and Datum Hawk systems.

Does not limit operational flexibility for vessels with multiple shaft lines or multiple engines per shaft.

Fast solution delivery to assist you in meeting your ESG and socio-economic goals, reducing carbon footprint.

System/ Vessel Integration

EEXI SHaPoLi Interface – The Process

The Datum EEXI SHaPoLi system seamlessly integrates to existing vessel hardware and electronics infrastructure.

The EEXI Shaft Power Meter can be installed (by an approved Service Engineer) in less than two days and requires no more than 320mm of available shaft section (typically the intermediate shaft).

The EEXI Interface, by regulation is to be installed in the bridge, and can be installed in no more than one day (when not being installed at the same time as the EEXI SPM).

Note: In order to satisfy the regulation, the ship must make a GPS data source (NMEA protocol) available at the location of the EEXI Interface installation. This is to allow the syncing of UTC date/time and the required vessel location coordinates during the Power Reserve breaches (and when returning to the limited power use).


Dashboard Overview


BreachAlarmAt the point of any Power Reserve threshold breach, the EEXI Interface main screen will provide a visual and audible alarm, highlighting to the ships Master or OICNW that the vessels Power Reserve has been breached.


Sample Breach Record


Power reserve breach record: The Datum SHaPoLi EEXI Interface not only continuously records all Shaft Power data, but also creates a Power Reserve Breach Event Record whenever the Shaft Power exceeds the Power Reserve threshold.


Justification Notes


Every Power Reserve Breach Event requires the ships Master or OICNW to justify the reasons for the use of Power Reserve, as per regulation 3.1 of MARPOL Annex VI (e.g. operating in adverse weather and ice-infested waters, participation in search and rescue operations, avoidance of pirates and engine maintenance).


Compliance Reporting


Data recorded in accordance to regulation: In case of having used the Power Reserve, the ship should without delay notify its Administration or RO responsible for issuing the relevant certificate and the competent authority of the relevant port of destination with the information recorded in accordance with MEPC.335(76), paragraph 3.2.




Datum’s EEXI SHaPoLi reporting comprehensively supports the EEXI regulation. Our compliance reports offer complete flexibility on report views (daily, weekly, monthly, annually) to suit your requirement. This is helpful for reporting uses of power reserve to meet IMO legislative requirements.





      • What is EEXI?
        Datum Electronics EEXI SHaPoLi solution – example screenshot of interface
        The Energy Efficiency eXisting ship Index (EEXI) is a new IMO regulation that aims to reduce CO2 emissions of existing vessels by setting minimum requirements for technical efficiency. EEXI comes into force on 1 January 2023. Datum Electronics, a world leader in smart sensor technology, has developed a Shaft Power Limitation (SHaPoLi) EEXI system providing the necessary features and functionality to comply with the MARPOL Annex VI, MEPS.335(76) regulations.
      • When will the EEXI enter into force?
        Datum Electronics’ EEXI SHaPoLi solution for compliance with MARPOL Annex VI

        The amendments to MARPOL Annex VI are expected to enter into force on 1 November 2022, with the requirements for EEXI and CII certification coming into effect from 1 January 2023. This means that the first annual reporting will be completed in 2023, with the first rating given in 2024. - Source

        Datum Electronics, a world leader in smart sensor technology, has developed a Shaft Power Limitation (SHaPoLi) EEXI system providing the necessary features and functionality to comply with the MARPOL Annex VI, MEPS.335(76) regulations.

      • What will be the improvement measures for my vessel?
        Datum’s EEXI SHaPoLi interface screenshot reporting breach events

        Different improvement measures are possible, e.g. Engine power limitation, Shaft power limitation, Engine derating, Propulsion optimization, Energy-saving devices, Please get in contact with DNV's maritime advisory for a ship-specific evaluation.

        To discuss a suitable hardware/software solution, feel free to contact the product specialists at Datum Electronics, developers of market-leading SHaPoLi EEXI solutions. 

      • Do I have a time frame for being compliant? Such as the next annual survey?
        Datum’s EEXI SHaPoLi software compliance report example screenshot

        The EEXI Technical File must be approved and the International Energy Efficiency Certificate re-issued by your flag administration or Recognized Organization at the first annual survey after 1 January 2023 at the latest.

      • Which vessels does the EEXI apply to?
        How it works - Datum’s EEXI SHaPoLi solution overview diagram

        The EEXI must be calculated for all cargo and cruise vessels above 400 GT falling under MARPOL Annex VI. In case of non-conventional propulsion (such as diesel-electric), please see MARPOL Annex VI for further clarification. In case of a major conversion, the EEXI must be recalculated. A required EEXI is applicable for all cargo and cruise vessels above a certain size threshold, depending on the ship type.

        Datum Electronics’ SHaPoLi Shaft Power Acquisition Module (SPM) is suitable for all vessel types and sizes, requiring access to no more than 320mm of shaft section.  Seamless integration with our EEXI interface software installed in the bridge means that the entire system can be installed and running within two days.

      • Will EEXI requirements change in the near future?
        Introducing Datum’s EEXI SHaPoLi solution – bridge dashboard screenshot

        A review clause requires the IMO to review the effectiveness of the implementation of the CII and EEXI requirements, by 1 January 2026 at the latest, and, if necessary, develop and adopt further amendments. - Source

        Datum Electronics is a market-leading SHaPoLi EEXI solutions provider, offering both hardware and software solutions for vessels of all types and sizes

      • Can I use any class to approve/verify the EEXI or do I need to use the vessel’s class?
        The approval of the EEXI Technical File and the issuance of the IEEC has to be performed by the respective classification society.
      • What is the required EEXI which my vessels have to fulfil?
        The required EEXI is based on the EEDI reference lines, with the below listed reduction factors applied. This is in most cases equal to the required EEDI in Phase 2 or Phase 3.
      • What documents are to be submitted for class approval?
        You need to submit an EEXI Technical File to your classification society. DNV's maritime advisory offers support by preparing such documents for you.
      • Will this approval have an impact on statutory certificates?
        Yes, after approval of the EEXI Technical File by the ship’s classification society, the IEE Certificate will be re-issued
      • What is the timeline for the re-issuance of the IEE Certificate?
        The IEE Certificate is re-issued with the first annual survey after 1 January 2023.
      • Is an EPL the only way to improve the EEXI?
        No – Shaft power limitation, Propulsion optimization and Energy-saving can be realised with the installation of Datum Electronics Shaft Power Meter and EEXI Control Panel Interface (Bridge mounted)
      • Are there certain rules or requirements by flag states or class when limiting the engine?
        Classification societies may have certain rules in place for engine limitation (e.g. if Ice class is applicable to your vessel). Please check with your respective classification society individually.
      • What about Ice-classed vessels which have certain requirements regarding minimum speed in ice?
        All requirements regarding the applicable Ice class have to be considered. If it is not possible to fulfil both, Ice class and EEXI requirements, additional measures have to be considered.
      • How about engines which are already derated? Can this engine be limited to an even lower level?
        You could further limit your engine output, for instance for a second time, if necessary to fulfil the requirements by installing Datum Electronics Shaft Power Meter and EEXI Control Panel Interface. Unlike rigid engine limiters, Datum’s EEXI system allows the vessel Master to retain full control of the engine output (for instances where safety is paramount, as defined by SOLAS), whilst still providing the essential data to support the regulatory needs.
      • Would an installation of a diesel-electric engine exempt my vessel from EEXI?
        Yes, except if it is an LNG carrier or cruise passenger ship.
      • What kind of document/proof is required after the EPL has been carried out?
        The following documents should be submitted: EPL Report (by engine manufacturer) Survey statement by class surveyor after EPL installation, EPL Management Plan
      • May EPL lead to other operational issues such as increased vibration?
        Yes. In most cases, limiting the power range goes along with a limitation of the operational revolution range. The new operational revolution rate may cause resonance conditions, resulting in increased structural or machinery vibrations. Higher vibration levels may lead to crew discomfort, structural damages and machinery failure. If power limitation is realized by deactivating cylinders, this will completely change the engine’s dynamics, requiring a new assessment of shaft torsional vibrations and of shipboard vibration due to changed firing frequency, as well as of modified excitation forces and moments. Please contact us again to assess the specific risk for your vessel.
      • What is required to verify the performance improvement of an ESD?
        It is recommended to carry out a model test to predict the performance improvement of the ESD before installation. This model test result will then be used for the calculation of the attained EEXI. The decision about the installation of an ESD should be based on a model test or CFD prediction.

      STEP Drawings

      Enquire Now

      Please fill out the below form and a member of our team will contact you shortly.