Surveillance of Sulfur Fuel Content in Ships at the Great Belt Bridge 2020
Report, 2021

Results are reported from stack gas emission measurements of individual ships at the Great Belt Bridge in Denmark. From the data the fuel sulfur content (FSC) used by the ships has been estimated. The project has been carried out on behalf of the Danish Environmental Pro-tection Agency and this report covers the period December 2019 to November 9, 2020. The overall aim of the project was to carry out operational surveillance of ships with respect to the EU sulfur directive that was entered into force in 2015 and which is implemented in the Danish legislation. It requires the usage of low sulfur marine fuel in SECAs (0.10 %) or using abate-ment technique (e.g. scrubber), The main purpose of the surveillance was to guide further port state control of ships at the destination harbors of the ships, both in Denmark and other ports, and to gather general statistics about compliance rates.
This report describes the technical systems and their performance and discusses the general compliance levels with respect to the EU sulfur directive and Danish legislation. The surveil-lance measurements were conducted by automatic gas sniffer measurements at the Great Belt Bridge, reporting in real time to a web database. The measurement systems have been developed by Chalmers University of Technology through Swedish national funding and EU projects. The measurement system at the Great Belt Bridge has been in operation since 2015.
In the period December 2019 to November 9, 2020, 3910 valid sniffer measurements of indi-vidual ships were carried out at the Great Belt Bridge with medium and good quality. The pre-cision of the fixed sniffer is estimated as 0.04 FSC % (1σ) and therefore only ships running with an FSC of 0.18 % (2σ) or higher can be detected as non-compliant ships with reasonable statistical confidence. The sniffer also has an estimated systematic bias of - 0.077 % FSC for the measurements in 2020, based on comparisons with port state control authorities. This bias, together with the measurement precision, is accounted for when determining the non-compliance threshold value. The data for the period December 2019 to November 9, 2020 shows a compliance rate of 98.6 %. This corresponds to 55 non-compliant ships (1.4 %) and out of these only 1 ship (i.e. 0.03 %) was in gross non-compliance, i.e. running with FSC above 0.3 % while the rest had an FSC below 0.14 %. This is slightly lower than in 2019 (4 ships corresponding to 0.075% above FSC 0.3 %) and it can be compared to the correspond-ing numbers for 2018 when the compliance rate was 95.3 % and 1.8 % of the ships were in gross noncompliance. One reason for the improvements could be that scrubber installations appears to work better in 2019 and 2020 compared to the previous years.
The observed high and improved compliance rate in 2020 is similar to the measurements in 2019 and consistent with other measurement studies in northern Europe during 2019. Airborne mini-sniffer measurements of 600 ships around the coast of Denmark, on behalf of the Danish EPA, shows 50 % less noncompliance between 2018 and 2019, with only 3 ships above FSC of 0.3 %. Sniffer measurements carried out in Belgian waters, in the English Channel, by fixed wing aircraft show that the non-compliance rates of ships with FSC above 0.4% changed from 4.9 % to 0.4 % between 2018 and 2019, with similar values in 2020. Fixed site measurements in the ship channel to Hamburg shows improved compliance rates since 2015 with noncompli-ance rates less than 1 % in Wedel and Bremerhaven in 2019. Sniffer measurements at the Öresund Bridge by Chalmers University of Technology, on behalf of Swedish transport agency, shows 99.7% compliance rates in 2020 with no ships in gross noncompliance.


Johan Mellqvist

Chalmers, Space, Earth and Environment, Microwave and Optical Remote Sensing

Alexander Vladimir Conde Jacobo

Chalmers, Space, Earth and Environment, Microwave and Optical Remote Sensing

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Geotechnical Engineering

Earth and Related Environmental Sciences

Marine Engineering




The Danish Environmental Protection Agency

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