Surveillance of Sulfur Fuel Content in Ships at the Great Belt Bridge 2019

Report, 2020

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 Protection Agency and the contract covers the period March 2018 to December 2018. The measurements reported here cover the period March to November 2018 and in addition we report measurements during January and February 2018, carried out as part of the EU project Envisum. The overall aim of the project was to carry out operational surveillance of ships with respect to the EU sulfur directive and particularly the sulfur limits for marine fuel in SECAs (0.10 %), which entered into force on January 1st 2015, as well as to guide further port state control of ships at the destination harbors of the ships, both in Denmark and other ports. The main objective of this report is to describe the technical systems and their performance, although a discussion about the general compliance levels with respect to the EU sulfur directive is provided as well. The surveillance 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.
In the period January 2018 to November 2018, 3580 valid sniffer measurements of individual ships were carried out at the Great Belt Bridge (medium and good quality). The precision of the fixed sniffer is estimated as ±0.04 FSC % (1σ) with an estimated systematic bias of - 0.074 % FSC for the measurements in 2018, based on comparisons with port state control authorities. Therefore, only ships running with an FSC of 0.18 % or higher can be detected as noncompliant ships with confidence limit of 95 % by the fixed sniffer system, when accounting for the bias. The data for the period January to November show a compliance rate of 95.3 %.
Here 1.1 % of the ships were in gross non-compliance with the EU sulfur directive with values above 0.5 %. Additional 0.8 % of the ships were measured in the FSC interval 0.3-0.5 % while the rest had values below 0.3%. There are differences over time, with the highest values in the summer. On several occasions we encountered one specific ship that was non-compliant with respect to the EU sulfur directive and which was equipped with a scrubber that was being commissioned.