NOx Tier III standards are in effect in ECAs from January 1st 2016. These limits apply to the North American and US Caribbean ECAs from 1 January 2016. However, MEPC 71 decided that from 1 January 2021, they will also apply to the Baltic Sea and the North Sea.

Accordingly, to make sure that the vessel is in compliance with the IMO Tier III standard, the engine's exhaust fumes are subjected to a special after-treatment known as Selective Catalytic Reduction (SCR).

Boluda commented that Boluda Towage Europe is the first company in the EU to convert an existing tugboat, complying with the IMO Tier III standards. The company conducted the project along with supplier Anglo Belgian Corporation with the aim of reducing shipping emissions and addressing local port authorities’ demand for cleaner operations in the port area.

Gert Van Den Steene, Manager Aftersales Department of Anglo Belgian Corporation stated that

The project posed quite a challenge – in that we needed to set up and install a complete SCR system on board an existing tug with a complex engine room, while retaining the tug’s operational and practical functions.

The decision to select Union Koala was based on the available space in the tugboat’s engine room for installing the SCR system. In addition, Union Koala is still in service in Zeebrugge’s port area: the Zeebrugge port authorities attach strong importance to sustainability and promote reducing vessels’ environmental footprint.