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Live From Nor-Shipping 2019

80% of scrubbers are open-loop: DNV GL

The vast majority of over 3,000 scrubber installations to ships are for open-loop systems despite concerns over washwater, with some countries banning use in their waters, according to classification society DNV GL.

Fabian Kock, head of certification for DNV GL told a webinar on Thursday, that over 3,000 ships, both newbuilds and existing would have scrubbers fitted, or already had systems installed, to comply with the IMO 2020 sulphur cap.

The total number of scrubbers systems ordered or installed has risen to 3,266 at present from 1,850 in October 2018.

Read more: Scrubber numbers surge to 1,850 - 'decision to invest should be made yesterday'

Despite the controversy over washwater from open loop scrubbers such systems form the majority ordered by shipowners. According to DNV GL some 2,625 out 3,266 scrubbers systems being installed, or 80.3%, are of the open-loop variety. Hybrid systems account for 540 scrubber installations, 65 closed-loop and for 36 systems it was unclear what type was being fitted.


At present open-loop scrubbers are either banned, or will be come 1 January 2020 from the waters of Singapore, Fujairah, China – ports and inland waters, Belgium, Germany, Latvia, Lithuania, Ireland, Norwegian heritage fjords, and possibly India. In the US California bans scrubber use unless the owner has an exemption, and Connecticut bans washwater discharge.

The bans in Singapore and China are significant given the large proportion of installations on containerships and bulkers. In terms of segment distribution bulk carriers for the largest number with 1,129 installations, containerships with 588, oil/chemical tankers with 470, crude oil tankers at 414, and 265 cruise ships, with a variety of vessel types making up the remainder.


In terms of when the installations are taking place Kock said that the “scrubber wave” was now on with 2,083 systems being fitted in 2019, or an average 5.8 scrubber conversions per day. The majority of the installations are retrofits on existing ships accounting for 1,679, while 404 systems are being fitted to newbuildings. The peak for installations is set to take place in June/July this year as owners look to have scrubbers fitted in time for the sulphur cap coming into force on 1 January 2020.