Since September 2017, when the BWM Convention entered into force:

  • New ships must meet the D-2 standard.
  • Ships must be retrofitted and have a BWM Certificate by the first IOPP approval after 8 September 2019.
  • IMO has granted Basic approval to 58 systems.
  • IMO has granted Final Approval (for systems using active substances) to 42 systems.


Concerning the USCG, sixteen (16) systems have been granted USCG Type Approval so far (as of February 2019). In the second half of 2018, there was a frenzy of Type Approvals, with 8 BWTS systems approved.

We all agree that a BWTS retrofit project is a major undertaking. It needs to be cost effective, perfectly planned and executed with quality in mind.

There are a number of steps that need to be completed for a BWTS retrofit, or any retrofit for that matter, to be successful. The more time you focus on completing each step correctly, you’ll get fewer of those unwelcome surprises down the line at the shipyard.

There are 15 important steps that make up a BWTS retrofit:

  1. Scan market
  2. 3DLS survey
  3. Feasibility study
  4. Verify fitting
  5. Negotiate terms
  6. Order equipment
  7. Accept design
  8. Class submission
  9. Drawings and specs
  10. Yard offer review
  11. Order spaces
  12. Sign contracts
  13. Equipment transport
  14. Service engineers
  15. Time to build

I would like to continue with a BWTS case study in order to give you an understanding of the required timeframes. When the Feasibility Study of a vessel starts in March, it will be completed by May and the placement of the order for the selected system should take place. Then, another two to three months are needed to submit class drawings - we estimate by the end of July. The Engineering Study with the detailed drawings and technical specification will be delivered to the client in August. This is three months before the equipment will be delivered to the awarded yard approximately in November. The final step is installation and commissioning. This requires approximately 20 to 30 days to be completed. As we can see, a BWTS retrofit installation requires 8 – 10 months from the Makers selection to the vessel’s arrival at the shipyard.

If you think that’s a long time, things have been complicated further by the additional scrubber retrofits.

In 2016 the IMO MEPC set 2020 rather than 2025 as the date for ships to comply. In 2017 there was still time. Scrubber makers received multiple requests but almost zero orders. It took at least one year, even more, for shipowners to be persuaded that fuels will be both expensive and unreliable, at least for the first or couple of years following the Sulphur cap.

Then, in the first half of 2018, scrubber orders were placed en masse with installations scheduled even in the same year. The Q4 of 2018 saw a frenzy of scrubber orders as well. Now September is just around the corner and large numbers of vessels require retrofitting.

USCG extensions are either expiring or not being granted. Consequently, a very large number of vessels need to be compliant soon. At the same time, scrubber installation, planning and retrofitting, time has been shorted from one and a half reasonable years down to barely feasible 3 to 4 months.

This leads to a reduction of valuable resources. Engineering teams and classification societies have found reserves and contingency plans stretched to the limit.

Scrubbers haven’t just come in a bad time - the hurried installation means that quality is also taking a back seat.

One way to deal with this unpleasant situation is to do at least the minimum necessary planning. We need to compromise of course.

We must never forget that Engineering is a Spiral process. It starts with the development of a basic design. It then progresses in cooperation (and with valuable input from) Technical Management. Finally, principal and detailed drawings and technical specifications must be approved by the Classification Society.

Keep in mind that, during the retrofitting process, there are a lot of factors that can cause delays. We’ll call these the Planning Pain Points. They are:

  • Classification Societies

First Pain Point: Class approval of EGCS/BWTS is not yet a routine process. These retrofits create new engineering challenges. Often, Classification Societies face unexpected and excessive workloads.

  • Supplied items

Some owners decide to purchase all items in order to reduce their retrofitting cost. While doing so they are risking mistaken / delayed deliveries. Needless to say, this might be the perfect excuse for the shipyard to delay the retrofit.

  • Shipyards

It is estimated that approximately 300 Capesize Bulk Carriers, VLCC and Suezmax Tankers are going to install a scrubber this year. This will increase the dry-docking dates by at least 15 days per installation for each vessel – or 3.000-3.500 in total. I think, it’s safe to say that in 2019, shipyards will be Celebrating the Year of the Retrofit!

  • Transportation of Equipment

We should not underestimate the time required for transportation of Ex-Works equipment to the shipyard and delays created by local authorities as well as customs requirements.

For example, we had a European BWTS maker and a ship-owner decide on a retrofit in China. The ship-owner selected a Chinese shipyard one week before arrival of the vessel. This did not leave enough time for the equipment to reach the shipyard. Sometimes we have even seen equipment transported by air which led to additional cost jeopardizing the overall budget of the project.

Having outlined all the above, I can’t stress enough how valuable proper planning is.

Even if we don’t seem to find enough time to plan, we need to focus on two things:

  1. Make sure that Engineering doesn’t take a back seat during the retrofit installation.
  2. Keep an eye out on Pain Points and manage your schedules effectively, given limited time.


Above text is an edited version of Mr. Dimitrios Ioannis Kalfas’ presentation during the 2019 SAFETY4SEA Cyprus Conference.

View his presentation here


The views presented hereabove are only those of the author and not necessarily those of  SAFETY4SEA and are for information sharing and discussion purposes only.

Dimitris holds a Diploma in Naval Architecture and Marine Engineering by National Technical University of Athens NTUA.  Before joining ARGO NAVIS, he has worked in a major engineering firm in the Oil & Gas sector as a junior project engineer.  He has joined Argo Navis in 2016 and has been involved in numerus engineering studies for BWTS retrofits. Currently he is one of the Engineering team leaders of the firm. During this time he has gained experience with most of the major BWTS makers. Dimitris has been also the supervising engineer in three BWTS installations in China, Malaysia and Romania.