Oman Shipping Co (OSC) chief executive Ibrahim Al Nadhairi readily concedes he was no fan of scrubbers when the Muscat-based company began preparing for the International Maritime Organization's 2020 sulphur mandate.

A chief engineer by training, Al Nadhairi headed up OSC’s technical ship management division in the run up to the new regulations.

“At the beginning we were not interested in retrofitting any of our ships with scrubbers due to the capital, installation and operating costs involved,” he told TradeWinds.

Today, Al Nadhairi takes the opposite view.

Installing scrubbers on OSC’s VLCC fleet has saved the company a significant amount of money, he claimed.

OSC decided to equip its three newbuildings then under construction with scrubbers, and retrofit its other 15 existing VLCCs.

The work is being undertaken at sister company Oman Drydock Co (ODC).

Eleven of OSC's 15 VLCCs have undergone retrofitting, with the rest expected to be completed this year.

Most of its VLCCs trade in the spot market, where Al Nadhairi claimed they are now enjoying a competitive advantage.

“Based on a price spread between high and low-sulphur fuel of $100 to $110 per tonne, we save between $3,500 and $4,000 per ship per day,” Al Nadhairi said.

OSC retrofitted its first VLCC in late 2019.

“We recovered our first investment within four months,” Al Nadhairi said.


Feen Marine's SOxBOX plug-and-play scrubber equipment can be quickly installed on a vessel's deck. Photo: Feen Marine

OSC selected Feen Marine’s SOxBOX scrubbers. Designed as a “plug-and-play” system, they are shipped as flat-packs and assembled and installed on a vessel's deck.

Feen Marine claims SOxBOX's advantage over conventional scrubbers is that they are lighter, cheaper and easier to install. And they do the job just as well.

OSC was the first company to buy SOxBOX scrubbers. Al Nadhairi said they have proven to be as good as promised.

Supply and installation at ODC costs about $2.5m per vessel, compared with between $5m and $6m for more complex designs. Installation is completed within 18 days, although ODC’s goal is to reduce this to 14 days.

"When we look over the full retrofit project lifespan, we estimate that using the SOxBOX will result in savings over conventional scrubbers of about $1,500 per day per ship," Al Nadhairi said.

OSC’s newbuildings have been fitted with conventional built-in scrubbers.

Low-sulphur fuel challenges

OSC has fitted scrubbers only on its VLCCs. Its other ships, which are mostly fixed out on long-term charters, have switched to low-sulphur fuel.

“Our charterers are happy with compliant fuel,” Al Nadhairi said.

Switching to compliant fuel has not come without issues.

Al Nadhairi said initially there were problems with catalytic fines and solids that blocked fuel filters.

“In several cases we had to debunker vessels and replace the fuel,” he explained.

“There were also incompatibility issues with bunker stems, even from the same supplier. We had to retune engines after each bunker stem. Maintenance issues caused ships to go off-hire.”

Al Nadhairi said the situation has improved, but the problems have not entirely gone away.

“It was an expensive learning curve. I’ve spoken to industry peers. They are all crying," he concluded.

Oman Shipping Co is carrying out scrubber retrofits for its VLCC fleet at Oman Drydock Co's shipyard in Duqm. Photo: Oman Drydock Co