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Stena flexes its design muscles

The Naval Architect November 2020


IMOFlexMAX-at-sea copySwedish tanker operator Stena Bulk prides itself on being forward thinking. In 2013, it set about revitalising its fleet with the IMOIIMAX class of oil and chemical tankers. Starting with the Stena Impression, a total of 13 of the 18-tank MR tankers were built by Chinese shipyard Guangzhou Shipyard International between 2015 and 2018. 

In June, the company unveiled a ‘prototype’ of its successor: the IMOFlexMAX. The concept design, which has been developed by Stena’s in-house team, Stena Teknik, draws upon the experiences of operating the IMOIIMAX, as well Stena’s expectations for the future in developing a solution that’s said to be both flexible and efficient. 

Erik Hånell, Stena Bulk’s president and CEO, tells The Naval Architect that the new design has been influenced in part by the changing nature of Stena’s shipments. “We have gone more towards trading chemical parcels, hence our need for one or two tank pairs of stainless steel which you see in our IMOFlexMAX design. We have also seen that the maximum 3,000m3 capacity tanks which we have on the IMOIIMAXes [which have a total of 18 tanks each] can be a bit unnecessary and have scaled up a few tanks for quicker operation.” 

Stena believes the new design will be able to cut greenhouse gas (GHG) emissions by 25-45% compared to equivalent product tankers currently running on low sulphur fuel oil (LSFO). In addition to enhanced hull design, there will be a variety of other energy saving technologies. Power will principally come from dual-fuel engines that run on LSFO and LNG, but supplemented by solar panels and Flettner rotors, which Hånell thinks offers a “cost effective” solution for GHG reduction and realising IMO’s carbon goals. 

For now, Stena is yet to approach any yards about placing an order for the IMOFlexMAX, but the plan is that they would be deployed in the company’s global logistics system, alongside the IMOIIMAX vessels. 

At the same time, Stena continues to keep its eye on the viability of alternative fuels with other projects. “We are turning every stone, like many shipowners are today, and looking heavily into fuel cells as well as hydrogen, but we believe this will be several years away,” states Hånell. “We have also invested in two MRs with Proman Shipping which will run on methanol, and Stena Lines’ ferry Stena Germanica has been running on methanol with good results… most likely we will see a mix of different solutions in the future depending on trading patterns and the size of the vessel.” 

Recent developments in the European Parliament have raised the possibility that vessels operating in EU waters may be compelled to comply with the Emission Trading Scheme (ETS) intended to curb carbon emissions. Unsurprisingly Hånell says that Stena, while supporting GHG reduction initiatives, believes international regulations are imperative for fair competition, rather than a localised approach.