The benefits of wind assistance depend on its routeing (image: DSIC)
Intertanko paints a bleak picture for tankers under current EEDI plans, in which flaws in the IMO’s initial EEDI baseline could imperil VLCCs as a vessel type.
“VLCCs may fall out of use in favour of smaller tankers,” Intertanko told the IMO’s Marine Environment Protection Committee (MEPC), which it invited “to note the inherent consequences which may eliminate the VLCC design which is the most fuel and energy efficient ship type ever built.”
That stark warning was contained in the preamble to a submission it made to MEPC 75, which was due to meet in the first few days of April, and reflects the organisation’s significant concerns about the impact of EEDI Phase 3 if it comes into effect as planned in 2025.
Its full argument and supporting data can be found online in the IMODOCS database as document MEPC 75/6/4, but the organisation’s technical director Dragos Rauta outlined his concerns to The Motorship, saying that they stem from IMO’s initial EEDI baseline, which he described as a theoretical “line in the sand”.
It was based on data from tankers of all sizes was “not mathematically drawn” and does not necessarily reflect reality, he said. Intertanko’s submission to MEPC 75 summarises its analysis by saying that, in order to have a single line covering the full range of tanker sizes, “the baseline was originally drawn below the average of the existing ships in the VLCC size range.”
Mr Rauta compared the situation with that of container ships, saying that the base line for similar sized vessels was set 2.5 times higher than for VLCCs, yet they had the potential to reduce their EEDI simply by reducing speed, which demonstrates that “EEDI is an artificial concept”.
He was not impressed, either, with the potential of wind assistance, referring to the 300,000dwt VLCC New Vitality, which was fitted with two sails and delivered by Dalian Shipbuilding Industry Corporation of China in November 2018 to China Merchants Energy Shipping.
According to a presentation in September 2019 by Dalian’s head of R&D Peng Guisheng, without the sails, the ship’s EEDI would be 19.5% below IMO’s baseline, meeting EEDI Phase 1, and 21.1% below the line with the sails in use, which meets Phase 2.
However, Mr Peng’s presentation noted that “the calculated EEDI contribution of wind propulsion system closely depends on the routes selected,” claiming that on selected routes, the ship’s EEDI could be 35.5% below the baseline, which would meet Phase 3 requirements.
Mr Rauta acknowledged that in some circumstances the sails may deliver a useful benefit, “but that’s occasional and is not stable,” he said. Nonetheless, China Merchants placed orders in May this year for two more VLCCs, one to be fitted with four sails and the other to use air lubrication.
Even bulk carriers enjoy a better deal that tankers, Mr Rauta suggested. Following an initiative from Brazil, the baseline for bulk carriers has been adjusted so that its value is constant above a particular deadweight, but this would not work for tankers, he said, because the wide variety of tanker sizes would make it difficult to set a similar inflection point on the baseline.
Having presented it with the prospect of VLCCs becoming unviable, he hopes IMO will be willing look for a solution. Its paper to MEPC 75 concludes by saying that “it may not be reasonable to expect VLCCs to achieve Phase 3 with a safe level of minimum power, prior to the switch to alternative fuels,” but says that Intertanko “does not propose a modification of the EEDI Phase 3 requirements.”
It does not, however, propose a solution to this situation. “Although the initial intent of this analysis was to consider suggestions for possible changes … Intertanko members concluded that it is up to designers and builders to provide compliant as well as safe ships,” it says.
But this is not the end of the story. “We’re going to do to do more work on it and see what can be done without altering the altering the regulations,” Mr Rauta said, explaining that the paper was intended to inform IMO of the potential situation “so it does not come as a surprise to IMO in a couple of years.”