Dasivedo’s Tig Rig system could help owners meet strict fuel rules

The Tig Rig system could provide substantial fuel savings for shipowners. Credit: Getty Images
The Tig Rig system could provide substantial fuel savings for shipowners. Credit: Getty Images

Meeting the International Maritime Organization’s (IMO’s) 0.5% sulphur cap regulation, which comes into force in January 2020, is akin to putting a man on the moon, according to Alistair Johnson, designer at Dasivedo, the innovators of the Tig Rig sail system.

“This is a bit like President [John F] Kennedy’s determination to land on the moon by 1970. This will focus the industry on the technologies and business plans needed to achieve this goal and puts Tig Rig in a very good position to benefit,” Johnson said.

Tig Rig aims to help the maritime industry achieve the cuts necessary to reach the IMO’s target. It consists of an array of sails that can be moved on a rail around the ship and raised, lowered, and redirected to catch the wind in the most efficient manner by using electronic controls from the bridge.

Tig Rig can be retrofitted on to existing flat-decked merchant ships, tankers, and bulk carriers, as well as some ferries and container ships. It is a two-part system consisting of square rigged sails in self-contained units that are mounted on fixed points around the hull.

“The mast and sails can be rotated through 360° and the sails can be reefed up and down in increments of tenths of sail drop. The mounting points are interconnected by rails that allow the units to be drawn around the ship and out of the way of dockside operations in port. A similar but more involved procedure allows the units to be gathered at the stern and bow for transit through canals,” Johnson explained.

As well as controlling the sails centrally from the bridge, electronic controls at each unit can be used or, if necessary, operated manually. “The Tig Rig units have automatic mechanical safety devices for automated reefing and automated mast release. These mechanical safety overrides prevent damage to the ship, mast, or sail through excessive wind,” Johnson said.

However, he noted, “For getting through canals and clearing the units to stern and bow, the procedure is more involved. The sails have to be reefed down and the booms and sail have to be removed from the mast. This allows the cleared units to be gathered closely enough to fit at each end of the ship.”

When fully deployed during testing, the sails showed significant results in fuel savings. Test data found that, for a ship travelling 12 kt, thrust savings averaged 8% and increased by 3% for every knot decrease in sailing speed.

Another attractive element of the Tig Rig system is its ability to get around what Johnson called the ‘split incentive’ in the timecharter market through the separation of the sails with the mounting units.

“Because owners do not pay for the fuel, they have no incentive to install fuel-saving devices. Because charterers have no long-term interest in the ship, they have no incentive either. With Tig Rig, the operators and charterers will be able to rent the units on a profit-share basis and be cashflow positive from day one,” he said.

As the deadline for the sulphur cap draws near, fuel-saving devices will become more imperative, particularly as many observers believe that the period immediately afterwards will see prices for distillate fuel rise substantially. In such a scenario, the ability to save fuel could be particularly attractive if owners and charterers share the wind power dividend.

Owners would be particularly interested to know that as the fixtures for Tig Rig are all above the waterline, there is no need to drydock the vessel. Johnson estimated that fitting the system would cost up to USD300,000 and could take 7–10 days to install, depending on vessel size.

Simple solutions could, in the final analysis, provide the best ones for solving the most complex problems. Wind power is not the only answer to the carbon conundrum, but it will play a significant role in finding a solution.

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