Study Finds Use of Wingsails on Seismic Exploration Vessel Reduces Fuel Consumption 5-10%

17 May 2008

An earlier implementation of wingsails on the mv Ashington.

A study evaluating the use of wingsails on a seismic exploration vessel found that they could reduce fuel consumption by 5% when the vessel was towing its hydrophonic cable assemblies. The researchers concluded that the savings could double when the assemblies are not deployed.

The study, performed by CFD norway as, was commissioned by wingsail developer Shadotec plc in partnership with Wilhelmsen Marine Consultants (WMC) and Petroleum Geo-Services AS (PGS) to estimate the potential savings in fuel consumption achievable by employing Shadotec wingsail thrust units to assist in the propulsion of ocean going vessels. The Norwegian Marine Technology Research Institute (Marintek), based in Trondheim, Norway, will contribute to evaluate maneuverability and seakeeping.

The initial project evaluated the feasibility and potential of fitting two fully automatic computer-controlled Shadotec wingsail thrust units on a PGS 102-meter Ramform seismic exploration vessel fitted with 30,000 bhp of engine power needed to pull its kilometers of hydrophonic streamers.

CFD norway concluded that a PGS vessel fitted with two Shadotec wingsails, towing a typical array of hydrophonic cable assemblies at its standard speed of 5 knots, in a typical North sea wind, could reduce fuel consumption by more than 5%. When the cables are wound in and the ship relocates to its next field of exploration, CFD norway confirmed that the fuel and pollution savings might be up to double that.

An earlier computer-controlled wingsail fitted to a 102-meter, 2,000 bhp, 6,500 dwt dry cargo vessel—the mv Ashington—delivered average fuel savings of around 8%, and savings of up to 15-20% under favorable conditions.

This is a most exciting project. Shadotec now has significantly more advanced technology, and two of these great new generation wingsails fitted to a conventional ship like the Ashington could probably reduce her bunkers bill (and pollution emissions) by perhaps 30%-40%. Initial tests on our new technology suggest that we can offer up to 25% more thrust per unit area than before, with significantly less air drag. This means that more of our thrust will go to pushing the ship.

—John Walker, Shadotec Chairman, and designer of the wingsail fitted to the Ashington

The Walker-type Shadotec wingsails are set up vertically, thrusting horizontally, as a horizontal aircraft wing provides vertical lift. The wing unit is mounted on a freely rotatable bearing, and its angle to the wind is controlled by a vane. Because a thrustwing must work equally well with the wing coming from either side of the boat, everything must be symmetrical, or capable of making an asymmetrical set of mirror images, which can be brought back to symmetrical for the neutral case, where no thrust is needed to either side of the wind.

Project partner PGS is an oilfield service company principally involved in providing geophysical services worldwide. It has committed a substantial cash contribution into the present research project.

The initial results of the independent CFD norway study are encouraging. The potential savings would represent a considerable reduction of outgoings per ship in bunkers costs while simultaneously cutting down pollution. We are of course very keen to save money, but we also want to do as much as we can to reduce our carbon footprint, in our efforts to combat the increasingly worrying evidence of accelerating climate change.

Of course, the proposed installation of Shadotec wingsails on to our ships must satisfy rigorous requirements for return on capital invested and a wide range of technical and practical ship operation criteria. That said, we are cautiously optimistic, and we look forward to taking the project further.

—Harald Sundby, a senior manager in PGS