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Why Britain needs a Net-Zero Shipping Alliance

Visualisation of the Windship

Shipbuilding for the future

Lars Carlsson makes the case for a revival of the British shipbuilding industry, to produce much-needed zero-carbon emission ships

About 40 years ago, Britain lost almost its entire shipping and shipbuilding industries to Asia. Government subsidies in Japan and Korea were blamed, but that was not necessarily the main reason. In Asia large, efficient, highly automated shipbuilding capacity was set up using the latest technology imported from European shipbuilders. And now China has taken over as the major player in all matters maritime. In most cases China’s national shipping companies have taken advantage of the supply of locally built ships, and over time efficient shipping clusters have evolved there.

Most European shipyards, handicapped by traditional work practices as well as higher wages and living costs, were unable to compete. Britain’s merchant shipbuilders, which had led the world, could not compete without continuous government support. But this was not forthcoming, and all the major yards, which were concentrated in areas of high population density, were consigned to the scrapheap. The resulting unemployment, with the loss of apprentice training and engineering skills, created the inevitable social dislocation from which many of those communities have still not fully recovered.

However, times are changing again. In Japan and Korea, salaries and wages are now relatively higher than in most parts of the UK, which is suffering from all the dislocation caused by the Covid-19 and other effects. So perhaps now is the time to assess whether the UK could re-establish its position as a leader at the high end of shipbuilding and marine equipment manufacturing, by creating competitive production within this country.

Climate change challenges

The innovative Flettner ‘rotorship’ Buckau in 1924
The innovative Flettner ‘rotorship’ Buckau in 1924. The system did not prove cost effective at the time, but there has been some revival of the Flettner system in recent years. Photo: PD

Ships have been powered by fossil fuels for more than 150 years, and shipping is now the sixth biggest source of greenhouse gas (GHG) emissions in the world, representing about 3 per cent of total emissions. Demographics and increasing transportation would mean that shipping emissions, if unchecked, could reach about 10–20 per cent of the global total by 2050. However, legislation recently enacted by the International Maritime Organization (IMO) aims to eliminate GHG emissions by 2050.

The situation is now accepted as serious, the only viable solution being for shipping to aim at achieving net-zero emissions well before 2050 – and preferably nearer 2030, before the damage to our planet is irreversible. This is a hard nut to crack, and various leading research institutes have calculated the cost of decarbonising shipping at more than a trillion dollars. Clearly there is not just a single answer, and it will be an evolving process: different solutions will be needed for short sea and deep sea shipping applications.

Let’s look at some of the alternative sources of natural energy currently being investigated. The obvious ones are hydrogen, wind and solar power, all of which can generate electricity. Over the last 40 years there has been progress in converting diesel engines to run on hydrogen, stored conventionally under pressure. Hydrogen fuel cells produce electricity in the same way as photovoltaic solar panels. Further innovation is taking place, to produce hydrogen from ammonia at the point of use.

But let’s consider the oldest source of natural energy, a source that has powered ships since time immemorial. Sailing has remained a popular leisure activity. Although most wind-driven vessels these days are fitted with conventional auxiliary diesel engines, they also have a multitude of different sail designs, which have evolved over the centuries into some of the most highly sophisticated systems we see today in the international yacht racing world.

It is only 150 years since merchant ships and warships moved away from sails and wind power first to coal-fired steam, and then to oil, as a more reliable source of propulsion. In the transition period some warships were fitted with dual systems: ‘Up funnel, down screw’. But the wind is still with us, and so are the old trade routes.

From time to time over the last 50 years a number of commercial wind-assisted sail technologies have emerged, such as the Flettner rotor system, designed to produce extra thrust to reduce fuel consumption; but these were all retrofit solutions and did not prove cost-effective. In any case the aim of reducing running costs has now been overtaken by the need to reduce shipping carbon emissions to zero. It is reasonable to expect that many of the ships in the world’s merchant fleet today will become uneconomic to operate under the new emission regulations, and that there will be a consequent demand for entirely new designs and innovative concepts.

A radical new design

In the R J Mitchell Wind tunnel at Southampton University
In the R J Mitchell Wind tunnel at Southampton University, using smoke to study the airflow around a one-twentieth scale model of the Windship triple aerofoil. Photo: Windship

As a former shipowner responsible for operating a large fleet of oil tankers, I have been fortunate enough to work with a team of clever engineers, naval architects and shipping experts investigating new solutions from basic principles. The team has developed several very exciting concepts combining forces of natural energy that can produce a net-zero propulsion system for bulkers, tankers and other types of merchant ships.

At the heart of the design is the efficient combination of a sail-assisted propulsion system combined with an innovative diesel-electric ‘drive train’. The sail rig is a triple-wing foil set rotating on a single bearing, offering the highest power density of any wind system currently known. The electric drive system is powered by diesel-driven generators, using zero-emission advanced biofuel and giving full control over the power supply: the overall efficiency of the drive train allows for variable load and torque at 98 per cent efficiency under all conditions. Compared with a conventional ship’s engine, this system is of similar efficiency as far as the gearbox, where only 3 per cent loss would be expected, whereas in a standard ship’s engine any change from optimum revolutions results in substantial efficiency losses.

The question is: could these wind rigs and the diesel-electric drive train kits be built in the UK? There are several reasons why they should be, the most important being the ability to maintain strict quality control. In addition, this would generate a culture of constant innovation and improving performance, continually seeking better solutions. Further, keeping the technology within UK control would forestall copycat production by competitors.

Employment in the North and Wales

Discussions on the production of the wind-assisted sail propulsion rigs and the power generator packs are at an advanced stage with one of the leading UK shipyards. The firm is based in industrial areas with widespread unemployment, where basic engineering skills are still available.

Establishing several sophisticated production facilities for high technology production in the field of global emission reduction ticks many boxes simultaneously. Unemployment can really only be solved by sustainable industrial production with longterm prospects.

A solution to revive UK shipping

With appropriate government support, there are good prospects that high-end shipping could be brought back to the UK, and that British shipping could be restored to the forefront of world sea transport systems.

There is enormous potential for the net-zero emission ship, and its advent coincides with UK plans to return to a global position in maritime trade. At present this ship is the only viable net zero-emission solution available that is based on natural energy sources. The solution is both low-cost and technically viable.

The UK government has declared its commitment to achieving both net-zero emissions and for a UK maritime industry to meet its targets by 2050. Support for both these industrial projects within a UK Net-Zero Shipping Alliance would be entirely consistent with the creation of sustainable industries, which would be of enormous benefit to the UK economy. The even greater spin-off for the UK would be the creation of sustainable job opportunities in some of the UKs most job deprived areas.

Most of the major oil producers, including BP and Shell, have set targets of net-zero emissions before 2050. Oil companies are huge carbon emission producers, and net zero tonnage will dramatically reduce their transportation emissions.

All existing fossil fuel-powered ships will need to be replaced by net-zero ships over the next 25 years to comply with both IMO legislation and most shippers’ and investors’ net-zero requirements. This will result in a high demand for net-zero ships.

The IPCC has stated that global emissions must be reduced to net zero by 2050. This means that within ten years shipping emissions will need to have been cut by 45 per cent: that is, to below 2008 levels.

There is no time to lose.

Before retiring from Stena, Lars Carlsson was President of Concordia Maritime, Chairman of Intertanko and a board member of ABS. He is currently a director of Windship Technology, based in London, and the instigator of the UK Net-Zero Shipping Alliance. Further information about the net zero-emission ship is available at