In this section, clicking on an image will usually enlarge it

There are several dimensions to analysing the varied fleet remaining after discussing Cargo Ships, Tankers and Passenger Ships. Inevitably they are crude when applied to a broad study such as this one, and there will be very fuzzy edges between any groupings. Apologies for that. To simplify things a little, I shall concentrate on the view from the UK.

A very useful classification has been developed in studies of European Road Transport where several EU projects have sought to assess what needs to be done. The results of one such study by FEV are reviewed in section 14 below. From that study I have borrowed the classifications

• Long Haul
• Regional Distribution
• Local Delivery

With that in mind, the fleet divides roughly into 2 types of vessel

  • Vessels capable of operating more than 10 miles off a coastline, but capable of penetrating much of the European river/canal system . Such vessels need to be seaworthy and have sufficient power to penetrate the larger rivers upstream. For example, vessels of up to 4000dwt operate from UK and Irish coastal ports (such as the Dublin, the Humber and the port of Goole) into the Rhine system as far as the Ruhr. Vessels of 1500dwt can ply between the UK East Coast ports, such as Goole, Boston or Ipswich, up the Rhine as far as Basle, and even beyond into the Rhine Danube Canal and down the Danube to the Black Sea. Such vessels need to be capable of proceeding upstream in the Rhine in all but severe flood conditions. All vessels need to respect some air draft limitations, and some even have retractable superstructures. Therefore wingsail installations will be the exception rather than the rule. Such vessels fall into the Regional Distribution classification and their power requirements will be similar to cargo vessels of that class. At the smaller size range, the power units will be similar to those used for road haulage, so the LEV study in section 14 is likely to apply in many cases.
  • Vessels only capable of operating in or near ports; or within the European River/Canal system. . In addition to the extensive canal system in the Low Countries, these vessels will range into Germany, and south into France and the Rhone Valley. These vessels need a low air draft, and must be capable of proceeding upstream on the major rivers including the Rhine and the Rhone.Therefore wingsail installations will not be appropriate. Typical sizes range from a few hundred tonnes (which can be classed as ‘Local Delivery’ ) to about 1500tonnes dwt (which will be in the ‘regional distribution class). Power requirements will be similar to equivalent classes of cargo vessels.

In the remaining sections of this study I have tried to refer to the appropriate application cases from the Joules Project, rather than group them altogether. Then each section will address traffic issues.Additional insight may be gained by comparing each vessel type with the appropriate aspects of the LEV study reviewed in section 14.

#12.1 An Urban Ferry Concept

(A ) Joules Project Application case Urban Ferry
The suggestion is that diesel engines, even using dual fuel, could be replaced by 2025 by compressed natural gas (CNG) to yield up to 50% saving inCO2 production. This seems to be an extremely unlikely outcome except for a few pilot cases as there is insufficient time now to make any significant proportion of the fleet compliant with this aspiration.. The longer term projection for 2050 is that very short sea ferries will be operated by battery power (recharged at the terminals) mixed with fuel cells. That seems possible if, and only if, sufficient shore power can be made available from sustainable sources. The LEV study in section 14 references local distribution vehicles, which is similar to the Urban Ferry requirement.

#12.2 Joules Project Inland Cruiser concept

(B) Joules Project Application Case River Cruiser
The Joules Project addressed the unusual requirements of river cruising for ability to proceed upstream at slow speed, and to proceed downstream at a similar slow speed causing light load conditions on a diesel engine, which can cause inefficiencies.
The proposal for 2025 technology was to use a diesel electric propulsion system with the power supplied as DC electricity from 4 diesels (so the number in use could be reduced when going downstream). Domestic (hotel) services would be maintained by fuel cells. The result would be a 29% reduction in Global Warming Potential.

#12.3 Inland Waterway Powertrain options

Using an all-fuel-cell solution by 2050 could improve the GWP saving to 94%
Surprisingly, as these vessels spend considerable periods of time alongside, no mention is made of the potential use of shore power.

I am unable to separate out the inland vessels in The Marine Traffic Plot but as the characteristics are broadly similar across a wide range of ship types, I have combined several appropriate ship types, which make some of the inland traffics and short sea clusters more obvious.

#12.4 Marine Traffic European coastal and inland waterways traffic plot

Plot #12.4 shows the European coastal and inland waterways traffic. There is a lot of it! Note particlarly the strands of inland waterways traffic which justify a more detailed look.

#12.5 Marine Traffic Plot showing river/canal system between Baltic and Caspian/ Black Sea

Plot #12.5 shows the significant traffic between the Baltic and the Caspian and Black Sea with a spur to Moscow. Traffic is seen to be dense, and we have already established that traffic in Russia is probably underestimated

#12.6 Marine Traffic Plot showing low countries inland waterways, the Rhine Danube Canal and the Baltic Traffic

From Plot #12.6 it is evident that UK coasts, the Rhone Valley, the Baltic, the Low countries (Belgium, Holland)  and the Rhine Danube route generate considerable traffic. All round the European, Mediterranean, Black Sea and Caspian coasts generate short sea traffic.

#12.7 Marine Traffic Plot Inland Wateways of N America

Plot #12.7  shows activity in North America. There is significant inland or coastal traffic

  • The Great Lakes, where distances between ports and distance offshore are such that most operations should be classed as ‘regional distribution’.
  • The Mississippi, where all operations are essentially river traffic. Many special vessels have been developed for this trade, including tug-barge systems.In terms of power requirements these will probably range between ‘local distribution’ and ‘regional distribution’ requirements
  • West Coast Canada, where there is a strong coastal trade north of Vancouver, some of which is tug-barge. This is more likely to fall into the ‘regional distribution’ class as far as power requirements are concerned.
  • As an aside, the absence of traffic showing in the Caribbean may indicate that AIS services are not well established in that area, adding to the suspicion that total shipping may be underestimated.

#12.8 Marine Traffic Overview of Far East Shipping

Plot #12.8 shows the Far East shipping. It tends to be swamped by the deep sea traffic routes, but the sheer density of traffic around Japan. Korea, China, Indonesia and the Phillippines indicate the probability of a mass of short sea activity, which I believe to be underestimated by the Marine Traffic plot. It illustrates the practical difficulty of getting international agreement to convert this varied fleet to zero carbon. For very short sea applications, it cannot be assumed that renewable electricity will be available, and upgrading the fleet may not be possible in underdeveloped countries. We can only assume this fleet will range between ‘local distribution’ and ‘regional distribution’

#12.9 Marine Traffic  Detail showing Yangtse River traffic

Plot #12.9 is slightly zoomed in to show that there is significant traffic on the Yangtse River which serves Shanghai. There are other river systems in China which do not show significant river traffic on the Marine Traffic plots, which may indicate anunderstimate of the fleet size.

The broad conclusion about short sea and inland waterways vessels is that there is potential for reducing Global Warming Potential, but it involves a vast number of vessels covering a range of sizes and types of service. Much of the fleet is in developing or underdeveloped countries where the will and resources to effectively upgrade the fleet will be in short supply. While good reductions in GWP are achievable, it seems unlikely that there will be much progress by 2050 unless there is a dramatic change of political will.

The keyword in this segment is ‘variety’. The Joules Project selected a few vessel types, but could not possibly cover all the ground.

(A ) Application Case Harbour Tug

#13.1 Joules Project Harbour tug

The Joules project study addressed the problem that tugs pack a huge amount of pulling power, but spend much of their time in light load condition. That suggests the short term (nominally 2025) options including a hybrid solution, partially utilising shore power to ease the variable power demand, offering a reduction in Global Warming Potential of about 30%.

High powered fuel cells are expected to be available by 2050. Use of biogas to feed the fuel cells is suggested which would be a zero carbon solution. Overall, a GWP reduction of 90% could reasonably be expected.

(B) Application Case Dredger

#13.2 Joules Dredger

This study revealed an unexpected problem and an ingenious solution. It seems dredgers often experience sudden large demands for power because of the uncertain nature of the terrain they are tackling. So the 2025 proposal was to use LNG combined with a hybrid power supply and a flywheel (!) That solution would reduce GWP by 26%

The 2050 proposal relies on a hydrogen based fuel cell, and eliminating the crew. It is estimated that this would reduce installed power by 40% compared to the baseline. Overall, a 75% reduction in GWP is predicted.

This is the only case where automating the ship operation and eliminating crew is considered. Perhaps other projects should be reviewed again to see if further GWP gains could be made by this approach

(C ) Application Case Offshore Patrol Vessel

#13.3 Joules Project Offshore Patrol Vessel.

Patrol vessels spend much of their time at low speeds, or in port, with occasional needs for high speed and power. The Joules Project proposal was for a hybrid system combining two forms of propulsion, use of shore power,  and the use of alternative fuels such as LNG. As this type of technology is already fairly common, a modest GWP reduction of 20% is expected by 2025.

The 2050 hybrid propulsion system is enhanced with the foreseen development of high power density electric machines, electric storage systems and fuel cells
Reference is made to use of advanced fuels, but the use of hydrogen derivatives may further improve the projected 65% GWP reduction predicted for 2050

(D) .Application Case Offshore Support Vessel

#13.4 Offshore Support Vessel

There are numerous variations on this theme, including oil rig supply vessels, salvage tugs, standby vessels, and many more. The Joules project chose a seismic survey vessel, which has highly varied power demands, and the need for considerable endurance at sea.

The main proposal for energy saving by 2025 involved using low sulphur marine diesel blended with a Biomass-to-liquid fuel to yield a GWP reduction of 37%

For 2050, alternative ‘drop in’ fuels were considered to yiled a potential GWP reduction of 55%.

With later information it is possuble that a switch to hydrogen derivative fuels could improve this result.

(E) Application Case Mega Yacht

#13.5 Joules Project Mega Yacht

There are a surpising number of megayachts. Typically they spend most of their time in port, occasionally changing location (e.g. Mediterranean in summer, and Carribean in Winter). The Joules Project Team asserted that the need for flexibility means that most recent  vessels of this type are already diesel electric, so the scope for reducing Global Warming Potential is strictly limited. The study, inevitably, falls short of considering a switch to hydrogen based fuels, or making better use of renewable shore power.

I recently discovered an amazing article describing the next generation of supryachts. It makes a jawdropping read

#13.6 Typical 36 ft launch tyoe motor yacht

[My personal opinion is that there is a wider problem to be solved. Until 2019 I had owned a motor boat for 5 years. It had 2 turbo charged diesels totalling just over 500 hp. They were basically truck engines. I was regarded as an above average user, and I put on about 100hours per year burning about 3000 litres of diesel.  In my opinion these vessels will need to be re-engined. There are thousands of them, and managing that transfer will require political skill.

There are also hundreds of launches, pilot cutters, crew boats and mooring launches used in harbour areas that are broadly the same size. They too will need re-engining, probably with a hybrid fuel cell or ammonia based solution]

#13.7: Marine Traffic Plot: Tugs and Special Vessels

Looking at the Marine Traffic Plot #13.7, tugs and special vessels do not feature much away from coasts and harbours (the yellow dots are high speed craft that have been included in this class). Exceptions would be deep sea towage of such things as oil rigs; and survey and research vessels.

Many world areas seem to be devoid of tugs and special craft. Assuming this is supposed to include pilot vessels, cargo pontoons, floating cranes, bunker vessels, oil rig supply vessels, dredgers and other specialist vessels, this would indicate that in many areas such as West and East Africa, China, Russia, few, if any smaller vessels are AIS equipped. So this may be a significant area of underestimate of the problem.

The characteristic of this group seems to be a highly variable demand for power. Each application has its own special requirements. Broadly speaking hybrid solutions, eventually migrating toward hydrogen derivative fuels seem to be indicated. Where operations, such as tugs, are close to or in harbours, then use could be made of renewable shore power, if available, though that may be improbable in much of the developing and underdeveloped world.

#13.8 Marine Traffic Fishing Vessel Plot

A first glance at the Marine Traffic Plot #13.8 shows that deep sea fishing occurs in many areas worldwide, especially the Pacific Ocean and Southern Indian Ocean.

A closer look shows a surprising lack of vessels on the USA eastern seabord, the Chinese and Japanese coasts, the Mediterranean, Northern Indian Ocean and Indian coastline, Indonesia, Malaysia, Cambodia/Vietnam, Philippines. This probably indicates that the fleet (and/or the local coastguard) is not equipped for AIS reporting and this must represent a significant understatement of the shipping quantity in the fishing industry..

The fleet ranges from small inshore (artisinal) fishing vessels; through local vessels making trips of 1-3 days; to longer range trawlers supported by fish factory ships.Very large deep sea factory trawlers are capable of long voyages and with modern technology can scoop up vast quantities of fish. Means of regulating such vessels, and enforcing the regulations, even in UK waters, are urgently required.

There are concerns about overfishing. Already we have seen the collapse of the herring and cod fisheries. Environmentalists are concerned and are pressing for more regulation especially in the deep sea area. To some extent, overfishing has been amplified by technologies such as electronic fishfinding sonar and the ability to ‘fly’ mid water trawl nets to scoop up entire shoals. IT has been demonstrated that bottom trawling can cause serious damage to the marine ecosystem, and, certainly in the UK, measures such as ‘no take’ zones have been established in agreement with the local fishing community.

Much fishing is subsistence fishery. It is difficult to regulate and the worst excesses are likely to occur in under developed and developing countries.

Maybe the best way to migrate toward zero carbon operations will be through international conventions. The convention on whaling shows what can be done. This will tackle the ‘top end’ first. This may leave a long tail of small fisheries. But as these are operated by those that can least afford to replace boats or engines, this is probably a pragmatic solution.

Except for the very largest vessels, fishing boat propulsion is similar to that categorised as ‘regional distribution’ . So in the short term (to 2025) the expectation should be some migration to a form of mild hybrid systems. But to reach zero carbon will take more effort, possibly including the use of fuel cells. This will be difficult to introduce and regulate across such a large and diffuse fleet. Enforcement may prove impossible.

#13.9 Marine Traffic Plot of leisure Craft

The Marine Traffic Plot #13.9 shows that the fleet distribution appears to be dominated by Europe, N America and Australasia, though it is probable that many areas of the world have yet to see AIS installed on many pleasure craft. .

The Fleet falls into three categories

  • Superyachts (Sail and Power). These vessels,typically costing between £1 million and tens of £mllions, tend to spend most of their time in port, so are candidates for renewable shore power. Some move between Mediterranean in the summer and Carribean in the winter. Realistically, they are probably candidates for diesel substitutes. A few may be worth re-engining with hybrid solutions. As they get older, these superyachts tend to spend more time in port.
  • Motor Yachts (typically up to 20metres, mostly 9-15metres): 100 hr engine time per year is typical usage, but there is no doubt pressure will be brought to bear for these luxury vessels to approach zero carbon operation. Fortunately, many have the marine version of truck engines, so similar solutions to those suggested for regional distribution vehicles would apply.. This involves some mild hybridisation to improve engine efficiency and will get close to net zero, This could meet 2025 targets, but by 2050, re-engining may become necessary to meet regulations. Most motor yachts are based on grp hulls.
  • Sailing Vessels. Most of the sailing fleet is built from GRP hulls and uses synthetic sails and ropes. All of these are generally sourced from oil, I do not know whether the manufacturing process for these materials is zero carbon. While the fuel burn for sailing vessels is trivially small, the potential GHG production from the manufacture of the materials, and possibly their disposal could be significant.

#14.1 Overview of GHG targets for transport

Road transport can (mostly) be regulated nationally, so it is not surprising that the road transport industry already has a clearer idea of its future. Within the EU, clear targets have been set, and will be enforced subject to severe penalties for non-compliance. After some hunting, I found a useful webinar organised by the Dutch based FEV Group which was presented in July 2020.

The webinar can be viewed by using the search then choosing “Truck and Bus” under the SelectATopic tab. Then scroll down till you find the FEV webinar date 20 July 2020. (In August 2021, it was on page 2)

#14.2 FEV seminar statement of EU targets

The first diagram #14.2 shows the targets. Broadly speaking these seek a 15% reduction in GHG by 2025 and a 30% reduction by 2030, with severe penalties for failure (for example, a fleet not reducing emissions at all below 2019 levels would in 2025 incur a fine of approximately €40,000 per vehicle). (the remainder of that slide is rather technical and beyond the scope of this exercise)

#14.3 FEV Development Pathway

#14.3 shows the conceptual stages required to improve road vehicle GHG efficiency from present levels to the 2030 targets set by the EU.

#14.4 FEV Results.

#14.4 shows the overall conclusions, which indicate that the 2025 targets for GHG reduction can be achieved by

  • improving efficiency of existing engines
  • predictive management of the powertrain [The nearest equivalent in the marine world might be weather routing]

However, #14.4 shows that the 2030 targets which fall well short of the IPCC target of zero carbon by 2050, can only be achieved by radical new measures including

  • Some use of renewable fuels (usually blended with diesel) and
  • the introduction of a 48v hybrid system that can be integrated with present technologies

The FEV presentation goes into a quite detailed analysis that demonstrates that 2030 targets can only be achieved by

  • The introduction of new technologies such as electric propulsion for small scale vehicles for local delivery. [This corresponds roughly  to harbour and short inland waterway operations]
  • For regional routes, a combination of improvements to internal combustion engines and hybrid systems [This corresponds roughly to short sea passages, and relatively long inland waterway voyages – or a combination, such as from Ipswich via the Rhine to Basle or beyond]
  • Scaling up, for long haul routes, to  the introduction of hydrogen based combustion in existing engines and/or fuel cells. [This corresponds to deep sea voyages]

#14.5 Overall conclusions

The overall conclusions are summarised in #14.5

I have not found a similar study for the marine sector, but it seems improbable that the marine sector will move at a faster pace than the land based road vehicle sector

On this basis, the shipping sector will still have a long way to go to reach zero GHG emissions by 2050. It should also be noted that the land based vehicle sector already has in place specific targets, by vehicle type, and penalties for vehicles that fail these targets by specific dates.

It may well be that the marine sector will need similar targets and penalties to those introduced by the EU for the road traffic sector, although how these can be administered on an international scale is hard to determine, especially in the face of the lethargic performance of IMO.

Greenhouse gases could be generated by creating the materials from which ships are built, and may be released when they are scrapped.

Is there a case for Classification Societies being given the responsibility for taking into account these factors before approving materials used in shipbuilding? Is there any chance that international agreement to do this could be reached?

The Wikipedia entry on Ship Breaking contains much useful information, and is commended.

Shipbreaking is an essential process, all the more so as the fleet will have to be converted to a zero carbon status. Some progress will be made by refitting ships, but many existing vessels will not be able to meet the new requirements.

Much useful, recyclable material (particularly steel) can be recovered from redundant ships. However, ships contain many toxic materials.

As for the environmental effects, Peter Knego, journalist and ocean liner historian, said “shipbreaking practices can be a problem, despite strict regulations.
“There are higher standards today, but the beach in Alang (India) is still rather toxic with PCBs, leaked fuel, paint and other toxic substances. The amount varies from yard to yard and how environmentally conscious the specific breakers are. In recent years, there has been an asbestos abatement program where the asbestos is burned at extremely high temperatures and buried in sealed pits.”

While GHG emissions resulting from shipbreaking may be small in relation the overall GHG generated by shipping, it is an area that should not be overlooked when considering the overall GHG footprint of the shipping industry. Mechanisms for managing the life cycle GHG emissions of ships using Classification Societies or government agencies may be required.

Click Here to go to Zero Carbon Ships 1