By Steve Goreham
Originally published in TheT&D.
Occasionally a report appears which claims to be wisdom, but after careful analysis, offers solutions that don’t make much sense. Such a report was issued earlier this month by United Kingdom consulting firm GL Reynolds, titled “The multi-issue mitigation potential of reducing ship speeds.” The report proposes that we can reduce global warming by imposing speed limits on ocean-going ships.
The GL Reynolds report concludes that a 10-20 percent reduction in ship speeds would have a “highly positive potential impact” on carbon dioxide (CO2) emissions and nitrous oxide (NOx) and sulfur oxide (SOx) pollutants. The report also projects that a ship speed reduction may reduce fatal collisions with whales.
The report is actually conservative and recommends that more study is needed. But the BBC and environmental groups now hail the report as a roadmap for international maritime policy.
Matt McGrath, environment correspondent for BBC News, wrote “Cutting the speed of ships has huge benefits for humans, nature and the climate, according to a new report.” John Maggs from Seas at Risk told the BBC, “It’s a massive win, win, win, win.”
According to the International Transport Forum, ships carried 10.7 billion metric tons of freight in 2017, 70 percent of world freight volumes. ITF projects maritime freight volumes to triple from 2015 to 2050.
Like almost all modern transportation, ships emit carbon dioxide when they burn fuel. Ships emitted about 932 million tons of CO2 in 2015, about 2.6 percent of global emissions. When ships move at lower speeds, they consume less fuel and emit less carbon dioxide. A 2017 study by CE Delft estimated that a 20 percent reduction in commercial ship speeds would reduce CO2 emissions by 19 percent, after a required 13 percent increase in the number of ships to provide the same transport work.
In 2017, the value of the world shipping fleet was estimated at $829 billion. Increasing the size of the fleet by 13 percent would cost over $100 billion, plus additional costs to hire and train additional crews.
Today, most global corporations practice cycle time reduction as a key business process. Apple, currently the world’s most valuable company, calls it “reducing time to value.” On-line retailing giant Amazon implemented one-day delivery for many products this year. Footwear and apparel producer Nike announced a goal to reduce supply chain lead times by 83 percent.
Regulations to reduce the speed of ocean-going ships by 20 percent would increase cycle times and costs for the shipping industry. Crews would need to be paid more for longer voyages and each ship would take 20 percent more time to deliver the same cargo. Cycle-times and costs would also increase for Apple, Amazon, Nike, and all freight customers.
Advocates point out that emissions of sulfur oxides and nitrogen oxides can be reduced with slower ship speeds. But international regulations are already in place to reduce SOx emissions by reducing the sulfur content of fuels and to reduce NOx emissions through new diesel engine emission standards.
Collisions with whales have been rising with the growth of the world shipping fleet. National measures such as routing and speed restrictions are now in place in coastal whale migration areas at certain times of the year to reduce collisions. But how will increasing the number of ships by 13 percent reduce the number of whale impacts?
In 1975 during the first oil crisis, the US federal government imposed a National Maximum Highway Speed Limit of 55 mph. Officials estimated that lowering highway speeds would cut national gasoline consumption by over two percent. Later studies showed actual savings to be less than one percent. Today the world is awash with petroleum and the US 55 mph limit no longer exists.
We could certainly run our ships, planes, and vehicles at slower speeds. And if we returned to horse-drawn wagons, vehicle collisions with deer would be eliminated. But does anyone really think this would stop sea levels from rising?
Steve Goreham is a speaker on the environment, business, and public policy and author of the book Outside the Green Box: Rethinking Sustainable Development.
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10-20 percent reduction in ship speeds would have a “highly positive potential impact”
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Nope. Cargo ships create waves which ultimately limit the speed of the ship. The number of waves is determined by speed and waterline length. The speed of the ship is optimized when these waves line up on integral values with the bow and stern.
As such reducing speed may or may not save fuel.
Ships with bulbous bows are designed to be efficient when the bow wave from the bulb cancels the bow wave from the bow by being out of phase. This happens at one particular speed and reduces wave-making drag. If you slow the ship, you lose the fuel saving effect of that.
In business consulting there is a term TCO “Total Cost of Ownership”.
When investment is evaluated, TCO is calculated to the end of product life cycle – including recycling costs and dismantling etc.
Proposal to reduce boat speed might be a smart thing to do from pure fuel economy point of view, but he should have presented all the involved costs preferably on a time line. Is TCO recuded or not?
He is smart to talk about CO2, because if he would talk about fuel cost and vessel construction savings it would sound like dirty capitalism. Instead he takes opportunity to put lipstick on a pig and made it sound like a virtue.
So my guess is, that cost savings for ship building and operation is behind this. Not CO2.
” reduce global warming by imposing speed limits on ocean-going ships.” Making ships take longer to reach destinations means burning MORE fuel. Yea, that will “help” the environment. Another pack of maroons self identifies.
You’ve hit on a great excuse to try the next time you’re pulled over for speeding, “Sorry officer but I’m low on gas and speeding to get to a station before it runs empty.” (/sarc)
At 100% utilization, if the current number of ships supply X amount of commodity per year at 30 knots, they will supply 1/2 X amount per year at 15 knots requiring twice as many ships.
This appears to be a wonderful idea for the ship building industry!
Few if any merchant ships except small hydrofoil craft travel at 30 knots. It requires massive power. The United States needed 240,000 shp to move 53,000 GRT at 35 knots. And that was a small ship by modern standards.
And a single Boeing 747 has about four times more capacity measured in passenger-miles per hour.
The actual speeds are thoroughly irrelevant to my point, it could have been 4 and 2.
Not certain how your passenger MPH applies to cargo and what you are comparing it to?
The total world merchant fleet is about 2 billion tons deadweight. A 13% increase would amount to about 250 million tons deadweight.
To make one ton of steel produces slightly less than 2 ton of CO2.
Now calculating the amount of steel needed per ton deadweight is not easy, but clearly the amount of CO2 needed just to produce the steel for the additional ships would certainly run into 8 figures, not counting the energy needed to turn that steel into hulls, machinery etc, nor the extra infrastructure needed.
Under international treaty bilge water is not pumped over the side but into on-board tanks. These are empty into special treatment plants ashore. Also ship employ a machine called an oily water separator to extracted the oils from the contaminated bilge water. Spent many years fitting anti-tampering devices to this stuff so it was difficult to circumvent.
OK, I’m late to the party, but, I want to see the math. Maybe slower means fewer emissions, but they are produced for a longer time. Zero sum??
When the ‘Arab oil crisis’ hit in the early seventies, one response was to reduce the standard speed of new-built merchant shipping from 16 knots to 13 knots. This was the cruising speed that a vessel in good condition could reasonably be expected to attain at 85% of MCR (maximum continuous rating) of the main propulsion machinery. The 85% figure had been determined from practical experience to be (roughly) the highest power that could be sustained without suffering excessive wear rates.
There are several design factors influencing fuel consumption and, as 2hotel9 pointed out above, the extra time taken to complete a slower voyage does take some of the shine off the reduced fuel consumption rate. I believe that, in the late seventies (or early eighties), a study was done on the effect of the reduced speed, and it concluded that the benefits hardly justified the effort. There were some pretty sophisticated energy-saving ideas that looked good and had capital (and ongoing maintenance) costs that would never be recovered over the operational lives of the vessels they adorned.
Now, of course, we are not saving merely fuel, but the entire planet! It is therefore to be expected that any crackpot, virtue-signalling idea will be given weight far beyond its practical merits. Be prepared for a rerun of the fuel-economy-obsessed seventies.
In reality the weather and ocean waves play a far bigger role in the power it takes to move a ship at any given speed.