Speed limits for Ships! can have 'massive' benefits

a reply to: FredT

Imposing such limits on highways does make more logic sense right? but on the ocean?

The number of vessels at sea is staggering. So if people can wait a few more days, alot of emissions could be reduced. Obviously items like food, livestock etc are way more time sensitive than say a shipment of cars so that also would play into things.

Not to mention the shipment of medicine like blood sugar etc. and other important supplies.

What they don't tell you!!!

Most container ship carry between 20% to 98% frozen or chilled containers.

Running them 20% slower may mean less fuel used by the ships drive engines BUT at the same time they use 20% more fuel in the generators to power cooling the containers of food because of the longer time port to port.

In this case no fuel saved and in some cases more fuel used.

a reply to: ANNED

Most container ship carry between 20% to 98% frozen or chilled containers.

Source?

BUT at the same time they use 20% more fuel in the generators

Good point, the study does not seem to address the point. It should certainly be considered. Can you support it with something other than a claim? Are the containers not insulated? How much fuel is actually used to cool them, in comparison to that used for propulsion?

For the Los Angeles to Honolulu run, that 20% speed reduction would amount to about 1 day longer. When I drive slower, I get better milage, AC on or not.

as i have just spent breakfast advising a freind on boat specs

most vessels - are designed SPECIFICALLY for thier 1st owners intended cruising speed .

only naval vessels and speed boats typically have optimisation for fastest possible speet @ max revs

this is important - because - its unchangeable - well you CAN change props and gearboxes

but the hull-form is a integral part of a vessels design speed

and suddenly deciding that cruise speed is going to be different - is not going to get you the fuel saving you think

a reply to: RAY1990

hmm - why am i not surprised

its my opinion that strikes between large vessels [ 5ooo ton + ] in open water are very rare - and have no correlation to vessel speed

how is droping from 15 kt to 12 kt [ the " typical impact on a general cargo ship ] going to make any statistical difference

thinking about it - i suspect that most whale strikes are hi-speed boats - in " whale watch " areas

there was a issue several years ago - with mannatee strikes in the coastal waters araound florida - and speed limits were introduced to combat that

but the farce being foisted hear is a blanket " reduction " - not a speed limit

and given the big variations in speeds i see very little logic to it

a reply to: ignorant_ape

So even small improvements make a difference over the long hual.

Case in point: Whitcomb WInglets. We see them on most planes these days. Why? They reduce drag from anywhere to 2-5%. I know it does not sound like alot, but fatored over a million miles, you really see the benefits. We are talking billions. That same savings would also be applied to shipping

Winglets Save Billions of Dollars in Fuel Costs