Sorry, that's a little Verilog. [4:9] means indeces [4][5][6][7][8][9], in other words, "martin".
The camry example was just an illustration of the power relationship of something moving through water. Nothing more than that.
The comparison of a container ship with 5,000 TEU (2,500 40 foot containers) vs. a train is, of course, different. And, of course, it isn't as simple as looking at cross-sectional area. That would be a gross oversimplification. Sometimes you have to assume that a cow is a uniform sphere of milk just to start to have some numbers to talk about.
Imagine a train design to carry containers at 200 miles per hour. Single file. So, now, the cross sectional area is that of a single container, which is very small. If the train is designed to minimize parasitic drag and all of the frictional components of the rolling system it could be incredibly efficient when compared to a ship pushing some 4000 square feet (400 square meters) of cross sectional area of water at 20 miles per hour.
And, as I have said multiple times, this isn't really solely about pure energy efficiency as much as a forward looking idea to that hopes to deal with the grotesque level of environmental pollution these ships produce as well as what might happen over the next 100 or 200 years with fossil fuels. One really has to start looking in at least a 50 to 100 year time scale to understand that what we are doing today is not sustainable in any way at all. To some extent, arguing the finer points of how much one displaces vs. the other and whether one solution is a few percent more efficient than the other is to miss the point.
The camry example was just an illustration of the power relationship of something moving through water. Nothing more than that.
The comparison of a container ship with 5,000 TEU (2,500 40 foot containers) vs. a train is, of course, different. And, of course, it isn't as simple as looking at cross-sectional area. That would be a gross oversimplification. Sometimes you have to assume that a cow is a uniform sphere of milk just to start to have some numbers to talk about.
Imagine a train design to carry containers at 200 miles per hour. Single file. So, now, the cross sectional area is that of a single container, which is very small. If the train is designed to minimize parasitic drag and all of the frictional components of the rolling system it could be incredibly efficient when compared to a ship pushing some 4000 square feet (400 square meters) of cross sectional area of water at 20 miles per hour.
And, as I have said multiple times, this isn't really solely about pure energy efficiency as much as a forward looking idea to that hopes to deal with the grotesque level of environmental pollution these ships produce as well as what might happen over the next 100 or 200 years with fossil fuels. One really has to start looking in at least a 50 to 100 year time scale to understand that what we are doing today is not sustainable in any way at all. To some extent, arguing the finer points of how much one displaces vs. the other and whether one solution is a few percent more efficient than the other is to miss the point.
I'll go ahead and send you a link to the data.