4 ms·
> "Fuel consumption can double if the vessel is traveling downstream compared to upstream," Ellingsen said. This is counterintuitive. The fact that it's easier
by ramshorns 7y ago
> "Fuel consumption can double if the vessel is traveling downstream compared to upstream," Ellingsen said.
This is counterintuitive. The fact that it's easier to make waves traveling upstream must outweigh the fact that if you're going downstream the water, you know, carries you.
- Retric 7y agoFuel consumption in boats is usually measured at some speed relative to the waters surface, not the earth.
- ebg13 7y agoThat doesn't make consumption double for "traveling upstream" vs "traveling downstream". The "traveling" part means actually getting somewhere, not treading water. If you turn off your engine entirely, you will still travel downstream and consume zero fuel. The article is about the necessary specific context for the statement to be accurate.
- ptaipale 7y agoThere's a point about fuel consumption when travelling downstream though: you can't just switch off your engine and drift downstream, because you'll run aground fairly soon. The ship needs steering, and steering needs engine power and relative speed to water.
- ptaipale 7y agoOr relative to time (litres or kilograms per hour).
- skykooler 7y agoThis relies on the surface of the water being static. In most rivers the surface flows. Indeed, there's a shear layer under the surface, so in a river these effects happen in the opposite direction.
- mhxion 7y agohas to be a typo
- lalalandland 7y agoI'm not sure if this is a typo, but you need a certain speed to be able to steer the ship. Going too slow downstream is like stalling a airplane, you lose control over it.