The unusual physics of wind blown traveling devices

The sailing yacht is the only means of transport that uses an endlesss supply of free energy to carry us anywhere there is water sufficient to float our hulls. More than that, sailing boats appear to be following a trajectory of increasing efficiency that is not shared by any other transportation device. Can we make a case that sailing yachts are unique in our physical world for the way their efficiency scales over time?

Trimaran Macif, world record holder for fastest solo navigation of the globe 2017
Trimaran Macif, world record holder for fastest solo navigation of the globe 2017

We all know about  Moore's law, sometimes referred to as the law of exponential growth. Processor chips double in efficiency and halve in cost every 18 to 24 months. They've been doing this for over 50 years and they're not finished doing it yet.

Author and tech head supreme, Kevin Kelly, provides us with a list of 21 small technologies that follow a similar trajectory to Moore's law. 

Among the technologies plotted are Digital Cameras plotted by pixels per dollar, DNA sequencing measured in dollars per pair, CPU power consumption in watts per square centimeter, and hard drive storage in Gigabytes per dollar.

Bit of a trend here? Kelly goes on to say that this effect really only applies to small technologies. 

 

They become more efficient and cheaper as they get smaller. It doesn't apply to big things like ships, buses, space stations and aircraft.

Why?

Because as these things get bigger they require more energy, not less. And energy sources like batteries and solar panels don't increase their output exponentially as the technology advances.  They only increase linearly.

Gordon Moore  jokes that if the technology of air travel experienced the same kind of progress as Intel chips, a modern day commercial aircraft would cost $500, circle the earth in 20 minutes, and only use five gallons of fuel for the trip. However the plane would only be the size of a shoe box.

 

 


The rate at which the efficiency of small things is doubling


Digital Camera  

RAM 

DNA sequencing Dollar per pair 18

Wireless 

Hard Drive Storage 

 

pixels per dollar

megabytes per dollar 

dollars per pair

Bits per second 

Gig per dollar 

12 months

16 months

18 months

12 months

20 months



Gordon Moore developed his theory of exponential growth in the increasing efficiency of processor chips over time by plotting just five points on a chart and then projecting a straight line into the future.

The progress in chip technology and the associated reduction in cost has followed the same curve for over 50 years at this point in time.


We can demonstrate that small technologies get cheaper/faster/more efficient over time at a surprisingly consistent and predictable rate (Moores Law). We can demonstrate that the same does not apply to large technologies 


So what about sailing boats? The energy source if free, however we have to concede that we're not going to have a lot of influence over the exact characteristics of the energy source at any given time. 

That issue aside is it possible we can make the sailing boats go faster and cost less over time like Kevin Kelly's small technologies?

If that it possible then sailing boats would be the only form of transport available to humans that follows such a trajectory.

 

How can we measure the increasing efficiency of sailboat performance? For one thing we can take a look at times for record breaking circumnavigations and compare that to the maximum speed of cars over the same time frame.

Can we make the case that sailing boats are a unique transportation device not governed by the current trajectory of increasing energy requirements for increasing size or increasing efficiency in the same way that other large objects are?




The chart above compares the increasing efficiency of sailing yachts as measured by elapsed times, compared with the top speed of motor cars over the same 43 year period. 

The area chart above in dark green plots the circumnavigation times for 8 multihulls sailed single handed starting with Manureva in 1973-74 the bottom and finally with Macif's record breaking run of 42 days and 16 hours in 2017

The lighter green bar chart measures the maximum speed of cars measured over the same time period..

SOLO AROUND THE WORLD RECORD BREAKERS

Macif 2017 42 days, 16 hours, 40 minutes (red square at the top)

Sodebo Ultim'2016 49 days, 3 hours, 4 minutes

Idec 2 2007-8 57 days, 6 hours, 23 minutes 

 B&Q-Castorama 2004-5 71 days 14 hours, 18 minutes 

Idec 2003-4 72 days 22 hours 54 minutes

 Un Autre Regard 1988-89 125 days 19 hours 32 minutes

 Kriter Brut de Brut 1986-87 129d 19h 17m

 Manureva 129 days 19 hours 57 minutes 1973-74



 

 From these numbers we can say that while cars only improved their top speed by 165%, sailing yachts quadrupled their performance.


Manureva; the first modern multihull to make a solo navigation, and for that matter almost certainly the first multihull ever to make a circumnavigation.

In 43 years the number of days for a solo circumnavigation has been reduced by just more than one day every year to decimate Manureva's time by a factor of 4.

 

In the 43 years from 1974 to 2017 the fastest cars didn't even double in performance. The Lamborghini Countach clocked 288 km/hr in 1974 while the Koenigsegg Agira RS clocked 447km/hr; just 1.65 times faster than the Countach.

 

 

From these numbers we can say that while cars only improved their top speed by 165%, sailing yachts quadrupled their performance.


Record Breaking Cars


Healy Elliot
Healy Elliot
Lamborghini Countach
Lamborghini Countach
Ruff CTR
Ruff CTR
Koenigsegg Agira RS
Koenigsegg Agira RS

Healy Elliot

104 MPH in 1946

Lamborghini Countach

182 MPH in 1972

Ruff CTR

212 MPH in 1987

Koenigsegg Agira RS

278 MPH in 2017



Even greater gains in efficiency for sailing boats are in the wings

For sailing boats there are three ways we can further improve performance without increasing size.

Foils, Planing Using new materials, better engineering, better rig and sail design to improve the power to weight ratio.

The first two are unique in their availability to sailing yachts, the third could be applied to any form of transport device.

 

There is a fourth factor that is emerging now, and that is the ability to generate and store energy while sailing. This is significant because it compensates sailing yachts for the times when the wind is not cooperating and it has the potential to further widen the gap between sail boats and other forms of transport.


Why regeneration technology and energy storage will further change the game

The primary reason why sail boats are only used for pleasure is the unreliable nature of the wind. However the technologies to capture and store energy from the wind are improving rapidly and we are very close to having systems that will reliably and efficiently propel our yachts when the wind is not favorable.

 

Lithium metal-based batteries have the potential to turn the battery industry upside down. With the theoretically ultra-high capacity of lithium metal used by itself, this new type of battery could power everything from personal devices to cars.

 

You might argue that improved battery technology will benefit other forms of transport technology as well, and this is true. However sailing vessels have a lot more to gain.

 

Increased battery storage capacity will do little to change traveling times or top speed of motor vehicles. The exception is that it will reduce the need to recharge as often or for so long.

On the other hand improved electric power on a sailing vessel will increasingly compensate for periods of no wind or contrary wind and further increase the rate of improvement in efficiency of sailing vessels compared to other modes of transport.

 

The new Oceanvolt ServoProp variable pitch sail drive is one of the most recent developments in technology. It facilitates both the capture of wind energy, in this case indirectly but efficiently through the motion of the vessel, and the propulsion of the vessel.

 

 

The ServoProp uses software to adjusts the pitch of the sail drive propeller blades automatically so that the power generation and power output are optimal for a range of sailing conditions. 

The Norwegian Vindskip design from Lade AS
The Norwegian Vindskip design from Lade AS

The Norwegian Vindskip design from Lade AS uses a specially shaped hull to capture the wind and convert it into forward motion.

Marine engineers at Lade AS in Norway have designed a freighter with a hull shaped to harness the power of the wind, letting the ship save 60% on fuel costs while emitting 80% fewer emissions.

ServoProp uses software to automatically adjust propellor pitch for propulsion and regeneration.
ServoProp uses software to automatically adjust propellor pitch for propulsion and regeneration.