Here's some ingenious engineering
which may well move ocean shipping back into the sail era.
A German shipping company is this year outfitting a newly-constructed heavy cargo
freighter (the Beluga Skysail) with another recently developed German technology
termed skysail.
The skysail is a large aerodynamic kite (shaped like a paraglider) which automatically
deploys and retrieves (via winch) from a forecastle mooring mast and operates
on a tether at 100-300 meters above its ship at altitudes where ocean winds are
strongest and most dependable.
The kite is computer controlled to consort wind speed and direction with ship
course, engine usage, and speed through the water.
The kite varies its relative deployment to its ship via the tether's connection
with a rail system running along the ship's hull.
The kite can also vary its own configuration to increase or decrease wind propulsion
input.
The skysail system causes no ship heeling.
It can operate up to 50 degrees to the prevailing wind (which, not being a sailor,
I suspect means it can propel a ship on a straight course using any wind from
any direction save 100 of the 360 degrees relative to the ship's course).
The whole system is hands off and 100% operable by button pushers on a ship's
bridge
It can apparently reduce ocean shipping fuel usage by up to 35%.
This is significant because ocean shipping annually uses 2 billion barrels of
oil (5.5 million barrels per day).
Here's a link to the website of the skysail system's German manufacturer, which
contains an informative video you can watch with Windows media player:
http://www.skysails.info/index.php?L=1
After this year, we may be seeing sailing (well, partially sailing) ships again.