shape of speed

ANOTHER LOOK AT THE SHAPE OF SPEED

The America’s Cup showcased foiling under sail; something no one can ever unsee. Foiling is the new standard. Swing keels are also a standard in the search to reduce wetted surface.

It is hard to imagine that “Charisma” was once the standard for speed under sail. Construction with aluminum lent itself to very strong boats that could be easily altered. “Charisma” was perhaps the penultimate IOR boat.

For ease of altering a boat nothing can beat aluminum. Carbon fiber is however in a class by itself for strength to weight ratio; making today’s yachts lighter and stronger than ever.

8 KNOTS VS 40 KNOTS

The giant wing sail boats of today’s America’s Cup were never even imagined when Howard Chapelle wrote his book “The Search for Speed Under Sail” in 1967. Twelve Meters and their ability to sail close to the wind were considered the apogee of yacht design. Twelve Meters sail 8 knots upwind and 8 knots downwind, no matter the wind strength. In those days the 12’s sailed a modified olympic triangle. Only one race a day because it took 3-4 hours to complete the race, sailed in an area as free of current as was practical; in an effort to make the race as fair as possible.

All of this has changed in today’s world. 40 minute races in an area with strong current, sailing at 40 knots. Regardless of your opinions about which is better; there is no turning back from the thrill of foiling.

We forget quickly how our reference of the shape of speed under sail was shaped. Last night Rich Wilson (see yesterday’s post) referred to the fact that his boat was 30% slower than the boat that ultimately won the Vendee Globe Race.

“Shadow” was Nat Herreshoff’s first design, while he was still a student at MIT; I believe. She was unbeaten over a period of years.

“Mabel” reflects a period in time when racing catboats was at fever pitch.

“Shonia” belonged to Charlie Barr, she looks pretty racy.

“Shamrock” tha America’s Cup challenger in 1903, The crew lived aboard, she was the best guess at what would be fast enough to win the Cup.