I quickly replied, yes, and said that I had a correlation equation in my program that accounted for the upwash. The proper sailing tests would determine the correlation constants to allow the conversion of apparent wind data to true wind conditions. This was important for correlating boat performance data and for tactical use during racing. I could tell that the sailing trials were going to be interesting!
The Kialoa III sailing trials were scheduled for December 26th through January 13. I caught a flight to St. Petersburg, Florida, on Christmas day, 1974.
This was one very impressive sailboat. She was 79' long and was equipped with the best of everything. After a quick look around, I set up my equipment in the navigation station and hooked it up to the B&G instruments to check everything out.
When I turned on my strip recorder control unit, the B&G instruments went dead! What in the world happened? I got out my multimeter and started checking things out. I soon discovered that the B&G instruments were not wired up like the boat that I had checked out in California. The B&G instruments were wired with a positive ground instead of a negative ground.
A quick call was made to B&G in New York. An engineer would fly down and get the instruments running again. In the meantime, I called Allen Sewell, who had designed my control unit electronics. Allen said that I would have to switch the power inputs to all the operational amplifiers. I got out my soldering iron and went to work. With the B&G instruments fixed, I was ready to start recording data.
Each sailing day followed a carefully planned routine. On the long motoring out to deep water, a crew meeting was held below in the galley area. Many of the crew had note pads to keep track of the day's activity. This was just like a business staff meeting. The first item was to review the work that was supposed to have been accomplished last night. The proposed list of tasks for the day were reviewed and discussed. I frequently was asked to review the data that I had taken on the previous day and make any recommendations for the day's tasks. A similar crew meeting was held each day on the way back in.
The strip recorder was only run during actual sailing tests. I would stick my head out on deck to see and hear what was going on. When they said that they had reached stable sailing conditions, I would go back to the nav station and start the recorder. I wrote notes on the strip recorder paper as it came out of the machine (sail selection, sail trim notes, compass heading, who was driving, etc.). The recorder was turned off as the crew got ready for the next sailing condition. Occasionally, I was able to spend some time on deck taking pictures (see the Photo Archives, Kialoa III Sailing Trials).
For windward work we usually collected data on one tack, then tacked the boat and collected data again. Data was frequently taken during the maneuvers in order to learn how to best tack the boat. Occasionally we would head the boat directly into the wind and slow it down in order to determine the true wind direction and speed.
Off the wind, testing primarily involved experiments with sail selection and trim, and this boat had a lot of sails! The objective here was not only to learn how to make the boat go fast, but also to gather data to fill out the speed polar plots.
Each evening I spent several hours reading the day's strip recorder tapes and loading the readings into a data sheet for analysis. I then processed the data with my hand held HP-45 calculator. This usually involved calculating the true wind speed and direction, and tacking and jibing angles. Each set of data allowed me to refine the upwash correlation constants to improve the apparent-to-true wind predictions. The flow upwash angles were higher at the lower wind speeds and decreased as the winds got higher. Needless to say, my evenings were very long in order to have the new data ready for the crew meeting on the way out the next day.
In a letter that I received after the sailing trials, Kilroy said, "I do believe that we have gained many months of knowledge of Kialoa's performance and I feel most confident of this knowledge after these trials than I did over a year of sailing Kialoa II."
A few years later, Kialoa III was in the Northwest and I was invited to crew on her in the Swiftsure Race. I was trimming the main as we neared Cape Flattery. I watched as the 15 or so crew hustled to get ready for a squall that we could see coming and thought, "How in the world is this all going to work out?." It all came out beautifully!
For more information on testing techniques go to file, Sailboat Performance Testing Techniques.pdf.
