Going to regatta I had a clear plan in mind as the weather forecasts was also black and white. Both racing days were supposed to be sailed in a very strong breeze gusting up to 30kts on day one and decreasing to 24 on Sunday. -4C in the night and slightly above 0 during the day. So very windy and hard. And bumpy. Already in Gdansk I decided to prepare my stiff setup: use a very stiff mast and stiff plank. I knew I can squeeze impressive speed out of this combination with help of my 92kg.
In my practice sailing in Żnin I was testing two full carbon masts. One each day. Both seem to be on a soft end of the range. My feeling was that my plank has a lot to do with how the mast performs. When I studied my action cam recordings I felt I need to make dynamic load measurements of the plank. This measurement was done last time long time ago so I had to find all accessories hidden in the boxes covered by dust.
The setup is very simple. One important notice: apply tension/load with system built of non-stretchy materials. In my case steel cable connected to hunters’ digital scale and to dyneema wrapped around the plank.
I used headstay adjuster to precisely apply load. The laser range finder fixed to the tripod was delivering precise continuous reading of deflection. Reading of deflection was taken after every 10kg load added from 0 to 120kg.
Simple graph below shows interesting results:
Orage represents the plank that I was using for testing the masts. In some load range it is up to 10% stiffer than the other plank. I think I found the answer to my question. I should go with blue plank instead of orange.
Awaiting for new full carbon masts from Moore Bro. allowed some extra time for finetuning runner plank details. This little add-on in connection with new tang design will make plank ends look really cool.
To find out more go to Aerodynamic upgrades menu.
100 clips compilation about essential moments in making DN runner plank shot over a busy week. Feels almost unreal.
Runner plank plays a key role in developing top speed of an ice boat.