In this post I do the unit conversion and the math for our forum readers.
The statements in this thread do not convey my personal take on the issue in any way.
With kevlar reinforcing the BARE mast section weighs 8.6kgs for a 25' length section
F14 carbon mast (25 feet long = 7.62 mtr) :
8.6 kg / (25 * 0.3048) = 8.6 kg / 7.62 mtr = 1.129 kg / mtr
If this particular bare mast were 8.5 mtr long (F16) then it would weight ; 8.5 mtr * 1.129 kg = 9.593 kg
Using the earlier stated rule of thumb : tipweight = 1/2 * bare mast section weight + 0.75 results in.
1/2 * 9.593 + 0.75 = 5.547 kg tipweight.
In my calculations I found that the fittings themselfs add 2.64 kg to the mast and 0.827 kg tipweight. If lightweight spreader arms are fitted (proctors are relatively heavy) then numbers are 2.40 kg and 0.75 kg. Hence the use of the 0.75 number earlier.
With this averaged info we arrive at a F16 carbon mast, based on the F14 specs, that have an overall weight of about 9.593 kg + 2.40 kg = 11.993 kg. = say 12 kg overall. And this EXCLUDES the weight from the halyards and trapezelines !
These halyards (main and spi) are about 200 grams = 0.2 kg per 16 meter. And so these add 0.2kg to the tipweight while adding 0.40 kg to the whole mast. 4 high tension line trapeze lines are combined 0.2 grams and add 60 grams = 0.06 kg to the tipweight. These are pretty much neglectable in the overall picture.
So our estimate of the F16 carbon mast based on the F14 carbon mast comes out at :
Overall weight = 9.593 + 2.400 + 0.400 + 0.200 = 12.593 kg = say 12.5 kg
Tipweight = 5.547 kg + 0.200 + 0.060 = 5.807 kg = say 5.8 kg
As a comparison : the Alu superwing (Taipan, Blade, Viper) mast has the officially measured (averaged) specs :
Overall weight : 18.0 kg (and 20 kg including the 4 mm thick stainless steel standing rigging)
Tipweight : 8.25 kg (excluding the standing rigging)
At 85-90 kg dry body weight I have never encountered problems righting my F16 (which is 121.8 kg ready-to-sail when fully sloop rigged)
The Stealth specs are given in the post by John Pierce earlier.
Also note that Darryl wrote :
... for a section for an F16 the per metre weight would probably increase slightly as we would modify the ratios of the laminates ...
Also note that some weight savings can be had by using very lightweight fittings and a push up mainsail. But also note that these change will not alter the calculated tipweight much as the above example shows.
Interestingly enough these calcs mirror closely the calcs that supported the 6.00 kg tipweight rules choice in the past.
Wouter
