Hog

Hog
Since my last cast we have been trying to imagine Totem’s original lines.  Since they burned down in a fire all we have are the lines off a model thats at Mystic Seaport.  We also want to rate as a 6 Meter so we have benchmarks we have to rediscover as well, such as water line length, weight, sail aria amongst other measurements.  This has left us with some grey aria, hmmm.  Luckily in the middle of the bewilderment we unearthed some old race measurements from her past, thanx Mystic.
First it is possible that the bottom profile, seen in the photo at the top of the page,  may very well be the original and all the hogging, sagging, that appears to be happening is only in the sheer, the deck line profile.  The previous ratings also state that she is now 6 inches shorter than her rated length.
This is where Jacob has been instrumental in discovering two paths.
From Jacob August 3, 2007
Option 1:  The interesting part is that the rated length is shorter under the current plan to jack the transom up to get more sheer aft.  If we rate as is we could add 1sq m of sail area or about 10 sq ft or 2% of total sail area.  This presumably would be a faster boat, definitely downwind.   Recap, versus original we would have same waterline length and weight, shorter rated length which gives us more actual and rated sail area.
Option 2:  In order to match the waterline length and rated length from 1937 we would not do any jacking of the transom.  This would leave the very droopy aft sheer line, so to remedy this we would need to build up a sheer on the existing to get the desired shape we want.  It would be flatter aft than what we are currently looking at doing but still have some shape.  Also as part 2 of this option we could add on to the overall length of the boat for a longer overhang.  Recap, this would most closely match the more probable aesthetic of the original boat.  We would be matching the waterline length, displacement, rated length and sail area, as well as the probable sheer line.
The road splits.  These boats were historically always under transformation and optimization so to end up with more sail aria than 1937 might be warranted.   The 1937 boat has an improved keel over the original 1930 build.  That said there is this nagging to create a restoration that embraces the historical boat of 1937 for the sake of history.
From Jacob August 6, 1AM
Hi Jesse,
I am going to Concordia tomorrow and will try and call you on my way.  The speed comparison was not to revealing.  Basically the original profile with the longer rated length was faster upwind by about 5 secs/mile in all conditions except 6kts and less of true wind (very light).
Downwind more sail area was faster at speeds under 8 kts of wind, 10kts and higher the boats were the same to longer boat being a little faster.  Therefore around the course more sail area won by about 6 seconds/mile in the very light and then it was the same at 8kts and she lost in everything over 10kts by about 4-6 seconds/mile.  Raw text of results attached (higher, positive seconds is slower).
It is hard to base a decision on performance, one can say both boats are very fast ( I also ran [“another 6 meter”] in the race and [she] clean her clock by 20-60 secs/mile around the course!!!).   There is very little in this , but if you were to go with hard numbers the longer length is a hair faster (and 6s/m is the minimum for a decision), suggesting we should not raise the profile, but fix the sheer to our liking.
Talk tomorrow,
Jacob
There it is, before the use of computers and tank testing, Bill Luders designed a very fast boat, Totem.

Thursday, August 9, 2007

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