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Old 03-14-2010
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Quote:
Originally Posted by wannabe4 View Post
Ladies and gentlemen, I once again call on the collective wisdom of this forum.

I am interested in a discussion of the performance of a full keeled boat with forefoot cutaway and a cutter rig. Specifically, how well upwind does a Tayana 37 perform? Besides the fact that it has a wide shroud why does the full keel inhibit upwind pointing ability?


For those of you with experience sailing on a 1980's era Tayana 37 what do you think of its upwind performance? Speed?

Thanks in advance to all who respond!!
Answer to above: Cutters (full keel cutters) usually have dynamic RIG TENSION problems, that if not recognized and corrected/adjusted on-the-fly will/often result in abysmal 'performance', especially 'pointing ability'. Once those rig tension anomalies are considered and corrected/adjusted a full keel boat 'can' come somewhat close (but not 'that' close) to the 'performance' of a simple-rigged sloop.

I have a Ty37 which I club race in PHRF and also do a bit a distance cruising.
You really need to define more what you mean by 'performance' (ala a Ty37).

A 'plain vanilla' Ty37 (PHRF-NE @ 174) will be somewhat a dog for round the buoys racing if not 'enhanced' by hull fairing, slick bottom paint, keel leading edge reshaping, comprehensive change of rigging tensions, change to 'race-cut' (flat luff entry) sails, feathering prop., etc.

Detractive to (racing) performance is an ungainly and extremely heavy (aluminum) mast (tender and s-l-o-w rolling period), a mast that is erroneously placed ~20" too far aft. These (1975) design and 'yard execution' errors can be somewhat easily remedied: relocation of position of maximum draft in the mainsail to be 15-18" 'more forward' than 'normal' sail design - also necessitating a 'more flat' / less maximum draft in a newly cut sail. The mast plan was originally designed for a substantial rake. With the apparent boo-boos, even with 'cruising-cut' sails all one has to do is bring the mast perfectly 'straight up' / perpendicular and apply hard halyard tension to force the PoMxDrft forward in the mainsail to easily attain a neutral helm. Without such 'mods', a plain vanilla Ty37 will exhibit a LOT of weather helm and keel skid; with the 'mods' you can have a neutral or 'dead fish' helm.

The second performance 'issue' in the Ty37, and most 'cutters' / 'double headed' rigs, is the eternal/infernal 'load sharing' between the two forward stays (headstay - jib; forestay - foreSTAYs'l). Without adequate means to control the variable stay tensions (by runners, differential tensioner on the forestay) the shape of the headsail/genoa 'can' become 'slack'. What causes the 'differential tensions' is typically the genoa 'loads up' and such load 'transfers to the forestay (where the staysail lives) - this dynamically 'unloads' the headstay tension and causes the headsail luff to "fall way off to leeward, increases draaft, and causes draft-aft in the headsail". Slackness in the forestay will result in diminished pointing ability, aggressive heeling, the keel skidding off to leeward, ... and the boat becoming a 'pig' when beating.
There is a very steep learning curve for 'sloop drivers' when they start sailing 'cutters'.
The corrective options are to slack down the forestay tension to less than 5-10% rig tension when beating, applying thin draft stripe along the luff to ensure that the 'luff hollow' that the sailmaker cut into the genoa/jib remains under control and MATCHES the normal sag in the headstay. The slacking down on the forestay will transfer tension to the headstay - allowing the headstay to 'match' the inbuilt 'curve' at the luff of the headsail. Early Island Packets had an on-the-fly forestay tension control but since that system was all-wire probably had many failures due to the wire turning over small sheeves, modern ultra-high strength line could allow this concept an easy solution to the variable tension sharing of the forward stays.

Note: the only aerodynamicaly correct treatise ever written for use of a STAYSAIL (under a jib/genoa): http://www.arvelgentry.com/magaz/The...e_Head_Rig.pdf If you follow the advice given in this article, it will pay dividends in staysail performance.
FORGET totally such erroneous concepts as 'slot effect' when sailing with a staysail.

Once a Ty37 is set up as above, I find that sometimes I can get LIFT towards windward out of the keel, as one can experience out of a high aspect fin. I used to win a lot of 'pewter' with my Ty37 in 'club races'.
Typically, I can point (not pinch) @ ~85°M, without the above one will probably get only 100°M. Depending on the windstrength and seastate I usually barberhaul the jib/genoa sheets. Staysail is flown in 'anything over 5 kts.
You really need a clubfoot (or Hoyt-Boom) if you want any 'performance' out of the staysail; otherwise, you will have a 'badly twisted' staysail on anything other than a beat.
My WAG estimate is that my current config. gets me to about 165 PHRF.

I club-race PHRF and cruise from the Canadian Maritimes to 'da islands'. Ive been through F9 stuff a few times - and will make positive comments of the 'performance' of the Ty37 in 'stink' conditions (even with a full 'cruising load'). With this boat set up for 'performance', I often sail (well) during those 'light' conditions when most others are 'motoring'.

If I had it to do all over again, Id choose a Perryboat with a modified fin (Valiant, Tashiba, Passport, etc.) and with 'split underbody' ... for better 'performance'. A Ty37, IMHO, is well 'over-canvassed' - having all the sail area one needs to keep her 'up near hull-speed'.

Hope this helps.
:-)
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