Old as Dirt!
Join Date: Nov 2008
Location: Tampa Bay Area
Thanked 99 Times in 94 Posts
Rep Power: 6
Re: Recognize this furler?
Originally Posted by chartscharts
Thanks for the photo assist, mitiempo!
Thanks for the replies everyone and svHyLyte for the identification. I found this based on that: Stearn Twinstay One / Dynafurl One
Looks like I have a Stearn Twinstay One (or maybe the Dynafurl) that likely came with the original boat.
You said, "one cannot reef with it as one can the more modern equipment." May I please ask which of the following you mean by "cannot reef" ?
1. Partially furling results in a poor sail shape and poor sailing performance as a result.
2. Partially furling results in an unsafe condition that may cause the rig to fail?
3. Something else?
My big sail comes in handy in the often light airs of San Diego. On occasion, though, I've been overpowered and rolling it up a bit has really helped. I'm interested in knowing whether that's an unsafe idea, or just one that results in inefficient sail shape.
The "Twinstay" is simply the foil, alone. The Dynafurl included the drum, swivel and foil. The foil is not symmetrical about its longitudinal axis like wire rope, and does not do well with loads applied normal to the major, transverse axis. With the sail unfurled, the leading edge of the foil virtually always aligns itself with the sail and apparent wind so loading is always normal to the minor transverse axis. Partially furled, it can be loaded transverse to the major axis and become subject to fatigue weakening. Although I have never personally seen a Twinstay fail, "in the day" there were reports that some had (fortunately, the halyard load on the luff of the sail would continue to support the mast although getting the sail down would become problematic). I suppose if you were attentive to where the tack fittings on the drum were located you could get away with a partial furl but I wouldn't make a practice of it and, absent a fairly bulky foam or rope luff, the set of the sail would be terrible.
The Cal 29 will sail quite nicely bald headed or bald headed with one or two reefs in the main (BTDT). We started out with our boat in San Francisco but took her south in about '85. In SoCal we sailed out of Alamitos Bay Yacht Club in Long Beach until '92 and covered everywhere from Santa Barbara to Ensenada without difficulty with numerous trips to Catalina. We didn't care for San Diego all that much as the Bay always seemed too crowded (it was a mad house on weekends) but we did love visiting San Diego YC and the watering holes/restaurants on Treasure Island. All the time utilizing the Dynafurl. We finally brought the boat back to south Florida in '92 and relied on the old gear until '99-2000 by which time it was pretty beaten up (after 24 years of hard use and less than ideal maintenance I have to admit.) We got a very good deal on a Harken system from JSI when we re-rigged the boat during the refit and so took it. I'll bet $10 bucks that our old Dynafurl is still laying by the bottom of the fence in our boatyard and, with a little effort, might yet be put back in commission.
If your furling is stiff/cranky, by all means buy a spares kit (once) from Rig-Rite. But, in my view, that vendor is unnecessarily expensive so once you've gotten the kit, take it over to NAPA and get the catalog numbers for matching bearings there and pick up a few for your spares locker. Unless you are insistent on partial furling, the Dynafurl will/can last virtually last forever.
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."
Last edited by svHyLyte; 12-05-2013 at 08:57 AM.
Reason: correct typo