Re: Single-Luff Spinnaker
Hi all
I remember a discussion regarding this some time ago. I believe the conclusion we came to was that Phil Bolger was talking about a foresail much more similar to a jib sail in cut and handling than to anything we tend to call a spinnaker (symmetrical or asymmetrical) these days.
Essentially I believe the name has a lot more to do with the fact of tacking it to a pole and setting it flying (as opposed to a jib which is tacked to the bow). Control lines for the pole always make sense to me. Although in this case I think there is more need of the downward control line.
The few photos included in Phil’s books showing such a sail set (I will try and remember the picture I’m thinking of) certainly gave this impression.
I see the sail cut as a jib built to be set flying (ie assuming that the luff will sag significantly). If you take the dimensions of many of the single luff spinnakers, I reckon they can be be handled pretty much like a regular jib. I don’t remember them being specified for boats with forestays, but happy to be corrected on this.
I remember a discussion regarding this some time ago. I believe the conclusion we came to was that Phil Bolger was talking about a foresail much more similar to a jib sail in cut and handling than to anything we tend to call a spinnaker (symmetrical or asymmetrical) these days.
Essentially I believe the name has a lot more to do with the fact of tacking it to a pole and setting it flying (as opposed to a jib which is tacked to the bow). Control lines for the pole always make sense to me. Although in this case I think there is more need of the downward control line.
The few photos included in Phil’s books showing such a sail set (I will try and remember the picture I’m thinking of) certainly gave this impression.
I see the sail cut as a jib built to be set flying (ie assuming that the luff will sag significantly). If you take the dimensions of many of the single luff spinnakers, I reckon they can be be handled pretty much like a regular jib. I don’t remember them being specified for boats with forestays, but happy to be corrected on this.
Sorry to dredge up this old thread but, while the previous discussion was enlightening, I'd like to get some more clarity on how the pole is rigged for this "reaching spinnaker" and how the hoist and douse are performed.
---In bolger@yahoogroups.com, <arvent@...> wrote :
My best guess is this: the pole has a pole lift and two fixed guy lines.
When you'd like to play with the spinnaker then you go forward and hook the pole to a pad eye on the front of the mast. You hoist the pole lift until the pole is horizontal. Now you go back and snug up both guy lines so the pole is "set" for the time being.
The clew of the spinnaker has two sheets like a cruising spinnaker which you lead back through your fairleads and tie them together. You now attach the halyard and tack line to the sail (which can remain in the bag with just the corners sticking out, conveniently in the Micro's forward well).
You can haul on the tack line and the halyard separately, then trim the leeward sheet and windward guy.
Racing dinghies fasten a block to the bitter end of the tack line, then lead the halyard from the head of the sail, through the halyard block at the mast head (probably lower on the Micro), back to a block at the base of the mast (like the snotter, but lower) then out to the tack line block, then back to the cockpit.
What this means is that you only pull the halyard and once the luff is tight, the tack line will pull taut from the halyard tension.
Does this arrangement match up with other people's experience? I've seen photos of people flying this sail on an AS-29 and others but haven't gotten all the details...
Apparently there are details in "100 Rigs" and a couple other books I can't get my hands on. Maybe there is some more detail in an issue of MAIB?
A
---In bolger@yahoogroups.com, <arvent@...> wrote :
This subject came up on another forum and I was wondering if anyone has tried one? Mr. Bolger has offered it on several designs including AS29 and the upgraded Micro plans. RIG 26 in his Small Boat Rigs books, specifically for a catboat rig. But have not seen much on the finer details of rigging and using one, or how much shaping it should have.
Seems to me he felt one was worth considering?
Bruce - glad to see you posting - was a bit worried about you!
Nels
Thanks for the information gentlemen.
--- In bolger@yahoogroups.com, "Arne Kverneland, Norway" wrote:
> --- In bolger@yahoogroups.com, "David" dir_cobb@ wrote:
> >
> > Nels
Actually David, the discussion began at Polysail Dave's group, where he is looking at spinnaker making:-) Not as nice as ripstop but has no requirement for a lot of seam sewing to try out. Just a bit of rounding and maybe a dart or two. I have 2 white tarps 24 X 26' I picked up for $30 to fool around with.
Believe Douglas Pollard was the owner of Wolf Trap? Maybe I could see if I can contact him and get his thoughts on rigging such as sail.
Nels
> --- In bolger@yahoogroups.com, "David" dir_cobb@ wrote:
> >
> > Nels
David,
Interesting, we seem to have similar ideas on this. Actually, inspired by PCB's spinnakers/jibs I recently drew up a lightweight jib for a friends Folkboat. From obvious reasons it could not be set on a pole.
Below is a little write-up with figures showing ho I did it. Hopefully in few weeks I can supply a couple of photos showing how it works.
Thoughts from Stavanger, Norway, as summer sets in...
Arne Kverneland
https://dl.dropboxusercontent.com/u/49284570/Other%20boat%20files/20130606%20Adding%20a%20lightweight%20jib%20to%20a%20Nordic%20Folkboat.pdf
Interesting, we seem to have similar ideas on this. Actually, inspired by PCB's spinnakers/jibs I recently drew up a lightweight jib for a friends Folkboat. From obvious reasons it could not be set on a pole.
Below is a little write-up with figures showing ho I did it. Hopefully in few weeks I can supply a couple of photos showing how it works.
Thoughts from Stavanger, Norway, as summer sets in...
Arne Kverneland
https://dl.dropboxusercontent.com/u/49284570/Other%20boat%20files/20130606%20Adding%20a%20lightweight%20jib%20to%20a%20Nordic%20Folkboat.pdf
--- Inbolger@yahoogroups.com, "David" <dir_cobb@...> wrote:
>
> Nels
>
> I get the impression from reading the books and studying plans, that the single luff spinnaker is essentially a light jib set flying rigged with its tack on a spinnaker pole rather than to a bowsprit or deck fixture. I am pretty convinced it is more a semantic issue in respect of the way the sail is rigged than something to do with the sail itself.
>
> The cover of Different Boats shows the 30' Wolftrap using one. It definitely is not a Gennaker or "balloon-type" sail by current standards. Neither does it look like a genoa shaped sail. On the Wolftrap plans PCB specifies: "Cut Spinnaker with single luff like a balloon jib set flying". What is clear is that the sail cannot require significant luff tension to stand, as it is almost invariably specified for unstayed rigs. (Neither can it be tacked in the way most jibs and staysails are).
>
> I believe I quote PCB saying "I have drawn a number of these sails and yet to see one in use." (can't find the quotation - but didn't look very hard).
>
> On a not particularly big boat, I think this is a good place to try a polytarp sail (Ohhhhh - I hear the insults) to Phils dimensions, playing somewhat with the shape. Page 141 of The Sailmakers Apprentice gives a lot of insight on sail shaping for staysails if you are prepared to take the trouble. I would round the lower half of the luff and put a dart in the tack to create some shape (in the way specified by Michalak, Polysails and others) and give it a try. You could even try a classic Bolger Leg-o-mutton polytarp guide. The cut wouldn't be quite right, but most of our home made sails (or used sails for that matter) aren't. The single luff spinnaker for AS29 is VERY close in dimensions to the Leg o mutton mainsail for Micro...
>
> Thoughts from Santiago, Chile, as winter sets in...
>
> David
>
Nels
I get the impression from reading the books and studying plans, that the single luff spinnaker is essentially a light jib set flying rigged with its tack on a spinnaker pole rather than to a bowsprit or deck fixture. I am pretty convinced it is more a semantic issue in respect of the way the sail is rigged than something to do with the sail itself.
The cover of Different Boats shows the 30' Wolftrap using one. It definitely is not a Gennaker or "balloon-type" sail by current standards. Neither does it look like a genoa shaped sail. On the Wolftrap plans PCB specifies: "Cut Spinnaker with single luff like a balloon jib set flying". What is clear is that the sail cannot require significant luff tension to stand, as it is almost invariably specified for unstayed rigs. (Neither can it be tacked in the way most jibs and staysails are).
I believe I quote PCB saying "I have drawn a number of these sails and yet to see one in use." (can't find the quotation - but didn't look very hard).
On a not particularly big boat, I think this is a good place to try a polytarp sail (Ohhhhh - I hear the insults) to Phils dimensions, playing somewhat with the shape. Page 141 of The Sailmakers Apprentice gives a lot of insight on sail shaping for staysails if you are prepared to take the trouble. I would round the lower half of the luff and put a dart in the tack to create some shape (in the way specified by Michalak, Polysails and others) and give it a try. You could even try a classic Bolger Leg-o-mutton polytarp guide. The cut wouldn't be quite right, but most of our home made sails (or used sails for that matter) aren't. The single luff spinnaker for AS29 is VERY close in dimensions to the Leg o mutton mainsail for Micro...
Thoughts from Santiago, Chile, as winter sets in...
David
I get the impression from reading the books and studying plans, that the single luff spinnaker is essentially a light jib set flying rigged with its tack on a spinnaker pole rather than to a bowsprit or deck fixture. I am pretty convinced it is more a semantic issue in respect of the way the sail is rigged than something to do with the sail itself.
The cover of Different Boats shows the 30' Wolftrap using one. It definitely is not a Gennaker or "balloon-type" sail by current standards. Neither does it look like a genoa shaped sail. On the Wolftrap plans PCB specifies: "Cut Spinnaker with single luff like a balloon jib set flying". What is clear is that the sail cannot require significant luff tension to stand, as it is almost invariably specified for unstayed rigs. (Neither can it be tacked in the way most jibs and staysails are).
I believe I quote PCB saying "I have drawn a number of these sails and yet to see one in use." (can't find the quotation - but didn't look very hard).
On a not particularly big boat, I think this is a good place to try a polytarp sail (Ohhhhh - I hear the insults) to Phils dimensions, playing somewhat with the shape. Page 141 of The Sailmakers Apprentice gives a lot of insight on sail shaping for staysails if you are prepared to take the trouble. I would round the lower half of the luff and put a dart in the tack to create some shape (in the way specified by Michalak, Polysails and others) and give it a try. You could even try a classic Bolger Leg-o-mutton polytarp guide. The cut wouldn't be quite right, but most of our home made sails (or used sails for that matter) aren't. The single luff spinnaker for AS29 is VERY close in dimensions to the Leg o mutton mainsail for Micro...
Thoughts from Santiago, Chile, as winter sets in...
David
--- Inbolger@yahoogroups.com, "prairiedog2332" <arvent@...> wrote:
>
> This subject came up on another forum and I was wondering if anyone has
> tried one? Mr. Bolger has offered it on several designs including AS29
> and the upgraded Micro plans. RIG 26 in his Small Boat Rigs books,
> specifically for a catboat rig. But have not seen much on the finer
> details of rigging and using one, or how much shaping it should have.
> Seems to me he felt one was worth considering?
> Bruce - glad to see you posting - was a bit worried about you!
>
> Nels
>
Robert,
Thanks, I am waay inland to access to used racing sails. Mainly I was wondering if anyone had tried one and how it is set up with the various control line and the spinnaker pole set-up.
Have zilch knowledge or experience with other than regular jibs let alone spinnakers, but this idea has created some interest at another group who have become aware of that option. Basically adding one to a small cat yawl.
Nels
--- In bolger@yahoogroups.com, Robert Hickey wrote:
>
> find a used 150 genoa. in light cloth. used racing sail, ideal. a sail
> worthless for racing maybe excellent for your purpose.
>
find a used 150 genoa. in light cloth. used racing sail, ideal. a sail
worthless for racing maybe excellent for your purpose.
worthless for racing maybe excellent for your purpose.
On 6/5/13, prairiedog2332 <arvent@...> wrote:
> This subject came up on another forum and I was wondering if anyone has
> tried one? Mr. Bolger has offered it on several designs including AS29
> and the upgraded Micro plans. RIG 26 in his Small Boat Rigs books,
> specifically for a catboat rig. But have not seen much on the finer
> details of rigging and using one, or how much shaping it should have.
> Seems to me he felt one was worth considering?
> Bruce - glad to see you posting - was a bit worried about you!
>
> Nels
>
This subject came up on another forum and I was wondering if anyone has tried one? Mr. Bolger has offered it on several designs including AS29 and the upgraded Micro plans. RIG 26 in his Small Boat Rigs books, specifically for a catboat rig. But have not seen much on the finer details of rigging and using one, or how much shaping it should have.
Seems to me he felt one was worth considering?
Bruce - glad to see you posting - was a bit worried about you!
Nels