Please see my profile, photo albums, Puffin where I have pasted the to scale drawings for my latest design for the sib-lim challenge.

I have rushed the design a bit, as I only got my drawing board back a couple of weeks ago, so my drafting is not the best and the design drawings are not as complete as I would have liked, but it should be understandable. I am also working to get as much done on other projects as I can before I leave for Australia next Tuesday.

The design is very similar to the sketches I posted earlier but is now to scale, and represents a design more angled towards a comfortable live aboard rather than just a sailboat with accommodation. The sail area has reduced a bit but otherwise it has remained very much the same, but with a bit more detail. I have added an option for a small dog house (which I know you do not like on principle) which I think will add to the usability of the cockpit area, especially in the non summer seasons, when it will allow more protection to the hatch and also some shelter from the seas coming over the bow (maybe you could think of it as a large pram hood??). It also provides a sheeting arch on its rear edge which keeps all of the ropes out of the cockpit when tacking or gybeing, which I think you will like.  The small mizzen also acts as a self steering with a rotating mast, fixed boom and a tiller arm forward through the transom. There is a split sleeve and tightening screw so that the mast can rotate to the wind and then be locked in position. This can be hooked up to the tiller and should be ok as a direct wind vane to tiller steering, similar to that developed by Chichester for Gypsy Moth in her OSTAR races. It can also be locked in position to help keep the bow to the wind when at anchor.

    The interior has a chain locker forward that drains above the waterline and the sloping floor should prevent chain pile ups. There is a storage locker below this. The double bunk in the forward cabin is six feet six inches long, five feet wide at the head and over three feet at the foot.  A hanging locker and some shelves are located on the starboard side. There are bookshelves above the bed to port. Steps on the bulkhead access the overhead skylight/hatch.

    Aft of this is the composting head to port, shower tray for use of a solar shower, and a wash hand basin to starboard. The doors could be replaced by curtains if desired and the wash hand basin could become a clothes locker if you wanted. 

    The main cabin has a raised dinette to port with a fold up chart table, and quarter berth aft of it for your guests. Storage for you water jugs is under the raised floor and there is a wine locker under the table. To starboard is the wood burning stove next to the forward bulkhead and the galley aft of that, with a single sink and a two burner with oven stove. A wet locker is provided just inside the companionway to starboard and two drawers allowing for easy access to the storage spaces below the cockpit sole and the cockpit locker to starboard.

    In the cockpit the port side seat forms the deck above the quarter berth and the fuel storage locker aft. The outboard well is offset as far to port as it will go to allow space for some cockpit floor to starboard. I have shown a Yamaha four stroke 9.9 HP.,short shaft motor which appears to fit well, however if you decide to build make sure that you line up the motor before you build the well, so that you make sure that it fits!! There is a cockpit locker to starboard, as well as a second fuel locker open to the cockpit, the floor is at the cockpit sole level, so it is not too deep for good access and can have a drain into the cockpit to drain out any water that may leak through the hatch. There are lockers outboard in the coamings accessed by hatches in the seat backs

    The rig is a standard Hasler Mcleod shape with a triple fan, a five panel lower section and a six part sheet. She is intended to have camber per Arnie's method. She has an aspect ratio of 2.1 which is on the low end of high aspect, this means that the mast is only 32 feet long and should be reasonably easy to lower as it is mounted in a tabernacle attached to the foredeck and forward cabin bulkhead. At the moment the lead is a bit low at 13 percent but I will correct that by moving the mast and the forward cabin bulkhead approximately 12 inches forward, this should give about 17 percent lead. The rig is designed to have a yard parrell, batten parrells, fixed luff parrells, topping lifts, a yard lift and a boom parrell to stop the boom moving forwards. So only three lines to handle normally.

     Anyway that is my latest contribution to the sib-lim challenge, have a good look at it and let me know what you think.

Hampus Mattsson wrote:

Click on the image to open it in a separate tab, then right click and save it to your hard drive, then you can enlarge and zoom as much as you like. The resolution is enough for the drawings to be printed on A1 size paper with no quality loss.

My carved-in-stone main rule about the need for THP, LHP, HKP, long or short batten parrels and wotnot, goes like this:

There is no carved-in-stone main rule
about
the need for parrels on a JR.

Factors like aspect ratio, sheet angle (steepness), sailplan type and how slippery the mast and ropes are, are important factors when it comes to what works and what doesn’t. Generally, I find that sails with higher AR (2.0+) are more forgiving than sails of low AR. I seem to have settled on the use of five running lines on may sails between AR= 1.87 and 2.15, at least:

• ·         Halyard (attached about 5% aft of the middle of the yard) 1-, 3- or 5-part

• ·         Sheet, 3-part (plus winch if necessary)

• ·         Throat hauling parrel, THP

• ·         Yard hauling parrel, YHP

• ·         Fan-up preventer FUP

With half-long batten parrels this lets me hoist and lower the sail without problems with friction against the mast.

I still use Hong Kong parrels. Although they see little load now that I use the THP, they are useful for fin-tuning the setting to keep away diagonal creases.

David Tyler wrote below:

«The beauty of the junk rig is that there's usually more than one way of doing things.”

I agree 100%.

Paul JT wrote:

«What I'm saying is that the amount of balance you have in the sail dictates the yard angle. Not looks or some arbitrary formula. You can prove this to yourself very quickly by making a stick and string model.»

This is actually how I landed on 70° yards as it lets me vary the sail balance between 5 and 15%.

Cheers, Arne

PS: I had a short sail in Frøken Sørensen with a mate today (on our Constitution Day!), the 3^rd since Thursday. It strikes me every time, how quick it is to rig the sail bundle and get the boat sailing again after launching and erecting the mast. And the sail sets like magic, every time...

David Tyler wrote:

Well, yes, Paul, that's true within a certain range of yard angles and supposing that you only have the THP to pull the luff aft and peak up the yard. The logic breaks down at high yard angles, where even if the halyard is close to the mast, the loads on the YHP and THP are heavy. 

The beauty of the junk rig is that there's usually more than one way of doing things. It's been a revelation to me, over the past few weeks, to rediscover how good short batten parrels are, so long as they are attached at the right place on the batten (and so long as they are made from slippery, low stretch material, ie, Dyneema) (I also have a short "batten parrel" across the yard, to stop it drifting forward. 

I have a large angle between halyard and mast, I have a very low-angled yard and almost no balance area - and yet the LHP is redundant and I've taken it off. I never had to think about adding a THP. And the sail sets crease-free,without any attention or tweaking from me. And it goes up and down without problems. 

What I can say, is that I have built two "van Loan" style rigs to date and my observations do hold for that style of rig. 

BTW: I do think that a lot of what you are seeing with your own rig could well be due to the short batten parrels. I'll definitely give them a trail as soon as I can spare the time.

David Tyler wrote:

Annie and I have been discussing the sailplan, whether the sail should be of medium or high AR, and whether a tabernacle is possible or desirable. There's a lot of personal choice involved here: I don't think I'd want to say that either sail is "better" than the other. 

This is what I have done on LC and it is what makes the loads on the THP & LHP's low. It's also why the yard angle on the foresail is different from that of the mainsail.

What I'm saying is that the amount of balance you have in the sail dictates the yard angle. Not looks or some arbitrary formula. You can prove this to yourself very quickly by making a stick and string model. 

I've also found (at least on LC) that moving the attachment point of the standing part (in the case of a three part purchase) of the halyard 10% of the yard length aft of the center halyard block attachment just about removes any remaining load on the THP. I think I may no longer need a THP, however I have not yet removed it.