Does anybody have tried or considered to improve Weekender poor upwind performances by chine runners?
I'd like to try it, can someone give me some advices (such as lenght, location, thickness etc.)?
Gianluigi
Chnie runners will not do much for a Weekender, especially windward performance. Explaining how and why they work and to what degree and on what type of hulls would take too long, but suffice it to say that runners are a design "crutch" very rarely used on, but on certain hull shapes to offer marginal abilities, some modest enhancement.
Windward ability is a function of several factors, though aspect ratio in both the rig and appendages make the biggest affect on pointing angles. Weekender's very low aspect ratios make windward preformance just a pipe dream, realistically as would any boat with similar physical attributes.
Windward is only one point of sail, all the rest the weekender does well for it's size. If it takes two more tacks to get around that point, why, that's just more sailing
 Those skinny high masts and main sails need loads of other sails for every other point to get best performance.
With huge roach, square top mains this is less true then it once was. The last A/C campaign proved, you can carry all that you need to run at maximum speed in just a single sail, but bring your purse and your first born.
It seems like all I ever do is go upwind. When I don't have a particular destination in mind, I just sail upwind from the dock so that when the wind dies (Which it does at seven o'clock sharp every evening on Great Slave Lake), I can use the remains of the wind to hopefully drop back down to my dock. Sometimes I end up rowing. I wish there could be one time that I'm going somewhere, it's downwind, and I don't need to come back. (Hopefully this is a good description of the last thing we all do)
The fact that I can go upwind at all in something I made in my garage makes me happy. I guess I would sing a different tune if I actually had to be somewhere upwind, but the fact is, Yellowknife is the only place anyone would WANT to be in the NWT, so no-one is complaining if it takes a long time to leave. Maybe that's why there are so many weekenders here.
It sounds to me like you need to modify your point of view, Gianluigi, not your boat! Â
The hard chines on the Weekender to act a bit like runners already. I've read but not had much chance to attempt - that in light winds sitting on the leeward side and creating some heel dramatically improves windward ability.
The chines on the a flat bottom hull form don't act anything like runners. The hull sides bleed off pressure as quickly as it builds, so no advantage to burying it. In fact, additional chine bury just creates vorticity drag along the chine, which is a speed robber. Forcing the chine down depends on where you do it, to be of any benefit to windward. If you force the chine down by hiking out aft in the cockpit, then the boat will bear off, not head up. If you hike out at the forward end of the cockpit (very forward end) so you get the bow to bury more, because you're forward of the CB, then the tendency to round will increase from a larger lee surge wave formation.
Chine runners are a complicated subject that I suspect most here wouldn't understand. Think of them as effectively end plate technology for deep belly boats. This is a dramatic over simplification, but easy enough to visualize. The profile of Weekender's hull precludes their use, which is a hydrodynamic gimmick anyway.
If I understand the complexity of this issue it sounds a lot like adding an airfoil to a garden tractor. You might get styling points but it won't add stability on a side hill. Talking standard garden tractors not something someone has dropped a V8 into so they can win at the drag strip.
Hey, don't be picking on my garden tractor. I've got a home made cold air induction pack, redirected cooling, a freer flowing, larger bore exhaust and a ram air intake tube. The cooling changes were a mater of course, needing to replace engines too frequently here in Florida's heat. I was only getting 1,500 hours out of a typical 16 - 18 HP air cooled L head. With the cooling changes I can run them until they break something. The intake and exhaust modifications let me use a 12 HP for a 14 HP as it opens up the engine's breathing, which is usually fairly restrictive in a garden tractor. As a rule, I get about 30% to 40% more power and 200% longer life with these changes.
I bet your garden tractor doesn't have a "shaker" style hood scoop, like mine does.
The runner issue is a fair bit simpler, they are a marginal attribute and only work on certain types of hulls, which Weekender isn't one of. Bolger employed them on a very small percentage of his small boat designs. He also openly admitted to their effectiveness compared to other types of appendages. I have to admit, I wasn't a fan of his "box" boats, but I do miss his frank evaluations and clever use of engineering and hydrodynamics.
Those intake and exhaust modifications I would be very interested in. I have a nice little John Deere riding mower that I routinely use to pull a trailer. I have 10 acres, with lots of hill areas, and use it to haul fence materials and a weed sprayer around. Any improvement would be nice. When I was young, 25ish so about 25 years ago, I knew guys that had 5 and 8 horse garden tractors that had rototillers attached. The tractor motor ran the tiller and the tractor. They did a faily good job if the ground had been previously broken. Now days my 19 horse garden tractor can't handle a tiller? I realize they measure horse power differently these days but still I wonder why the loss of power and ability? I use to think it was the down grading of gasoline but it has to be more then that.
About 40 years ago gasoline was much higher rated then today. I worked for a Philips 66 station and their premium was 106 octane. It was in Minnesota and all the gas burning dragsters would stop in a buy Philips 66 gas on their way to the strip. In those days regular was 88 octane and premium was always close to 100 octane. Now days gas producers proudly claim their premium is 88 octane.