505 Rig Tuning – Craig Thompson – USA

Here’s an interesting view from Craig Thompson on tuning a 505 rig.

If you spend any time doing boat calibration/setup this weekend, I think it would be worth while to try to verify the consistency of the conventional rake measurement system. My suggestion would be to put your rig at what you think is the base setting of 25′-8″ and then measure your mast rake using the alternate method that Ethan Bixby came up with many years ago:

Without the jib hoisted, attach a tape measure to your jib halyard and hoist it until the zero mark is at the top of the boom black band. Cleat the halyard and swing it forward to the extreme upper forward corner of the bow, where stem, gunwales and deck all meet. Essentially the top forward point on the centerline of the bow. Rig tension does change this measurement slightly, but mast bend does not. Therefore it is much easier to check and relate rakes over a wide range of hulls and rigs.

Measurement range should be as follows:

Mast Rake Mast Rake
Measured Forward Measured Aft
3′ 4″ 25′ 8″
3′ 5″ 25′ 6″
3′ 6″ 25′ 3.5″
3′ 7″ 25′ 2″
3′ 8″ 25′ 1″
3′ 9″ 24′ 11″
3′ 10″ 24′ 8″
3′ 11″ 24′ 6″

My understanding is that when Glaser tuning guide was first developed with the west coast fleet, pretty much everyone was sailing a Larry Tuttle rigged Waterat which made it easy to compare setup. Now more than ever, we have people sailing many different boat types, and I think it would be an overall benefit to the class if we came up with a calibration system that was more repeatable. The standard calibration method has too many opportunities for error. Transom height, rig tension, how tight you pull the tape measure, mast bend, how high you raise the main halyard when attached to the tape measure can all significantly affect the intended reading of a given mast rake. I can tell you first hand because my old Waterat had a unique transom that was flush with Station 11 and was higher than the Waterat standard. This resulted in a reading that was about 2″ greater using the standard method. The Rondar transom geometry is different from the Waterat as well. In theory, Ethan Bixby’s system should be far more accurate and repeatable.

It would be interesting just to cross reference this alternate mast rake measurement and see how consistent people’s calibration is using the conventional measurement system. I hope you guys have a great weekend of training. I wish I could be there.

Craig Thompson e:iqcraig@gmail.com


505 Hull tactics for the 2014 season.

Things are changing rapidly for the first time in many years in the hull and boat configurations now available in the 505 fleet. After 20 years of Rondar domination, with a few other waterat’s and fremantle hulls, 2013 see’s a major change in available hull designs.

The polish have entered the fleet, with what looks like a copy of the Rondar moulds. With few internal structural elements, between the hull center-line and the critical front bulkhead to centerboard casing, it will be interesting to see how stiff this boat will be particularly upwind in tough conditions. She does have an offset port-side spinnaker chute (originated by the USA teams back in the 1980’s), which is trying to lighten the ends to increase performance on the critical first windward leg.

Ovington are entering the market, supplying Holgar Jess and others, they have returned the Rondar moulds back to the manufacturer (Ouch! – lets see if Rondar’s can be bothered to re-engineer their moulds) after years of producing less than perfect boats. Let’s hope that Ovington can build boats that actually measure this time round?

Parker’s return with a revolutionary  and innovative International 505, engineered for maximum performance and acceleration, this boat has been optimized for the higher range performance, not ignoring the variable European and East Coast USA weather conditions, but primed for the very high winds and wave patterns of San Francisco bay.

Getting the most out of performance racing dinghy design is a combination of understanding how International 505 hulls perform. In the past most believe that extremely narrow and flat boats are best. However, these are slow in the turn and become sticky in tough acceleration and de-acceleration environments. Fuller boats, stand higher, though they have more surface area, they are more tolerant to variable speeds and as such accelerate much faster to the optimum speed.

So Parker’s have build an “acceleration” model, through extensive study of events like the San Francisco (2009) worlds and Hamilton Island (2011) top performers and 30 years working with the likes of Steve Benjamin, Peter Colclough and Krister Bergstrom, to produce a hull that is super-stiff. With (17) interconnecting mono-cock hull structures (a structure, such as an aircraft or boat, in which the skin absorbs all or most of the stresses to which the body is subjected) with rigid fore and aft structures connecting the forward bulkhead, through the mast gate to the front of the centerboard case, thus reducing flexing and energy dispersion (that slows the hull down). This maximizes the power generated through the hull, and when you power up, you want this power in straight-line speed not bending the hull out of alignment.

Parker’s have also maximized the boat width, being some 8 mm wider than the past Rondars and to the maximum hull length, ensuring maximum upwind performance.

The addition of the first A-frame mast-gate also stiffens the boat in critical areas and locks the boat in (essentially the boat hull cannot flex in any direction), but this also opens up the crowded mast-gate bulkhead/deck intersection, making the boat easier to rig, operate and set-up.

So the worlds in Kiel 2014 will be interesting, lots of older Rondar 505’s will be on the water with world class sailors and a few new Ovington’s (perhaps) and a similar handful of Polish and Parker’s, game-on!~

Being biased, I know which boat I will be in.

David Parker with Bruce Parker are the co-designers and builders of the Parker International 505.

An Interview with Parker Shinn – East Coast US 505 sailor

David Parker, had the opportunity to interview Parker Shinn who has been delivering some great results recently, so here’s some insights into sailing the International 505.

Parker 505

“What is it about the International 505 experience keeps you attracted to the class?”
Parker Shinn The 505 is in many ways the perfect combination. The boat is exciting, challenging to sail and offers excellent racing all around the world. At the same time, it’s hard to find better people in any class. There is a strong sense of friendship and camaraderie which is easy to see based on how much people are willing to help one another. It’s hard to to find anything better.

“If there is one innovation that the class must do to keep the class growing what do you think this should be?”

I think it’s important to strike a balance when it comes to innovation and thus far the 505 class has done an excellent job managing that process over the past several decades. I’m not sure there are any huge changes I would make to the boat, but one thing I think would be easy to do is lower the minimum weight since pretty much every boat out there carries corrector weights. With all the new materials now even the older boats are underweight and a lighter boat would liven it up a bit.

“Watching you sail, I get the impression that you read the wind shifts a lot.How are you calculating/co-ordinating the shifts with your crew and what changes do you make in the boat once you decide on a shift tactic?”

That’s a pretty complicated question, but I think it’s critical to have good communication with your crew. As a skipper in a 505 your hands are pretty full making adjustments and steering the boat well so I’ll consistently ask my crew questions about how certain things are unfolding on the race course. Usually we’re talking about compass headings, our angles compared to other boats, what mode we should be in based upon what we are trying to do tactically, and where pressure is on the course. If we’re consistently talking about these things it helps me to keep a mental picture of the race course. Then I can take shorter glances away from the boat to ultimately make a tactical decision.

“Which past or current 505 sailor inspires you and why?”

Howie Hamlin and Mike Martin have had the largest impact on my 505 sailing. They were the ones who helped me get into the class when I was young and gave me a lot of great examples to follow. The professionalism of their entire program was something that I hadn’t seen before and gave me an understanding of what it took to be the best, but it never detracted from their willingness to help other people in the class (myself included).

“I believe that the Barbados 505 worlds in April is your 4th 505 worlds event. What’s your personal goal?”

The last one I raced was in Adelaide and we had a respectable finish in the top 30, but I think there’s a lot plenty of room to improve. I learned after that worlds that I had been sailing with a centerboard beak that was too short for the past several years, which made it difficult to put the bow down in breeze so we always felt off the pace. The boat I’m racing now feels tuned really well so I’m excited to see how we do and I’m hoping for a personal best.

“Give a new-comer some advice on sailing the 505?”

Find the best people and ask them tons of questions. Sit next to them at dinner or find them after racing in the boat park and pick their brains on tuning, tactics, rigging systems, technique and anything else you can think of. The 505 is a complex boat but that’s part of the beauty of it. It takes a long time to learn how to tune it perfectly for every condition and you can dramatically speed up the process. There is a wealth of knowledge and most people are glad to share it.

Parker, thank you for sharing some insights.