Incredible "Secrets of Yacht Design" website located...

I have had some problems with attachments, but if everything went OK, you should be seeing a picture of a planing Mac26x. What you don't see is the rig. I guess the owner realized that the Mac is not a sailboat and decided to get rid of it...

 

somenone 's beginning to use this boat for what is suited to do: motoring!!!
next step: throw away those unuseful rudders, remove those ugly stanchions and lifelines and palace a modern stainless pulpit, get a good flying bridge and enjoy your motorboat!!!

Mistral

 

A infamous idiot - eh? We are literally in fog this morning.


The I-14 rudder pictured yesterday, complements of Richmond Point Yacht Club, as is the Murrelet II, is mostly used apparently in keeping the bow of the boat from a nose dive. You are correct. It is not the primary source of lift. The horizontal foils are trimmed by pushing down the cap lever on top of the rudder at the appropriate time. We are fortunate in the Olympia Washington area in that the Columbia river is but a few hours away. The Gorge on the Columbia is believed by some to be the most active sailing area in the world even overtaking the sailing areas in your country. I do not buy into that but I do suspect it is the most active in the US.

The above is the Tasar, which you will find also on the Columbia River. However, these are from the Worlds when they were held in the Straits of Juan DeFuca. (40 foot waves caused a semester-at-sea vessel to return to port there last week.) The Tasar is the dinghy I believe most resembles the Mac26x in planing mode. If you buy into the notion that Tasars plane then you should recognized that the Mac26x does as well. It is not the kind of jump to warp speed thing that the Melges and I-14 folks get. The planing mode is entered in a less dramatic way and your crew may not notice that you have gotten to this third mode of sailing. But you will see double digits on your GPS.

The pioneer owners of the Mac26x apparently experimented with horosontal foils on the outboards which are lifted and dropped by hydrolics.

The above vessel followed those pioneers, in spite of the manufacturer adding a special safety warning to the owners manuals. The engine manufacture did not consider the small horosontals an issue. Plus, many X owners had already adopted the long used by prior model owners of blowing out the ballast with raft inflators so that you were confident it was empty. This is what Macgregor Yachts says:

"Do not install a lifting hydrofoil on the cavitation plate of the outboard motor. These are airfoil shaped wings, offered in various sizes and shapes. Their purpose is to provide lift at the stern of the boat. This raises the stern and forces the bow down, allowing the boat to get up on a plane more quickly. If they do keep the boat level when coming up on a plane, the ballast tank may not drain completely when the boat is underway. You may think you have an empty tank, but you may not. These hydrofoils create another problem when the boat turns or leans sideways while underway. The lift that they provide goes straight up the centerline of the outboard motor, adding a strong force to promote further leaning or capsize. These devices can exert a large amount of force; enough to snap off the cavitation plate that is cast as part of the drive shaft housing. Avoid them."


The Mac26x boat plains at speed undersail without lifting hydrofoils on a deployed outboard. The early model rudder brackets were substantially reinforced by 1999 because these rudders are lifting foils and do that job. You can see the stainless steel brackets on the photo of the Wind. Well kind of. One day I will find a pre 1997 Mac26x with the first generation brackets. They were reinforced likely owing to the mechanics of planing under sail. The rudders are not deployed when motoring at speed. Under sail, these foils do gradually change the pitch of the boat into a more nose up possition when pushing hard. You are instructed to move the crew is as far back as possible to get the bow higher. A high bow reduces the length at waterline which decreases the displacement hull speed meaning that you are into forced mode at a lower speed than would be indicated by math. By moving the crew forward, the Mac26x crests her bow wake and is plaining. Sustained planing mode is not at all difficult.

In light winds, the outboard hydralics would have the lower unit out of the water entirely so any lifting hydrofoil would not will cause drag and thus make boat slower.... I do see your point. On the I-14 you state The rudder case can be pivoted back ie bottom of the rudder moves more aft to change the angle off attack. When you turn up wind you pull the line controling rudder pitch and bring the rudder forward again. Outboard engin lower unit lifting hydrofoils do not have that level of tuning. But I think there is possibility for assisted planing without turning the engine on. When the X is in forced mode, instead of moving crew forward you might be able to adjust the bow attitude and crest the bow wave to reach plane. Perhaps you are correct and the horozontal fins need to be larger. This is just fun chat. I do not intend to do a modification like this. It appears that MacGregor Yacts is concerned more about the transition from ballasted to unballasted state than other issues. What do you think?

 

i may seem boring, but i'm still waiting for a MAC26 planing picture, i mean with engine off....
This thread is becoming really boring :-(((


Mistral

 

Frankie, do you really believe what you've just written????????

Mistral

 

OK, Mistral. I have not had much luck with my photos. So here is a photo of the wake that I believed proof of planing under sail.

So let it rip. I have been here before - thats 3 knots you idiot - etc etc. Only it was 9.5 to 12 MPH sustained for over 20 minutes off Shilshole. We were passing two masted schooners of 50 foot with all cloth flying. The wake is powerboat like - or catamaran like. Heel over 11 degrees. True wind from behind. I have also tried

and this photo which I thought very convicing

but, these photos, which I believed proof, mean nothing to those who define planing. So I stopped arguing it. It is true that the mac26x does double digits, even 17 MPH and that the manufacturer claims the X to be its planing sailboat model and the M to be a surfing model. The keel boat trained have little chance of reaching those speeds but the dinghy trained and those new to the sport can get there easy by putting an intermediate point reef into the main, and sailing on a high normal wind day - say 12 to 17mph with full water ballast. Fire away. We are all vulnerable in our rears. Mine is now exposed. Note the bracket on the last photo that holds the lifting rudder foil.

 

Frank, I don't think you have ever been aboard a planing sailboat- Those pictures are from a 2-4 knot displacement cruise, nothing more.

 

Ha ha ha! I knew we'd get here eventually. Frankie actually believes those pictures are of a planing wake. He has absolutely no idea what planing is, even after seeing the great pictures pkoken posted yesterday.

"Subtle transition" [Sorry, actual quote is "The planing mode is entered in a less dramatic way and your crew may not notice ..."]... as in "never happened" you dolt.

 

The early model rudder brackets were substantially reinforced by 1999 because these rudders are lifting foils and do that job. You can see the stainless steel brackets on the photo of the Wind. Well kind of. One day I will find a pre 1997 Mac26x with the first generation brackets. They were reinforced likely owing to the mechanics of planing under sail. The rudders are not deployed when motoring at speed. Under sail, these foils do gradually change the pitch of the boat into a more nose up possition when pushing hard. You are instructed to move the crew is as far back as possible to get the bow higher. A high bow reduces the length at waterline which decreases the displacement hull speed meaning that you are into forced mode at a lower speed than would be indicated by math. By moving the crew forward, the Mac26x crests her bow wake and is plaining. Sustained planing mode is not at all difficult.

Frankie, do you really believe what you've just written????????

I am struggling with it. Of all the discussion on all the forums I have been involved with involving my ride - the planing capabilities of the vessel have been the most controversial.

Certainly the boat planes under motor power. The manufacturer wants you to protect the rudders while motoring by lifting them when the boat is motoring above 7 MPH. That is right at the thoretical max hull speed for a displacement hull of 22 feet (7.22 MPH). I estimate that when crew are sitting aft that 22 feet is about what is presented to the water. However, possibly all of us have motored with the rudders down (operator error) at high speed and haven't ripped off the rudder fins.

When I first drafted the statement Under sail, these foils do gradually change the pitch of the boat into a more nose up possition when pushing hard. I was thinking of one fin and two fin operation. On a 11 to 15 degree heel, I think I feel the boat lift under me when I drop the second rudder, which brings the nose down. You are instructed to lift a rudder when going down wind which would lift the bow then (right?). The flat portion of the hull in the rear also is contributing to lift when you get speed. Perhapse the lift isn't as great as the boat you are thinking of and most of the lift comes from hull characteristics. But the rudders are definately lifting foils.

One of the definitions of planing that I picked up was that if the wind indicator points forward of midship on a downwind run then you are planing. So I took this photo when my notions were being ridiculed a few years back.

What I believe is that Roger MacGregor put his career reputation on the line with the Mac26x model. He claims the boat is revolutionary and does 17 MPH under sail. I have no reputation to loose on this. So I can at least speak and try to understand and match that performance. The moment I admitted to being a former power boater, I lost credibility with a good number of "sailors". The same thing happens with those who admit to being multi-hullers so I just do not take it seriously anymore. What do you think? Fog is lifting? OK, rip away. I will be unavalable for several days and unable to respond. So have fun.

 

Thanks, Frankie - I needed a good laugh. However, you now owe me a keyboard, as this one is drowned

Steve

 

Frank, That top picture sure looks like the South Sound (Dana Passage area) not Shilshoal area. Now the attached picture (by Sean Trew) was taken of my boat (S2 7.9) going downwind in 10-15kts of wind. We were sailing at 7kts overground against a .5 kt current in Dana Passage and were NOT planing. How do you feel this compares to your photo?

 

Planing in the Mac26x is like the slot effect, generations of sailors have all experienced it and know its there whether or not you can actually see it. The fact that Murrelet nevers planes in the presence of another boat that can attest to it merely means no one understands what conditions are right for it.

Afterall by the definition provided the Mac26x only qualifies as a non-planing boat unlike ULDBs. So we know the normal planing winds only exist around the Mac26x and others never see it because it doesn't exist in the rest of the world.

 

The Mac26x is actually very shy. It doesn't like to show off, and so will only plane when no one except Frank is looking.

 

sorry Frank
rudders are not lifting foil, that's all, anyway you can put it they're not lifting foil
T-foils like used in Moth may work as a lifting foil, properly designed and calculated, nor the rudder nor the horizontal fins of your engine

planing means that your CG raises up 'cause of dynamic lift, that's all
nothing to do with apparent wind angle as you're claiming, i don't know who suggested you such a rubbish notion, but you'd better look for better sources for your sailing culture

Mistral

 

Good Morning Boat Designers and Sailing Anarchists:

Let me first request a change in protocal. Rather than hailing Murrelet as "Kiss Me Arse" in Boundary Bay by radio on channel 16, try KMA or Murrelet. Still, nice gag. Hope the Coast Guard didn't mind so much. 10,000 views of this thread on Murrelet's 6 year aniversery. Happy Valentines Day!

Old Business

usa2

Canting keels dont typically fall off if they aren't in storms or get damaged by a grounding. The problem with them is that they are only really efficient offshore, where you are more likely to run into a storm than not.

With modern reporting, only thrill seakers will run into storms. The storms and hurricanes we had this season on the east coast of the USA confirmed the notion that a distance no greater than 60 miles is all that is needed to avoid storms. This means only operators of slow sailing and motoring vessels can claim competency while relating a story about weathering a storm at sea. That would not be the operator of a race boat.

Well there could be an exception, but seriously, with modern reporting you have to question operator competency in this situation. Were the crew and captain drunk with race enthusiasm?

You cant build an inshore round the buoys racer with a canting keel, because on upwind legs it wont be able to compete in tacking duels without getting killed.

Wow. Such a great statement! I was reviewing a lubber's dictionary on Sunday. This is a dictionary that defines the word Ahoy as "the first of many four letter words that will be exchanged after two sailors meet.". Every definition - even that one - had some ring of truth. A centerboard was defined as a movable keel always stuck in the down position. From the minds of lubbers came insite. Canting keels are - of course - also movable keels. So are dagger boards. In the USA, most race fleets prohibit centerboarders, and daggerboards, which are a kind of centerboard, but not yet canters from altering the configuration of the board during a race. If it is allowed the penulty in rating is overwhelming and usually the boat must race with the board fully extended.

You are generally correct that on upwind legs many fixed keelers will outperform centerboarders. But on downwind legs, when the board can be retracted, this disadvantage is compensated for because the centerboarder, when sailed as designed, will have less drag owing to the wetted surface of the board being removed by retraction. You are incorrect on the canters. The canters have forward foils or other mechanisms that allow them to sail DIRECTLY UP TRUE WIND - at least that is the claim for the Schock 40. The canters likely will win tacking duals.

New Business

USA2,

The keels on the big boats, where the concept makes the biggest difference, should be strong enough to stand up to a huge storm- especially if the boat was designed with line honours in the Sydney-Hobart in mind.

Prior to about 1900, all sailing vessels used internal (also called bilge) ballast in the form of cargo, stone and, as in the case of Spray, concrete. Spray continues to be disparaged as a cheep boat because of her ballast.Yet this method of ballasting has been proven by time. Oriole is a 1918 George Owen (of MIT) racing yacht that was intended to be the largest yacht on the Great Lakes. She is larger than the current day maxis at 102 foot over all and 91 foot at the water line. The way to honor the sailors of the past is to preserve their vessels and in 2003 Oriole underwent a major overhaul.

The most significant make over was the removal of CONCRETE ballast which was replaced with lead. Over the years Oriole gained a following among the less "yachty" and became known as the peoples boat. However it must have been distressing to the well heeled to have an internal concrete ballasted vessel better them.

Oriole came in second in the 1998 Victoria-Maui race and in 2000 finished more than 19 hours ahead on corrected time over some of the most modern raceboats on the Pacific. In 1998 she finished seventh in the Sydney-Hobart. This was the infamous race where 55 people had to be rescued, 5 boats sank, and 66 boats retired out of the 115 that started, 6 sailor's lives were lost during that race. To say the Oriole's design is proven, understates the contributions she has made to the science of sailing. The 102 ft ketch is currently owned by the Canadian Navy and is used for training of Regular and Reserve Canadian Navy members. It is distressing to those who would like to think of Oriole as the people's boat to have the concrete removed and replaced with an expensive substitute that has not been shown any more effective. But that lead is still internal.

The notions of long weighted fins just have not been shown correct by the test of time is the point. Designers need to get beyond that. Shorter weighted fins and long retractable possibly unweighted fins are the future of sailing yacht design. Oriole and Spray show us that this is a return to the sensibilities of the 1900s.