Jon: super cool! What was the actual speed of the boat in the picture-any idea? What would you say the actual top speed of the model was?
How close to the wind do you think this concept could sail - not for aspeedrecord but just sailing?
Thanks for the pictures and info!
Doug Lord
–High Technology Sailing/Racing
I just have a moment to check in and I wanted to make a couple of observations:
I once again want to state that there needs to be sail size limits. If the model of the monofoil MK5 is stable enough to free sail (without radio control) then the full size boat probably will be stable as well. So, all John would have to do is put a radio reciever in the cockpit of the full size boat and it could be considered a radio controlled boat, right? The radio would not actually have to do anything… Then he just lets the full size boat go and it sails away at 70 knots and he would have then set the speed record for radio controlled boats. This is why I think we need a sail size limitiation…
I think you should consider shortening the course to 20 or 30 meters rather than 100m. Assuming your boat is moving pretty quickly, you will have a hard time keeping up with your model in order to contol it. A 20 or 30 meter course would allow you to stand in one spot and control your boat through the course. But 100m would require you to drive a car along beside your boat which would serously limit the places where such records attempts could be made and certainly make it much more difficult for the average guy to go out and set a record.
When I was working on the human powered hydrofoil “Decavitator” in college, we rigged up a light beam timing system. Two parallel light beams were shone across the river seperated by 100 meters. The clock would start when the boat tripped the first light beam and stop when it tripped the second light beam. An even simpler setup is to setup two gates (using buoys) and simply use a stopwatch to record the time it takes the boat to sail from the first gate through to the second gate. BTW both of these course have a direction associated with them, but if a boat wanted to sail dead down wind then you would just need to set up the course so that it was aligned with the wind.
Carry on!
Will Gorgen
[:-batman] <font color=“orange”><font size=“2”>Jon</font id=“size2”></font id=“orange”>, Great posts, thanks for the pictures. [:-bigeyes]
This thread is getting a bit unwieldy now with something like 63 replies making for some dedicated reading required to get up to speed,
(pun intended) [:-drool]
<font color=“orange”><font size=“2”>Jon</font id=“size2”></font id=“orange”> would you consider recording a timed run over a 100 metre course to set as a benchmark for others here to aim for? [:-goldfish]
No WSSRC commissioners, just an unofficial yardstick giving you the bragging rights on this forum and the respect of us all. [:-jester]
<font color=“purple”><font size=“2”>Will</font id=“size2”></font id=“purple”>, buried back in previous posts is my letter to the <font color=“red”><font size=“2”>Speed Council</font id=“size2”></font id=“red”> where I ask for two categories, up to 1sq metre & up to 2sq metres of sail area.[:-sing]
This would hopefully cover your scenario of man carrying craft fitted with remote control.[:-witch]
The 100m course was thought of as being one fifth of the full size course for roughly one fifth size craft. If you stood half way you would only have to view your craft from a maximum of say eighty metres allowing for a 30 m run up?[:-magnify]
If anyone wants to post a time for a 20m course then go for it. <font color=“maroon”><font size=“2”>JUST DO IT!</font id=“size2”></font id=“maroon”>[:-timebm][:-taped][:-turtle][:-tophat]
Do it NOW before it`s too late.
Will,
Entirely sensible comments and exactly my point. Wing/sail/blade area classes are the only way that I can see of making this event make any sense.
For info, the way I measured the Monofoil model performance was by analysis of filmed runs. My digital camera records at 15 frames per second so, knowing a key dimension on the model allows a plot of filmed reference length (which varies with distance from the camera) and number of reference lengths covered per frame… Out drops a speed-time history. The film clip on our website and the still I posted yesterday shows the boat doing about 16kts in a wind at model height of about 8kts. It can go faster but the conditions are very critical for a model. A full scale wind speed range would be about 10 to 25 knots, the corresponding model range is nearer to 7 to 11 knots which is a pretty narrow window and makes the probability of success on a given day very low. The model here has a wing span of 32 inches and so is quite small. I would consider a 1 metre class to be the smallest practical size to gain any reasonable chance of a successful event.
Another approach may be to borrow an idea from the freeflight model aircraft world and run a postal competition (nowadays I suppose this would be an Email competition). These rely on individuals providing acceptable evidence of their exploits. Digital AVI films would be a good approach as the data could be analysed independently although full resolution films take a lot of memory which may become a problem. A top ten league could then be established for a sail-off event (championship?).
One other bit of information may be of help. Monofoil MK 5 has a wing area of 0.162 square metres. To meet a proposed 1 square metre class I would need to scale up by a linear factor of approximately 2.5, this would be quite a big model, ie, approximately a 2 metre span wing. I would regard this as a bit of a handful. Perhaps a .5 square metre class is a good practical starting point rather than the 1 metre class that I so misguidedly recommended in my first paragraph?[:-banghead]
In response to a couple of questions raised earlier, the MK 5 model will sail to within about 20 degrees of the true wind although there is little point as the best VMG to windward occurs at an angle of about 50 degrees. Best speed is on a course of about 115 degrees and the fastest speed that this model has been clocked at was 22 knots (but not for long…). The single foil is made from stainless steel and has been replaced twice due to erosion on the sand when the model runs aground at speed. I will not be doing any more model work on this concept in the near future as all efforts are now towards the full sized boat.
Just a few thoughts as I know how frustrating model testing can be!
Ian,
Your comments about the amount of reading for this topic are a good reflection of the serious thought being put into it.
Having read thru most of them and asking some “devil’s advocate” type questions,the idea of only one or two rules has steadily evolved to the point where now it is possible to establish by comments made by everyone that the rules for this attempt are :-
<u>COURSE.</u>
a).The course shall be set at 100 metres overall.
b).The timing section of the course shall begin at a point 25 metres from the entry point and finish 50 metres further on.
c).The setting of the course in relation to natural wind speed and direction shall be solely at the discretion of the competitor.
d).No alteration to the course shall be allowed once the vessel enters the water.
e).The competitor shall be allowed 30 minutes from when the vessel enters the water in which to make an attempt on establishing a record.
<u>SPEED</u>
a).The speed established for the record attempt shall be calculated on the basis of the elapsed time taken for the vessel to pass between 2 fixed points on the course set 50 metres apart.
b).The speed established is the AVERAGE speed over the measured course,not the highest speed reached.
c).The formula for calculating the speed record is :- (50/Time) x 3.6 = Speed Km/Hr.
There should also be a section detailing the means of measuring the elapsed time and the attendance of officials.As far as that is concerned,would it be easier for someone from Guiness BoR to control it rather than WSSC.
Hope this is of help and sets what I referred to in an earlier post as a "fair dinkum " set of rules.
Ross
Experience is what identifies a mistake the next time I make it.
In my opinion, to keep this thing so that the more or less average modeller could build something I would think there should be three classes: .5, 1 and 2 sq, meters. (Two square meters is 20 square feet!)
And I definietly think limiting channels on the “ultimate” in highspeed rc sailing is counterproductive.
Some ideas could easily use 5 channels…
Doug Lord
–High Technology Sailing/Racing
<font color=“green”><font size=“2”>Ross,</font id=“size2”></font id=“green”> Thank you so much for your input. You have obviously been giving this much thought and I can agree with most of your <font color=“blue”><font size=“2”>“RULES”</font id=“size2”></font id=“blue”>[:-propeller]
We need to be aware of a couple of things.
Thing 1; The <font color=“red”><font size=“2”>WSSRC</font id=“size2”></font id=“red”> are the sole guardians of the<font color=“red”><font size=“2”> Official World Speed Records.</font id=“size2”></font id=“red”>They have established rules and conditions for the attempts and ratification of all types of World Speed Records. They have yet to approve the establishment of a category for remote control craft so we are at this stage totally on our own with whatever we do.[:-pirate]
Thing 2; We can make any rules we wish, to establish and manage,
<font color=“blue”><font size=“3”>“RC SAILING.NET FORUM, SAILING SPEED RECORDS”.</font id=“size3”></font id=“blue”>[:-party][:-slaphappy][:-turtle][:-tophat][:-witch][;-xmas][;)]
I personally am happy with most of your suggestions with the following exceptions.
Radio should not be the only method of control allowed and the number of functions should be unlimited. I have been very careful to use the term <font size=“2”>REMOTE</font id=“size2”> rather than radio control.
Why restrict the method let alone the number of
functions allowed. (Think,infrared,GPS,audio homing,radar etc.
The course could be set at 20 50 or 100 metres and the timing as you suggest, but IMHO it is not necessary to specify the run up distance or put any time restrictions on any attempt.[:-weepn][:-turtle]
This is not an event like a regatta. we do not have to make it any harder than it already is, simply establish guidelines to allow those who are interested to consider the challenge as achievable[:-snorkel][:-splat][:-skull][:-party]
PS Ross I much prefer your new sign off, More fitting for a man of intelligence and humor.
Do it NOW before it`s too late.
Ross,
I think you have a good basic set of rules there with a couple of comments:
I agree with Doug and Ian regarding the number of control channels, this seems an unecessary restriction for an “ultimate” class.
Your suggested rule “No secondary means of propulsion,ie any apparatus that indirectly uses or converts the laws of aerodynamics into another means of propulsion is not permitted.” bothers me a little. Full scale speedsailing is restricted to anything that gains its propulsion solely from the wind with the caveat that energy storage devices are forbidden. I would stick to that rule otherwise perfectly valid solutions such as wind turbine boats would be excluded and the event would be the poorer for it.
One other point is that in full scale speedsailing, such as at Weymouth, the course is regularly adjusted to take best advantage of the wind at the time and to accomodate the “boat most likely’s” best course. Remember that this is about ultimate speed by wind power, not the imposition of arbitrary restrictions. I do not therefore think that the rule regarding no course adjustments once the boat is on the water is a useful rule.
I like your comment that speeds should be average over the course, we have had suggestions from some kiteboarders that a short course would be better for them. This is because a kiteboard can dive the kite through the power zone and generate a very high, but unsustainable transient speed. So far this has been resisted as it would not be a genuine sustainable performance.
This appeals to me!
Jon.
What do you guys think of three sail area classes: .5sqm(750sq.in.) , 1sq.m(1550sq.in.) , and 2 sq.m(3100sq.in) ? Isn’t there a three class spread in full size speed sailing?
Seems like it could allow more participation as well as covering the “real” world of rc sailing somewhat better than just one SA category would…
Doug Lord
–High Technology Sailing/Racing
Ian,
Do you realise what you have done [:-weepn] I never thought I’d see the day when a Kiwi [:-cyclops] would would acknowledge that there was at least one <font color=“red”>Aussie</font id=“red”> with <font color=“blue”>INTELLIGENCE</font id=“blue”> [:-graduate] and <font color=“green”>HUMOUR</font id=“green”>.
[:-jester] If I were you I’d go into hiding [:-paperbag] [-crzwom] for a couple of weeks until that news died down.
Your idea of making your own set of “R/C Sailing Speed Records” is fine, but if you want to have the record ratified by the WSSRC then you would need to have a set of rules comparable to those for “big boats” if they are to be accepted.
All I have done in drafting these suggested rules is gone back and read through all the posts on the subject and extracted “actual rules” as they have been suggested or stipulated by other contributors.
eg. My anemometer driven propellor was ruled out by you “propellor driven craft are not eligible for a sailing record” Hence the rule re secondary means of propulsion.
See also WSSRC Rule 21c --“natural forces must always remain the sole means of propulsion”.
In answer to comments by Doug and John :-
<u>Sail Size</u>.
This rule only sets the maximum size,you are quite able to use smaller sails if you want to.
<u>Channels</u>.
All (?) classes of r/c yachts are limited to 2 channels aren’t they ? What would you want 5 channels for ?, canting keels, movable ballast etc.
I’ve gone to the WSSRC web site and gleaned from what little is there some amendments to what I proposed.
COURSE. Their rules indicate that the vessel must accelerate from rest, so the rules regarding length of course,position of timing gates would need to be changed.HOWEVER I feel that r/c models should be allowed a flying start purely from a practical point of view, it is a lot different controlling a boat from onboard than from onshore 100 metres away.
Finally, the comments re Guiness BoR came out of another WSSRC ruling which states that all the time,travel and administrative costs of their officials have to be paid for in advance.They have to booked in advance as well for any record attempt to be ratified, it can’t be done after the event. Are there any officials in NZ/Aust ?
I have requested a copy of the WSSRC rules and will go through them and see [:-magnify] if they can be modified to apply to r/c sailing in a form acceptable to them.
Ross.[:-disguise][:-graduate][}:)][:-bulb][:-bonc01][:-idea][:D]
Experience is what identifies a mistake the next time I make it.
Check out:
http://www.sailspeedrecords.com/500.html
The WSSRC/ISAF recognise NINE classes for the 500 meter world record attempts.
I would think rc sailing should have at least three classes(.5m, 1m,2m SA) qualifying for a record on a shorter course.I would hope we could include that in any proposal to them…
Doug Lord
–High Technology Sailing/Racing
Ross,
Your anemometer driven propellor boat would be perfectly legal under current full sized rules as the only energy input comes from the wind. Such boats have been proposed but have not appeared as serious contenders since the perpetrators do not yet seem to have realised that the ratio between blade area and water screw area need to be similar to the ratio between sail area and keel/foil area for a conventional boat. On the wind turbine side most that I have seen are hopelessly under bladed in any case, it is however a legal solution.
The full scale rules only require the vessel to start from rest under wind power to avoid designs that get dropped into the water at high speed. Bob Downhill, one of the leading lights of the Weymouth organising panel, has often said that the first ten knots are the most important since many potentially fast craft are incapable of getting over the “hump”. This rule exists only to ensure that the freak boat that wins is not too freaky and the actual course itself is always entered with a flying start.
As regards the number of channels. Some full scale boats have required multiple crews for more than just ballast. I don’t like this since it looks like bad engineering but this is just my personal prejudice, however, if a designer produces a model that sails past everything but needs three channels you appear to be saying that this is not a sailing speed record. I personally don’t feel too strongly about this as I can sail a Monofoil model with no channels, others may have stronger feelings!
Jon.
Yesterday we decided to get out and see how fast our AC15 goes. It was blowing about 20 knots, we fitted the C Rig and sailed it out into the Marina. There is a breakwater that floats only 300mm above the water, providing us with flat water and unobstructed wind. We situated the driver in the middle of the course and sailed the boat out beyond the start line. When the starter situated at the line dropped his arm the clock was started. The run is 73m long and took a time of 22 seconds. This equates to a speed of 6.46 knots.
Today we decide to step thing up a bit and did some mods to the boat.
A couple of extra eyelets in the sails allowed us to lift the booms so they don’t drag in the water when heeled.
The next mod has completely transformed the boat. We have added an IOM keel, taped across the deck with the bulb positioned about 200mm outside the gunwale. This has significantly increased the power and the twitchyness of the boat.
Unfotunately the wind was gusting to 36 knots and timed runs nearly turned to disaster.
Anyway we are posting a speed on this site, and aim to better it in the coming days. Not sure of the sail area of an AC15 C rig. Might try and measue that tomorrow and post some photos of our setup.
6.46 knots
Brett
Is there any simple way of uploading an avi clip to this forum? I have several of Monofoil running at high speed and if this is possible and would also be of interest I will be happy to do this.
Jon Howes
Nope - not possible <s>John</s> Jon. Best you can do is save the clip to a website that allows that format, and place a link to it from here.
edit - sorry about name spelling !
<font color=“red”><font size=“2”>JON</font id=“size2”></font id=“red”>, Do you have a run that you timed that you could post here as a yardstick for us all to aspire to? [:-clock]
You are the only serious manned speed craft designer that we have on this forum as far as I am aware.[8D]
Your model is also a serious attempt to test your design ideas and is a credit to you.
<font color=“brown”><font size=“2”>Tell us please, please</font id=“size2”></font id=“brown”>.[:-jump2]
Do it NOW before it`s too late.
Ian,
OK, here is the analysis of the run shown on our website.
You need to understand that the purpose of all the Monofoil models was to validate the analysis, not to set a model record and hence I have no data for very long runs. They have occurred but the model gets so far from the camera that the analysis is useless. The run shown in the files had a useful length of about 18 metres with an average speed of 11.51 knots, not very fast but useful if the speed-time history is reviewed revealing a peak of about 15 knots. The waterline length of the bit in the water at peak speed is 0.6 inches (the foil chord). As the foil is a ventilated design this is governed by Froude number just like a surface wave system. Full scale chord of the same bit is 9 inches giving a scaled speed for this run of 58 knots. Other runs have produced higher peak speeds but sometimes with less satisfying levels of smoothness hence the inclusion of this run on our website.
I am not planning to go out and chase a conventional timed run for the following reasons:
1.The wind range for this small model is very narrow, about 7 to 11 knots at rig height. Getting these conditions at the test site (West Wittering on the UK’s south coast) occurs only with a fairly low probability.
2.Setting up a run over a measured course with a free-sailing model and observers with lightning reactions is nearly impossible given that the people involved need to be on call for the right conditions.
I strongly recommend the use and analysis of digital film as a way of measuring speed as it needs a minimum number of people and allows careful analysis at leisure.
The two files uploaded here are a composition of the run at 1/3 second intervals and a speed/time plot of the run deduced from the composition.
The reasons for using a free-sailing model rather than one with wireless installed are that models like this are quicker to build, more expendable (you should see some of the crashes of earlier models!) and when released are in an exactly known configuration.
Enjoy,
Jon
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As posted elsewhere, this is a speed run that sets a standard for AC15`s.