To read Malcolm's Blog click here.
Fri, 4 Jul 08 11:13
We have learnt a great deal from sailing Vestas SailRocket in the first half of 2008, and can look forward to moving into the ‘record zone’ in the autumn. See also designer's video blog.
Speed on Target
We are pleased to see that the speeds for nearly every run are in line with predictions and hence confirm the likelihood of getting to 50knots.The last run (53) is well above prediction and represents our highest boat/wind ratio ever!
Plenty to come
Here is a list of the estimated extra speed increases relative to run 32 (44knots peak)
- Strut fairing 1.0k
- String reduction 0.5k
- Rudder retraction 4.0k
- Flap deployment 2.0k
- Met mast 0.2k
- Wing end caps 0.2k
- TOTAL 7.9k
- PLUS 3K PER 1K WIND INCREASE
Steering
We have learnt that the steering behaviour can be quite complex and the process of tuning or ‘balancing’ the boat is more difficult than expected. The result is that Paul's task as pilot has been too demanding and he has not yet felt the required repeatability of response needed to operate the boat in the higher wind speeds especially close to the beach. It is not a forgiving situation sailing 10m from a beach at 45knots and beyond!
Valuable experience has however been acquired with retracting the low speed rudder and operating the hand steered skeg trim tab. We now suspect there are some strong interactions between the two rudders and try to retract the low speed rudder as early as possible.
Naively I thought measurement of the steering trim tab angle would give us a good measure of the steering load and thus enable the correct adjustments of wing position and skeg set angle. In reality its not nearly good enough because:
- The measurement itself is affected by twist/play
- The deployment angles are very small
- You need to estimate the local flow angle which is affected by the main foil upstream. There are significant uncertainties in this.
This was brought home by the large discrepancy (about 100kg for run 48) between our rudder load implied by measurements and those forecast by our mathematical model (we call it the ‘sim’). The sim says there should be about 10kg of load to leeward.
The answer lies in simply measuring the skeg force. We are currently sourcing two types of sensor that can do this and we expect these to be ready for resuming trials in August.
Crash
Unlike all previous crashes the last one was a direct result of a structural failure leading to loss of the skeg.
Without this control surface Vestas SailRocket behaved exactly as she did on previous crashes when there was no fixed skeg. That is – rounding into wind very quickly and backwinding the wing at speed, which caused failure of the crossbeam under compression loads transferred by the strut.
We have strengthened these details and made the skeg structurally independent of the rudder. In addition we have load tested the skeg to 185kg which is well above the load it will bear at top speed.
Wing
While the efficiency and power of the 16m2 wing is not in doubt there are some aspects to handling that are more difficult than we would wish.
The inability to dump most of power on sheet release alone is the key one.
We have a depower trip system which activates the centre flap to a large negative angle. The trouble is its one more thing for Paul to remember and do, and it interacts with the sheeting lines.
Instead we are making modifications to the wing flap fixed settings to achieve the best feathering we can and this will eliminate the backwinding tendency at slight cost in efficiency.
We are seriously considering a MK II wing as it will be possible to get very much better handling with a fresh start. This could be ready in October if we decide to go for it.
These changes to the wing can ease the start up and stopping sequences and give us more time at speed on each run which can be a real advantage especially if we are using the TRIMBLE gps for ratified record attempts when it is allowed to take any 500m course from the full track. As importantly, they also reduce the risk of accidents, particularly if we have to go out in stronger winds above 22knots.
Ground effect
A small but excellent development is the end plate on the cross beam ground effect flap. This not only works by inhibiting the pressure loss near the tip but has stiffened the flap which was bending out of the way of the wind and thus increases lift and efficiency in two ways. It can just be seen in the photo below.
Tue, 1 Jul 08 16:24
The weather window we were hoping for has fizzled out so we have decided to head back to the UK early.
We knew that there was going to be less liklihood of good sailing days at this time of year but decided to stay on just in case. We were looking forward to the upcoming weekend but things look set to continue weather-wise. Our resources could be better applied if we return in early mid August.
VESTAS SAILROCKET is already packed away inside her container and the operational area has been disassembled.
We will use the time wisely in the UK to review what has happened and what is to come. Whilst we haven't hit the speeds we were hoping for.... we haven't hit any brick walls either. The boat and team in general has come a long way in the past four months. Speeds well over 40 knots are now a common occurrence and I personally feel that we are ready to make another significant performance jump.
I know I keep saying it, but speed WILL come with control... and I feel we are getting close to having the necessary control to steer with precision at high speeds. Part of the joblist over the coming weeks will be to install sensors on the foils to give a better indication of what the balance of the boat is like.
The accident that occurred on Run 50 was simply that... an unpredicted accident. We have since load tested the whole skeg assembly to over 185 kg of side load half way down its span and there was no sign of it breaking.
Whilst our goal is simply to be the fastest whatever that speed need be, we are very aware that there is a race on to be the first to 50. We will be back in action as soon as the conditions are back. So the ball is pretty much in Hydroptere's court now. We sincerely wish them well as their passion, dedication and openess is a great model for achieving success way beyond mere speed sailing circles. We hope they go fast... but not that fast just yet!!!
The coming weeks will also allow us time to put together some videos which will be posted when done (remember my laptop got stolen and it has been quite a hindrance in the video editing department).
So hopefully it will only be a relatively temporary departure from speed-spot and once again, as usual, we will come back much stronger for it.
Cheers, Paul.
Mon, 30 Jun 08 10:41
Hi all,
Helena and I have just returned from three days trekking out in Damara Land about 200 km's North of Walvis Bay... and it was spectacular. Ah the solitude, the silence of the sunsets over spectacular vistas and the appreciation of simple pleasures like a fresh cup of tea... It was the perfect break.
Anyway, we are back... and sure enough, some things have changed in the world of speed sailing since we have been away. The WSSRC (governing body) have added a rule which basically says that the 500m outright record course must be in water over 50 cm deep (my knee joint begins at 50cm high). This effectively eliminates the possibility of wind and kite surfers from getting any benefits from ground effect in one form or another. Now like all rules it can be debated and pushed. Carrying a 50 or even 40 cm fin on a sailboard for speed sailing purposes is not viable... but it might be on another type of craft i.e. ours.
The fact is that there is a performance advantage for some craft when sailing in shallow water as they gain efficiency. We questioned the WSSRC about this some time ago and were advised that they were on the case. We are of the opinion that the outright speed sailing record for waterborne craft should be kept pure. By 'pure' I mean it should simply be the interaction of wind and water on a craft. The proximity of ground (or any other body)and its effect on the dynamics of the craft is known and it is real. To allow certain craft to push this corner of the rule would be to pollute the 'purity' of what this particular record is trying to achieve. Water could simply become a lubricant between the wind and the 'ground' (ground in one form or another). Now I see a lot of moaning on some forums from certain elements of the speed sailing fraternity who currently benefit from shallow water and a lot of their arguements I can sympathise with... but the fact is that the rule needed to get a little more specific. These same parties would be moaning their backsides off if some team of university students wanted to make a point and push the definition of shallow water much harder than they already have by building specific craft and courses to gain maximum advantage from this effect.
It does make it difficult for wind/kite surfers to determine what a viable course is i.e. "How close did you come in to the shore on that last run"? I have watched both disciplines very closely here on the Walvis Bay speed-course and noted the depth that they sail in. Typically, the windsurfers would be OK but the kitesurfers would fall foul (Many of the windsurfers would also on some runs). The fact still remains that they will still be able to sail in much shallower and hence flatter water than we could ever wish for. We draw slightly over 60 cm when planing... and generally are considering ourselves on the edge when we are in less than a meter. As far as finding the best water goes... they still have quite an edge.
I don't know if '50 cm' is the right amount and I'm sure that there will be plenty of debate on the subject. Whatever they all settle on, I personally think that it is a step in the right direction to maintain the aforementioned 'purity' of what a waterborne sailing craft is intended to be.
Now... what about the 'balloon-dragging-a-string-in-a-storm' clause?
The weather forecast still looks pretty average and we have to debate whether we should return to the UK earlier or later than planned. The useable tides are starting to creep into the afternoon again... but the wind is still absent.
Decisions, decisions.
Cheers, Paul
Thu, 26 Jun 08 08:56
Well, yesterday was our last chance to sail on these tides until the next set return early next week. There hasn't been much wind anyway. the fact is that we have probably overstayed our cureent weather window welcome.
We are considering returning to the UK in the near future as our time will be better spent if we return in the windier periods. I would expect to be back in mid-August.
We will save that decision for now. VESTAS SAILROCKET is fully prepped for her next outing. We nearly got out yesterday but the wind fizzled. The absence of both wind and water over the next few days, mixed with the fact that the boat is in good shape... will allow us the rare luxury to make a foray out into the big, beautiful and ever beckoning desert. We want to see some wildlife and get our heads out of the container and away from the boat for a change.
We will make the call on whether we return to the UK based upon the weather forecast we get when we come back in a few days.
Cheers, Paul.
Tue, 24 Jun 08 11:43
We are sitting here in a steady state of 'stand-by'. Every day we carry on with the tweaking whilst we wait. We didn't expect to still be here as this is not the season for good winds. We lost a month at the start of this session due to an unusual lack of wind and we have been trying at every opportunity to make the next break-through to take us further up the speed ladder.
I honestly feel that we are on the brink of a significant gain and thus find it difficult to walk away... even temporarily. we have a couple of days left on this set of afternoon tides... and then we have to wait through the afternoon low tides for the next session. If there is no wind for that week of opportunity then we will be forced to head back to the UK and spend our resources on a windier time of the year.
Fingers crossed for wind
Cheers, Paul.
Sat, 21 Jun 08 12:59
Righto, here is the follow up to yesterdays Run 53... with a real photo album covering the last few weeks.
Malcolm has looked over the Run 53 data and thinks it is pretty fine indicating our best wind-to-boat speed ratio yet at around 2.43:1. I think the photos from yesterday back this up as they look very clean and with a lot less spray than normal. here are a few pics and bits of run data.
This is what we want to see. Doing around 38 knots in 16-17 knots of wind and looking tidy.
VESTAS SAILROCKET has come a long way to get to this stage of development. We hope it translates well to stronger winds.
A nice path was sailed along the Walvis Bay speed-spot. I have changed some of the wing control systems and this allows me to stall the wing rapidly at the end of the course and thus slow down quicker. The run average was 35.8 or thereabouts.
Righto... let's have a look at some pics from the darker days just gone.
This is Run 50. The rudder has departed and we are going hard into a round-up. We went form doing 35 knots at a true-wind angle of 120 to facing backwards and stopped in a little over four seconds. that has to be a world tacking record in it's own right!
The run data from Run 50 shows the course I sailed. The lee-helm was overpowering me and I couldn't run parallel to the beach. It was getting rough out there.
The aftermath. This is how we towed our poor, wounded bird back into the shore. the rudder and aft plaing surface were both torn off. What a mess! We left all the parts over at speed-spot for the night. It was the first time we had to do this.
The next day we went and brought her back piece by piece. You can see the broken platform up on the beach over the top of the wing.
Getting amongst it! cutting out all the broken bits and getting my head around the repair.
A great local friend offered to help with the rebuild. Fi-fi is seen here making the new skeg steering brackets so as to much improve some of the systems. He says 'it's nothing', to us it is everything and much appreciated. cheers to Alan Louw for letting us use the big tools!
First re-assembly of the new transom. note that the stainless rod that fixes the aft end of the skeg (on the left) is now attached to the transom rather that the rudder(on right) bracket as before. this means the systems are completely independent. the rudder brackets are also beefed up. The new, milled-alloy steering arm can be seen on the left. All the ball joints have been custom machined by Fi-fi and the trigger system for unlocking the skeg flap has now been removed. It's in the cockpit to remove any chance of it being accidentally activated whilst sailing. The B and G sensor is now recording the skeg flap angle.
A quick and basic strength test was carried out on the repaired beam...
...And splash. We're back... and about to blow off the dust in the best possible way.
Hope you enjoy the pics... now for the video.
Cheers, Paul.
Fri, 20 Jun 08 19:29
Firstly, thanks for the comments on our come-back runs. It's nice to know that people are listening. I'll try and answer them all a bit later.
Today we were fortunate enough to have conditions almost identical to yesterday. This is a rare occurrence and allows us to accurately assess the small changes we make between runs. Yesterday I found that I was going down the course using nearly all the range of the skeg-flap steering to stay straight at speed... but there was next to no load on it. according to 'Malcs Calcs' and my Mk 1 'eyeball', this indicated that I had biased the fixed part of the skeg a little too much to make VESTAS SAILROCKET bear away i.e. the trailing edge was too far to leeward. Now we are not talking big figures here as we have to remember that we are still doing near on 40 knots and a degree really matters. The main foil itself works at around a 2 degree angle of attack at high speed!
The data we recieved of the PI RESEARCH logger and B and G sensors showed skeg-flap steering angles of up to 11 degrees. Today I dialled the fixed part of the skeg back two turns on the adjuster and left everything else on the boat identical. today at speed I saw angles of around 2-3 degrees, a top speed of 38.5 knots and a wind speed averaging around 17 knots at best. It was the best steering that the boat has ever had. the large rudder was up, the spray was down and the wing flap was mostly in. It was a very clean run all in all.
I called malc to let him know. Ideally this is how speed sailing would go... in an ideal world... One variable at a time, but as the great philosopher 'Ice-T' once said..."S**t aint like that". Sometimes the 'suck it and see' approach has to take precedent over the scientific method if any progress is to made in a realistic time-scale.
Now let's see, a quick whip through the comments...
yep Adrian, we are looking at all aspects of the wing... but we have to see what options we have left to make the existing one more benign first... or even if we really can just sail around its weaknesses. The only time it came unstuck recently was when we had a significant and totally unpredictable blow out. Of course it might happen again. Chris and the guys at AEROTROPE who did such a brilliant job of engineering the current wing are looking hard at our options. If we make a MK2 wing... it will be made with a view to a Mk 2 boat... and hence higher speeds.
There has been a lot of blah blah and not enough pics/video etc. I totally agree... but our team down here at the moment consists of Helena and I. When we bring a video/media guy down here... we need a boat builder. When we bring a boat builder... guess what? the good news is that everything has been photographed and video'd (ask the guy who stole my laptop from beside my bed whilst I sleapt the other night) and is backed up on a hard drive. Every run has a huge amount of data and it is all archived. This alone is a job for one person. Now that the boat is fixed, I'll get back onto it... and even show you the crash footage!
For the record, I think that WotRocket is great and I'm stoked that they are out there and going for it. Rivalry is a great motivator. I wonder about their concept alot... because I simply don't understand how they are going to back up the claims. I figure there simply must be more to it than meets the eye. We shall soon see.
VESTAS SAILROCKET is a peak at where we feel the future of the speed sailing will be. We still have full faith in the concept. If we ultimately need a Mk2 boat then so be it. I don't think we are at that stage yet as this little beauty still has a lot to offer. Every day we learn more and the project moves a little closer. MI, Hydroptere and WR all have limits of one sort or another... and no doubt theories on how to overcome them... we watch and learn from all of them. Aspects of one design can be incorporated into another. If WR can make super cavitating foils work on a boat with a limited righting moment... then sure as hell we can too ( of course we are looking into it irrespective of who else is doing what). It's not a new topic to anyone looking at going over 50 knots.
We haven't put out a lot of press releases recently... but this blog has always been open and honest about what we are doing, feeling and thinking. If anyone wants to take the content and use it then feel free to. we like to spread the love. We are at a stage where we like to speak with results rather than press releases. It is funny how the publics mind works though. I remember the interest we drew in Weymouth... after we had been on TV the night before! Before that moment people would just walk by as if we weren't there. Two minutes on the box and all of a sudden voila... we must be serious! When we make a significant gain... there will be a press release. I actually really enjoy writing them...but I have seen so many that turn into nothing... that I don't read them that much anymore. Anyone can make a big claim and get some easy press... and because it's on the front page with a glossy pic, a lot of the readers think it must be real and virtually a done deal. this is a very humbling past-time.
Cheers, Paul
p.s. I know, I know... more pics. I promise you ten by lunchtime tomorrow... how's that?
Thu, 19 Jun 08 20:53
Well it was with great relief that we re-launched VESTAS SAILROCKET today. The stress of what we are doing has been getting to me over the past few days. yesterday I snapped a little. A seemingly unsubstantial thing happened and it pushed me over the edge. I knew today was going to be our 'comeback' day and I felt the presure of making it go smoothly. A crash on top of a crash does not make a cake that anyone wants to eat!
the whole boat needed to be recalibrated and it was during the very last twist of a screwed thread which was to allign the whole boat... that it happened. A pin started binding up in a hole and then it quickly siezed. It had never done this before. I tried all the tricks but it refused to budge. I had no option but to apply more force... but then the carbon laminate cracked... and I knew that the clock had begun ticking between the now and the then of the next run. It was too much after a major repair. All the work done on the days calibration was ruined as whole new brackets needed to be fabricated which wouldn't necessarily be positioned where the last ones were. It meant we were rushed. rushed on an area which I really didn't want to be rushed on. We strive above all else to keep this project scientific. to change one variable at a a time, improve our understanding and eventually dial this boat into its predicted potential. What we don't want to do is just rush it back out on to the water every time to show we can come back with a mere sailing boat. Sometimes we have to compromise. This is speed-sailing and you have to grab weather windows when they come. Some times you have to use the best of your abilities to 'have a stab'. I didn't want to have a stab straight after a significant crash... so I worked... and stressed... and my mind was full of a million things that needed attention.
Walvis delivered us the perfect day. Not too light and not too strong. We did two runs in conditions that always make the boat look good. We peaked at 39 knots and all the modifications felt absolutely fantastic. All the data PI RESEARCH and BandG sensors worked brilliantly. the data will be excellent and pave the way forward.
All the stress just washed away with the dust from the repair.
It's behind us now.
Certain e-mails in my outbox will not be sent.
Aspects of the project need to be addressed... but we can do that.
Today I sailed nice tight courses with the new skeg steering system and a new method of sheeting the wing. It worked and felt good. It was with great joy that we put VESTAS SAILROCKET safely back in her soft hangar.
Meanwhile I watch the progress of the other teams chasing the 50 knot goal. For sure the Hydroptere team looks the most impressive. These guys have done the hard yards and deserve every knot they get... but nothing in this game is automatic. The other team making claims from Australia give us a few giggles. I don't think they have done 5 knots yet... but they consider themselves contenders and are rushing to call in the comissioners!
Don't get me wrong, 'they' are one of us and I also laugh at some of our own early press releases and promises. This is a loooong road. Hydroptere started as a model in 1983. yellow Pages performed extremely well very quickly... but the same team haven't managed to re-capture or improve on the record in 15 years of trying... and it has taken us nearly 4 and a half years of dedication to even post a 40 knot average! If the WotRocket team can get anywhere near 50 knots in the next year... let's say above Hydroptere's current 500m average ( which I'm sure they will smash in the coming weeks) I will sail our boat down the Walvis course naked (and it's not real warm here either)!
There it is! Claim for claim. I'm glad they are on the water and I admire their confidence. I can understand the theory behind Hydroptere, MI, Technique A' and Longshot... but that one escapes me... Maybe they are holding back on some of the real facts. If so, fair enough.
Meanwhile we will continue to push on with what we know.
All I can say is that the boat felt great... and it felt great to be truly back. We can only progress in a careful and methodical manner until we unleash the boat that we know is within.
Desire is something you want, passion is something you can not live without.
This one takes passion.
Cheers, paul.
Mon, 16 Jun 08 18:35
Well, we are back in action. Rigged and ready for sailing!
Aye yi yi... what a hectic couple of weeks.
We said we would be back in two weeks and we are.
The fact is that although the main breakages were repaired relatively quickly, it was the detail work that brought our enthusiasm to a crawl. This brought it home just how sophisticated our once humble little speed-sailor has become. Once we just had one simple rudder hanging off the back with a line from either side to steer it. Now the back of VESTAS SAILROCKET looks like it should be probing the surface of a foreign planet!!! There are sensors, skegs, rudders, flaps, fences, pull ups/pull downs... and even a good ol' bung in there to remind us it is actually a boat.
Every aspect of the boat has gone up a level. Everything is custom made and then evolved to better serve its purpose. Everything is more complicated. It actually blows me away what we have created. We have had a lot of time during the repair to reflect on many aspects of the project. I personally love this boat and know it more intimately than anything I have ever known in my life... but it must be fit for purpose.
We must share the same dream.
That means that the creature at the core of this boat must be as willing and capable of achieving the end goal as we believe ourselves to be. If it is not, then our paths are destined to part. We must remain impartial to the boat and attached to the goal. I know that the concept underlying VESTAS SAILROCKET is the future. I know it's right. I totally believe that this boat is a brilliant Mk 1 interpretation of that concept. It is the first version to live out 'Bernard Smiths' vision of a '40-knot sailboat'. In fact it is already probably the fastest boat ever to come out of the UK (perhaps unfairly excluding wind and kite surfers in this context... but for the sake of the point I'm referring to a boat and not a board).
But we are yet to see if this version is going to take us all the way to the goal. WE NEED TO FIND SOLID, RELIABLE AND CONSISTENT CONTROL! We shouldn't be punished for every little indiscretion we make either. The wing has been a handful from day 1. It is an unruly beast. One that is in it's element when blasting down the course but a handful everywhere else.
We have not exhausted the design solutions for many of our problems and continue to research them, experiment and modify as best we can. We always dreamed of getting to this stage of the program where our problems were high speed related. Well, we are here... and every windy ride is absolutely thrilling for all the team on-site. The video from our last days sailing have kept all the locals talking. I will share it all soon.
I apologise for not posting a lot of content about the repairs and decision making process but any time not spent here has been spent on re-building the boat. The fact is that we have been incredibly busy getting the boat back into the shape it now is. It has occupied my time and thoughts every conscious moment.
She has a few knocks and bruises now but she is still our pride and joy. We will give her the best shot humanly possible of being the fastest sailing boat in the world. With every scratch and modification we infuse more of our own souls into her.
The title of this post??? A great little chap from the island of St Helena came by today to help out in case we got onto the water. He has spent a great deal of time out on working fishing boats and despite being pretty young, he has already done two circumnavigations. He has a quick eye and knowledgeable understanding of what our problems are. As we finished the last intimate little details of our repairs he commented on a philosophy he once heard from one of the engineers onboard a boat he spent a lot of time aboard. Jonathon said how the engineer believed that the natural state of anything mechanical or electrical is not a functioning one. Working smoothly, as we humans desire these things to be, is not the state that they aspire to. Hence the engineer went on to say that those rare moments when everything is indeed working perfectly are actually moments of chaos and disorder that require constant outside attention to maintain. I can't argue with this logic.
So it is today... that VESTAS SAILROCKET has returned to a state of chaos and disorder... and is sitting outside once again. She is fully rigged and ready for battle. Significant improvements have been made to the skeg-flap steering system thanks to 'Fi-fi' and Alan Louwe he leant there skills and equipment to machine up some fantastic new pieces which are both beautiful and fuctional. All the play in the previous system has been removed and this has allowed us to remove certain problematic systems and incorporate simpler designs that will makemy life in the cockpit much easier.
So the last crash is never behind us until the next run vindicates our decisions and solutions.
Hopefully that day will be tomorrow. Hydroptere has begun its world record assault in earnest so the game is afoot.
I can't wait to get back out there.
Stay tuned, tomorrow looks a bit light... but we will be ready.
Cheers, Paul.