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2006 - second half

2006 - first half

2005 - second half

2004 - second half

2004 - first half

2005 - first half

26 June 2005

It was great to have the chance to return to the Pacific Northwest for a better look, and with the family this time. We all found something to enjoy in the region and, although I normally hate big cities, I was knocked out by Vancouver. The trip was part business and part pleasure, and I appreciated the opportunity to discuss the ROCAT with active open water rowers thereabouts. One such, who is determined to have one of the first ROCATs off the production line, invited me for a row out of the very active Jericho Sailing Club. He has his own Hudson, but the club has a number of Alden, Maas and Echo openwater boats for the use of members – I decided to try the Echo. This would be the first time I'd rowed a 'monohull' rowing boat for very many years, and I approached the beach launch with some trepidation! What an interesting and valuable experience that row was though – we only rowed about 1 1/2 miles (in deference to my near novice status), but I stepped out of that boat at the end quietly jubilant – this short row confirmed the efficacy of many of the improvements embodied in the ROCAT which were based on a fairly distant recollection.

This is in no way a criticism of the Echo which appears to be a very good boat of its kind. I was impressed with the build quality; it runs well, and incorporates a number of really neat design details – the way the riggers unfold and lock, for example, is especially ingenious – I just happen to think that it perpetuates an ancient, flawed system.

On this trip to British Columbia and Washington I encountered a refreshingly positive attitude towards innovation and new products, compared with what I'm used to in the UK. A great deal of my time over the past five years has been spent trying to raise funds to develop the ROCAT, but the response has generally been "sorry, much too risky; come back in a couple of years when you've got some solid sales figures"! Britain is good at producing innovators, but notoriously bad at facilitating the development of their ideas – perhaps the struggle is good for my soul!

In my absence, Anthony made a good hull and a roof-mounting-system tray for the seatdeck – and Rojac machined the plug for the bottom crossbeam mould ... CL

Echo open water rowing shell Echo's rigger new crossbeam plug

27 May 2005

At last, I've got the CAD model (below in the VX CAD/CAM program) off to Rojac for a quotation for machining the new crossbeam moulds. I have also (finally) got an evaluation copy of ProENGINEER. Both VX and ProE have come a very long way from their (difficult) UNIX origins and they are both (relatively) easy to use and very capable. The more I see how good other CAD apps have become, the more I wonder at think3's extraordinary price hike.

The next picture is of the new mould for the outside of the roof-mounting-system seatdeck tray, followed by a reminder of why it had to be done again – the mould release agent failed to release and the previous mould, together with the freshly infused and cured part, had to be scrapped. I have, BTW, been asked not to name the product until the manufacturers have properly investigated the cause.

The fourth picture shows thickness wax being applied to the mould before laying up the inside mould. The wax is the same thickness as the fibreglass in the finished part so, when it's removed, there is an appropriate cavity between the two moulds.

In the meantime, my glimpse of the Pacific Northwest in February was enough for me to want to return, but I didn't expect that it would be this soon – my wife and two (grown) children wanted to see the place for themselves, so we are taking a12-day break there next month, splitting our time between Vancouver, Seattle and Victoria. While I'm not yet in a position to bring a demo boat, I would be very happy to meet anybody in the area who would like to discuss any aspect of the ROCAT ... CL

crossbeam CAD new mould for seatdeck roof-mounting tray seatdeck tray mould wrecked waxing up the new mould

12 May 2005

This project could not have happened without CAD (Computer Aided Design) and, over the last few years, I have spent a great deal of time sat at my computer. I always work out the concepts first 'by hand' in my notebook. Then I model the shapes in CAD on screen before sending the CAD files off to Rojac Tooling Technologies in Wednesbury. There, computer-controlled machines realise the shapes, and composite moulds are taken from these 'plugs'.

The ROCAT was designed using a program called 'thinkdesign', published by 'think3'. When I first got thinkdesign, think3 made a feature of the fact that it was only available on subscription. This suited me well at the time as I didn't have to find the high upfront cost of buying and it was reasonably priced – it was also a very good program – but things started to go wrong when they pulled out of the UK leaving us without support. Since then, think3 appears to have taken leave of its corporate senses and, absolutely counter to the industry trend, they have substantially increased the price of the thinkdesign subscription. I have enjoyed using this product, and will be sorry not to renew, but it's definitely not worth what they are asking. The trouble is, there are very serious ramifications to leaving – when your licence runs out, you can no longer access your think3 files! It simply didn't occur to me when I signed up 4 years ago but, if they were to explain that carefully to prospective customers, I wonder how many new deals they would close? At the very least, they should provide a utility to open the files, and convert them to a generic file format like IGES or STEP.

So, over the last couple of weeks, I have been evaluating a number of CAD applications, and I've found the process very interesting. On the functional side, similar end results can be achieved in a number of different ways and, ultimately, it's down to which programmers get closest to one's preferred workflow.

But there's another aspect of CAD purchase with which I have a REAL problem, and that is a pricing policy that so cruelly discriminates against UK residents – a product which costs 4,995 dollars in the USA, sells for 4,995 pounds in the UK! Has nobody told them that a pound is, currently, worth nearly two dollars – why on earth should we have to pay almost twice as much as the US residents to buy these CAD programs?! It's not right! And it's all so clandestine too – try to find the cost of CAD on the internet and you'll find that Value Added Resellers prefer not to publish their prices?! Why has the UK CAD market has tolerated this unfair trading for so long, and how many seats would they sell in the States at almost $10,000? It's all very strange.

Confucius could have said "companies who piss on their customers (or potential customers) breed great resentment".

Changing the subject, I had a preliminary report from the manufacturers of the mould release confirming that the returned sample of release agent failed to release for them due to moisture contamination – I await, with interest, there explanation as to how this might have occurred. Meanwhile, Anthony has been rebuilding the mould from scratch.

A regular correspondent marvelled at a) Allyson sitting in the ROCAT on dry land and b) the boat parked up on the shore and slips on the Helford estuary excursion (1 May below) – "This is something that we would never do with sculling / rowing boats as they're just not robust enough to support on trestles and then sit someone in".

In the absence of other reference, it's entirely natural that existing rowers will extrapolate their conventional sculling experience on to the ROCAT – but, except for the fact that they are both 'rowing boats', they are not the same!

The first picture below is of Anthony (who is 97kg / 214lbs) demonstrating the strength of a ROCAT hull (which only weighs 8.5kg). The second picture (from the archive) demonstrates the extent of the ROCAT's reserve buoyancy ... CL

demonstrating hull strength demonstrating reserve buoyancy

5 May 2005

Time to mention 'Unlocking Cornish Potential' and 'Objective One Funding'.

Cornwall, being one of the poorest regions in Europe, gets 'Objective One Funding' which is pumping some 300 million pounds into Cornwall to improve its prosperity. Naively, I imagined that a tiny bit of this might be made available to help a new job-creating manufacturing company off the ground but, clearly, I don't understand how these things work.

But we have benefited from a small, really useful, OOF project called 'Unlocking Cornish Potential'. This has been set up to encourage businesses to take on graduates by subsidizing their salaries and, when Anthony joined ROCAT, he was one of the first graduates placed under this scheme. UCP provided assistance for one year and, yesterday, Allyson Glover (UCP's Project Manager) came down to sign Anthony off.

Although she has never rowed before, she has often expressed an interest in trying the ROCAT, so this seemed like a good opportunity. I was also curious to see a) how a complete novice would take to the boat and rig, and b) how it would work with someone 162 cm (5'4") tall.

After a brief run through on dry land, Allyson set off with a will and did very well.

Once people start racing the ROCAT, competitors will pay careful attention to the finer points of the stroke, but I have found that it's best to have the arms locked out straight during the whole of the leg-extending power stroke. Then, when your legs are flat, you finish and feather with your arms. Those unfamiliar with the ROCAT stroke will find that strange, but the oar handle is stationary during the power stroke and your arms could, in fact, be replaced by a strap around the back of the seat.

Allyson was inclined to pull with her arms too soon, and that's a tendency I've noticed with several people when they first get into a ROCAT. Perhaps the strap would be a good training accessory (not for chastisement!) – it would show that your arms are only anchors while your much more powerful legs do all the hard work. Allyson's stature was not an issue and she said she would like to have another go soon.

Meanwhile, someone wrote in to ask why I didn't use a GPS on the Helford trip. The simple reason is that I don't have one, but I do recognise that it would be a very useful accessory, and I suspect that it's something that we will offer, with an appropriate mounting. I had thought that we might fit a compass as standard, but that would be wasted if you have GPS; anyway, it's time I got up-to-speed with sat-nav technology ... CL

UCP project manager, first time rower UCP project manager, first time rower UCP project manager, first time rower UCP project manager, first time rower
ROCAT in small chop ROCAT in small chop

1 May 2005

Have moved webhost to NetPivotal; they offer more for less than the previous lot – the transfer apparently occurred efficiently without hitch. So far, so good.

The manufacturer of the release agent that failed, could offer no immediate explanation. They did observe that, because the product is sprayed on, it just sits on the surface and it's more important that all vestiges of compounding wax are carefully removed before applying the release. With wipe-on releases (like the Frecote we have been using) the act of wiping it on disturbs and cleans the surface.

It's 'bank holiday weekend' in England, and I decided to take the boat 15 miles east to the Helford Estuary to try it in a different setting, and do a bit of what Americans call 'gunkholing'. I was going to launch off the beach at Helford Passage, but baulked at the 8 pound launch fee. The Falmouth Harbour Authority also charges 8 pounds to launch, whether it be a 30ft motor gin palace, or a single-seater rowing boat! The harbour master could not see the oddity of this, and it occurs to me that launch locations could well be quite an issue for the ROCAT – perhaps, when the boat's in production, we could add a page to the website (or forum) for ROCATeers to post recommendations and warnings.

Anyway, I back-tracked to Port Navas and used the 'free' public slip (1st pic). Very soon, as I weaved through the moored boats, I regretted not having fitted some mirrors. I have never understood why all coxless rowing boats are not fitted with these useful devices – I get the impression they are even regarded as a bit sissy, especially on sculling boats?! A pair of slightly convex mirrors will be fitted as standard on the ROCAT.

The sun shone and I was headed by a stiff breeze as I rowed, in a leisurely fashion across, the estuary to Helford. There I pulled up and went for a pint of excellent beer and a smoked mackerel 'ploughman's lunch'. (In case you are wondering what this has to do with an account of the development of a revolutionary rowing catamaran, I do have to research all its likely uses!)

I then rowed east almost to the sea; back across the estuary and back, past some very pricey properties, to Port Navas. There, I landed on the 'Port Navas Yacht Club' slipway. In spite of its grand name, the PNYC is a small, friendly, bar-restaurant with moorings. Visiting yachtsmen are welcome, and they stretched a point for this visiting oarsman.

I must dig out my chart of the area, but distance rowed was probably 7-8 miles, and the boat worked just fine. In fact it was a very pleasant way to pass the time, given that I was working! ... CL

launching from Port Navas public slip Helford Estuary Helford village
properties on the Helford Estuary returning to Port Navas Port Navas Yacht Club slip

27 April 2005

Talk about ups and effin downs!

Went out on the boat this morning. The weather was just right – bright sun with a brisk westerly breeze to put some bumps on the sea. We wanted to test the new skeg and swingarms, and they both worked well. The strong yoke and new swingarms have practically eliminated the disconcerting bounce at the rowlocks and, for the first time, proto 3 began to feel as solid as the old boat. The skegs are only small, but they make a huge difference to the boat's tracking, especially 3/4 to the wind, where the proto 2 would tend to round up.

When Anthony had his go, he moved downwind of the breakwater for shelter, turned and let rip for about 50 metres. I was really sorry I didn't have a video camera because I've never seen the ROCAT move so fast! The first thumbnail links to a sequence shot, which was the best I could do. The third picture shows the size of the skegs in relation to the hulls.

Meanwhile, the seatdeck roof-mounting system tray mould was finished yesterday, and we decided to infuse a part. The process went smoothly and, after an overnight cure, I went into the workshop this morning expecting to demould this simple shape with ease – but it wouldn't budge. On our return from the row, we both set to, surprised that there should be a problem. When all attempts to remove the top mould failed, we decided to cut it off, hoping that we would at least have a usable part, and a sound bottom mould. As the last picture below shows, that was a forlorn hope, and we have had to scrap the whole thing!

So what on earth went wrong?

We had been recommended a different semi-permanent release agent, and were trying it for the first time – for some reason, it just didn't work. Anthony followed the application instructions to the letter, but I suspect there must have been something on the mould that it didn't like. I must find the cause – and will shed a tear or two for all that wasted work and materials ... CL

sequence of the ROCAT at speed proto 3 on the slipway proto 3 on the car showing the new skegs seatdeck tray mould wrecked

24 April 2005

I wish I had time to get the forum operational so that the emails I get could be part of an open discussion.

My "(intended!) flexibility" comment (10 April below) brought some comments from some folk who associate flexibility with weakness. Absolutely not so!

I believe, strongly, that rowing catamarans should be as flexible as the medium they are riding on. People often try to extrapolate their experience (or observation) of high speed sailing catamarans to a rowing boat, without appreciating the differences.

A Hobie, for example, needs to be stiff in order to support a rigged mast vertically – any 'working' of the hulls puts terrible strains on the rigging.

Without that constraint, though, the ROCAT can be designed to flex freely and move with the waves. In a quartering sea, the diagonal loads on a cat are enormous, and a 'stiff' boat has to be extremely strong to withstand those loads. But if the boat is designed to be flex in the right way, the hulls remain in contact with the water and those loads disappear – the boat can then be significantly lighter.

The carbon fibre crossbeams are very strong in bending (to support the weight of the rower), but they have quite low torsional stiffness, so the hulls can flex. This, incidentally, also reduces the loads on the crossbeam mounting points.

Parallelograming, on the other hand, is an undesirable feature and this is prevented by the shape of the crossbeams, and the way they join the hulls.

I have also been asked, BTW, how one would right a ROCAT when it turns over! This is a fine example of false logic. A sailing catamaran can be made to capsize – the ROCAT is a catamaran, so it can also capsize. But the sailing boat is driven at high speed, and it has a tall mast to help topple it. In fact, the ROCAT behaves more like a raft. You can jump up and down on one hull, and there is no reason for the other hull to lift out of the water. And before you ask, 'but what about broadside in a breaking surf?', the boat's not designed for that, so I've no idea ... CL

10 April 2005

Here are some of the scanned pictures.

The first one is a long lens shot of the ROCAT with St Michael's Mount in the background. The next two are interesting because they clearly show the ROCAT's (intended!) flexibility. And the last two show the main advantage of a fixed seat – see how flat this short boat (by sculling standards) rides at the extremes of the stroke. Picture five also shows that Anthony has very long legs.

When I laid out the dimensions of the seatdeck and rigger etc., I got hold of detailed world anthropometric data – it's actually interesting; I seem to remember that the Dutch are the tallest, and the Poles have the longest arms! I reckoned that it was unrealistic to make a boat that would fit absolutely everybody, so I settled on a 98 percentile fit. Then along comes 1956mm (6'5") Anthony who finds the track, on which the footbar rolls, is a tad short. The anodised aluminium extruded track was already a cause for concern. There are pictures of it in the archive but it's like a C lying on its back, and the footbar 'car' wheels roll on the inside. It works very well and was manufactured with a heavy-duty black anodising to make sure it would last. However, even with its limited usage, tiny nicks and scratches are already beginning to corrode unacceptably. I am now looking for a standard pultruded, or pulwound carbon fiber section that I can buy in, and cut to length ... CL

long lens shot of the ROCAT with St Maichael's Mount behind proto 3 at sea proto 3 at sea
proto 3 in the harbour proto 3 in the harbour proto 3 in the harbour

9 April 2005

While I work on the CAD for the new crossbeam and yoke moulds, Anthony has been producing a mould for the main part of the seatdeck car-roof-mounting-system. As it's such a simple shape, we decided to skip the plug stage and fabricate the inside mould out of MDF. Once again, even for such a basic part, we will use vacuum resin infusion in a closed mould, but this time with a thin outside mould. This method is sometimes called RTM light and the outside mould is, in effect, a hard reusable bag with built-in seals and vacuum clamping. Pictures 2 and 3 below show Anthony applying the 2.5mm 'thickness wax'. When we lay up over this it will produce a pretty precise 2.5mm cavity between the inside and outside mould. The part will be made using a random mat glass with integral infusion medium, such as Saercore or Rovicore. While these materials do cost more than plain random mat, they are easy to use, they conform remarkably well to double curvature, and there are no 'consumables' to chuck and waste.

A number of people, who laminate GRP parts without a second's thought, seem to be strangely in awe of the mould-making process. Neither I, nor Anthony, has had any formal training in composites, but we are both 'good with our hands' and endowed with a certain amount of common sense – the process is really not as difficult as some would make out!

The bottom pictures show further development on the skeg. The first skeg we cast using one of Atlas Polymer's ultra-tough polyurethane casting resins was extremely strong but, at 424 grams (15 oz), far too heavy. In producing this boat, we are fighting a continuous battle with weight. It's so easy to think that the odd 100 grams here and there are not important, but they add up and the target weight is the sorry victim. For the boat to be truly usable by women and men, small and large, it has to be AS LIGHT AS POSSIBLE – without sacrificing strength.

So Anthony lined the skeg mould with 3.5mm wax and cast a silicone insert. The second casting, using this to make the part hollow, weighed 234 grams (8 oz), and still seems strong enough – testing will tell. The bottom tip has 12mm of resin to withstand slipway launching.

I found an unprocessed film the other day and took it in – turns out it has some pictures of the last time proto 3 was in the water, so I must try to remember how to scan the negs in order to post the pics in the gallery. How quickly I have come to take the instant availability of digital images completely for granted! ... CL

mould for the seatdeck mounting system tray thickness waxing the seatdeck mounting system tray mould thickness waxing for the seatdeck mounting system tray mould
skeg development skeg development skeg mould with silicone implant

27 March 2005

"What was the problem with the existing oars? What made you decide to build your own?"

... one obvious reason is that, once developed, it will cost significantly less to make our own oars than buy them in. But there's more to it than that.

In devising the ROCAT I have tried to take a fresh look at rowing and examine every aspect to see if it might not be improved. For the most part that's not been difficult as, apart from the use of new materials, the design of fast rowing boats has remained pretty static for over 100 years. I know this is largely down to the governing bodies' resistance to change, but the fact remains ...

Oars changed a bit relatively recently with the production of filament wound carbon tubes – but most of the loads on an oar are in one direction, so why use a tube that is equally strong in all directions? In that respect, the old wooden oars were much more sophisticated in their construction, with the use of ash on the leading edge to take the compressive loads – I have taken a similar approach in the design of the ROCAT oar. I have also looked at the handle, which will be cranked slightly and shaped to fit a human hand, and the blade. Strange how little seems to be known about exactly how a blade works through the stroke – given the number of universities who are keen on rowing, you would have thought some serious research would have been carried out on the subject by now; apparently not. Meanwhile, I have abandoned my attempts to get a 'rowlock' to work satisfactorily with the ROCAT rig, and have designed a ball joint to locate the oar precisely while allowing all the degrees of freedom that it needs.

It's one more thing but I believe that the resultant product will work better than the existing solution. And, as I fully expect the ROCAT to be around in 25 years time, it's worth putting in the effort now to get it right – even if I do get very frustrated at the slowness of the progress ... CL

26 March 2005

For the stroke to feel secure, the swingarms and their mountings to the seatdeck, have to be very stiff. But how do you quantify that? I only realised how stiff the first prototype was, and how important that was to the stroke, when I felt the flexibility of proto3. The addition of the carbon fiber 'yoke' across the seatdeck improved things on the water, but there was still too much bounce in the oar – this was virtually eliminated when we added a strut to the swingarm. Hmm, that swingarm looks so elegant, but is not up to the job and must be redesigned – I was expecting too much of the carbon fibre and still have a lot to learn about the strength of the materials that I'm using.

Ever since I first saw an FEA (Finite Element Analysis) program demonstrated, I've wondered how much time and money these impressive strength analysis programs would have saved the project. They are expensive but, in theory, by testing the strength of everything before you have your moulds made, you increase the chance of getting it right first time. But the trouble is, in order to do that, you need to know how strong the part needs to be, and the only source of that data is guesswork – to the best of my knowledge, nobody has quantified the XYZ axis loads on a rowing catamaran oar pin in a 1 metre swell. And anyway, how stiff is stiff in those circumstances – you've really got to get out and try it and, with experience, you know what feels right.

So the old elegant swingarm is to be superceded by the new 'will look just fine in context and do the job' mark 2 – Anthony shaped a couple up with different layups
to compare, and external bagged them (hence the imperfect finish). They are much stiffer!

The other pictures are of the proper pre-production seatdeck with which, except for some improvement to the paint finish, we are now happy. That's the hulls and seatdeck sorted then, so that just leaves ...

Our experiments with casting resins for the skeg lead to a visit from the Atlas Polymer representative. There are lots of different two-part liquid poured casting resins, and they are amazing – we will definitely use them to make the skeg and I'm now wondering what else we can make this way.

It only seems a minute since I was wishing regular readers Happy Christmas, and now Easter is upon us – Happy Easter! ... CL

the new stiffer swingarm seatdeck seatdeck seatdeck

14 March 2005

I've been asked about our ultra low-tech foaming system –

We were trying to make a swingarm foam blank in the normal way by mixing up the two polyurethane foam liquids and pouring it in the mould. This method works after
a fashion, but the results are inconsistant and not very good. This time though, we noticed that foam had escaped from the one swingarm mould into the other through
a very small gap, and this foam was smooth and creamy and even.

So we began a series of experiments which resulted in our present system, (illustrated below). First, a number of 6mm (OD) plastic tubes are fixed at one end into the top edge of the mould cavity, and the other end into the lid of a pop bottle.
We then pour the mixed PU foam liquids into the bottle and screw on the lid. The expanding foam is forced through the thin tubes into the mould cavity, and a nice, even-textured foam part results. BTW, we are using Techsil 6098L aerosol mould release, which works very well.

I have also been asked about the materials we are using, and where we get them –
I've added a materials and suppliers section to the links page, and will add to it over the next few days
... CL

producing a crossbeam foam blank producing a crossbeam foam blank

3 March 2005

We infused another seatdeck on Tuesday, and demoulded it yesterday. The infusion went very well and, apart from a few small voids, the part is good. Spraying the epoxy primer into the mould before infusing (instead of gelcoating) is working really well, and those voids highlight one of the main advantages of painting over gelcoating – while it is a small task to fill and flat those little holes before painting, invisibly blending in a gelcoat repair is a pain.

Rojac brought back the footbar foam mould and took the hull mould away to install some lateral registration and repair some cracks. Anthony immediately prepared the footbar foam mould and, where the experts with their fine foam-blowing machines had failed, he managed to pulled a near-perfect foam blank with our ultra low-tech system!

I have recently subscribed to 'Rowing News' and am well impressed with its content and design – so much so that I ordered a dozen back issues to get a more thorough background on the North American rowing scene. Well done to the publishers and staff of the magazine ... CL

1 March 2005

It occurred to me this morning that today is the fifth anniversary of the official beginning of the ROCAT project!

Hmmm – I wonder if I would have set out if I'd known the road would be so long,
steep and rocky?

I heartily thank those who have supported the project, and have encouraged its continuation when encouragement was needed ... CL

26 February 2005

The first picture below is of the first pull from the new skeg mould, tacked in place to see how it will look. Its depth is nearly the same as the hull's max draft, which is in the middle, under the front crossbeam.

The second picture is of another crossbeam infusion – it's better than the last one,
but still not right. Sometimes things go right first time, and that feels SO good, but mostly development is about quite small incremental improvements, and the pace can be very frustrating. I just have to remind myself that this kind of innovative idea-to-market product would normally be handled by a substantial team, (with plenty of resources at their disposal) and that we are not doing too badly for just the two of us.

I have received emails from people with ideas they want to develop into marketable products – 'how do I go about it?' – my strong inclination is to tell them 'don't even think about it!'

Just got a new webstats program – Statcounter – which provides a lot more detail than the Webalizer provided by the web host. Webalizer reports that this unpromoted, unsophisticated site received 48,800 hits from 1,695 visitors so far this month – Statcounter tells me where you all are; how you found your way around the site (or didn't); how long you spent, and whether you've been before etc. etc. – better than tele, except that I don't have time to watch that anyway ... CL

first pull from skeg mould tacked in place carbon fibre crossbeam

18 February 2005

There are a lot of very beautiful places in the world – Cornwall is undoubtedly one, but the Pacific northwest of north America is certainly another. My schedule was packed to the minute, but enjoyable and very rewarding. Thank you Sound Rowers, and all the other good people I met, for your warm hospitality and valuable information on the WA and BC open-water rowing scene.

If I remember correctly, there are 16 rowing clubs in the vicinity of Seattle – I was intrigued to find that, just a few miles north, around the geographically very similar Vancouver and Victoria, there are (as far as I could find) just 3 clubs.

Back to work, we have decided to go for a fixed skeg and Anthony has hand-shaped an excellent plug. We have successfully blown foam blanks for the front and back cross-beams and will infuse those as soon as we get the carbon braid from Eurocarbon. While I have begun work on the CAD for the oar moulds, and produced yet another update to the business plan, Anthony has prepared the seatdeck mould for another infusion. This will incorporate the lessons learned from the last pull, and should be a 'production quality part'.

I have had several scullers email me about the height of the ROCAT seat above the water. I understand that this is important in a conventional sculling boat because you cross your hands and have to have room to clear the oar handles over your thighs on the return, but this is really not an issue on the ROCAT because you don't cross your hands (as can be seen in the rigger animation). Hmm, I've just noticed that that animation isn't quite right – your hands, stationary during the power stroke, should
be outside your knees ... CL

plug for skeg plug for skeg

29 January 2005

Next Tuesday ( 1st February) I am setting out on a fact-finding trip to Seattle, WA
via Boston (where my brother lives). From my research so far, it would appear that Puget Sound is one of the most active open water rowing locations in the world,
so I decided it was time to visit.
I shall also be going to Vancouver/Victoria BC, and Newport Beach CA, but San Francisco, another active open water centre, will have to await the next trip. I'll be back on the 12th Feb.

Anthony will be taking a well-earned break in some snow at the same time ... CL

28 January 2005

Having cut the crossbeam foam blank longitudinally into three, we sleeved each piece in carbon fibre braid, and placed them in the mould. The top half of the mould was closed and the part infused with epoxy resin.

A few days ago I said "as long as you site your resin-in, resin channel (if it's needed) and vac-out well, you will get wonderfully consistant parts with no mess or bother"

Sometimes this is pretty obvious, but with a complex part it can take a little bit of trial and error – as in this case! The crossbeam resin channels are formed by grooves in the foam and, as the part was dry in some places, we will relocate these grooves and make them slightly bigger and longer.

The cross section (below) shows the very strong integral webs created by making the cross-beams in this way ... CL

crossbeam layup using carbon fibre braid crossbeam layup using carbon fibre braid crossbeam demoulded Cross-section of crossbeam showing foam & webs

26 January 2005

The development process can sometimes be tough! Having successfully infused a smart seatdeck, one is somewhat disinclined to attack it with a jigsaw, and cut it into bits – but we needed to know the laminate thickness throughout and the quality of infusion, so that's what had to be done. We learned some valuable lessons, and the next pull will be production quality.

And by dogged persistence, and some good fortune, we have managed to cast a crossbeam foam blank of remarkably high quality, using a very low-tech process.
Tomorrow we will have another go at infusing a crossbeam – regular readers will know that this has been the most problematic part, so fingers crossed!
... CL

seatdeck cut up for detailed examination seatdeck cut up for detailed examination seatdeck cut up for detailed examination successful crossbeam foam blank

23 January 2005

We infused a seatdeck yesterday. As the first pull from this mould (just over a year ago) was about 88% right, we have not seen it as a problem part – it uses simpler, more conventional closed-mould technology. Anthony has modified it a bit to smooth some corners and remove some unwanted details, and the infusion went just fine.

Anybody who is still making composite parts the old way, because that think that vacuum resin infusion is too complicated, or risky, or whatever, really should try it.
All our parts will be made this way and, as long as you site your resin-in, resin channel (if it's needed) and vac-out well, you will get a wonderfully consistant part with no mess or bother. It will be even better when we can afford a resin mixing/injection machine.

This is the first part that we have made spraying two-pack epoxy primer into the mould, instead of gelcoat. It released very easily (using Frekote 770N) and will need very little preparation after the removal of the flash ... CL

successful seatdeck

18 January 2005

It's great when something goes really well!

Some months ago we took two rough moulds off the seatdeck plugs. The Seatdeck is made from a clever glass material which has a high spec random glass matt either side of a fluffy mesh, which transports the resin inside the closed mould. We are evaluating three different kinds – I think Rovicore was the first and is the one being used in the pictures below.

The purpose of the rough moulds is to 'preform' the glass so that it can be shaped and trimmed before it goes in the proper mould.

And it works! I'm especially impressed at the extent to which the Rovicore conforms to quite tight double curvature in the preform mould ... CL

ROCAT seatdeck preforming tool seatdeck preforming tool seatdeck preforming tool

4 January 2005

Elsewhere on this site I describe how the ROCAT will be an 'International-One-Design' for the purposes of racing. A number of people have emailed me about this and it has also occupied a good deal of discussion time here.

Why IOD, and what does it actually mean?

While many owners of ROCATs will not be the slightest bit interested in racing, I have absolutely no doubt that competition (of one sort or another) will be an important part of the ROCAT scene.

The main purpose of making the ROCAT a one-design is to prevent the purchase of competitive advantage – if every boat is just the same, the racing is between the rowers and not the boats – but where do you draw the line? Is the whole boat locked, or just some key components?

We haven't got the forum going yet, but I would be really interested to get your feedback on this using the 'email' link above ... CL

3 January 2005

I wish all readers of this page a healthy and prosperous 2005 –
meanwhile, can anybody tell me where 2004 went?! ... CL