On board B&Q Castorama

Thedailysail goes for a test sail on Ellen MacArthur's new 75ft trimaran

Ellen and Nigel Irens

Ellen MacArthur's latest project is to attempt a series of singlehanded offshore record passages on board a new purpose-built boat, Castorama B&Q that is to be launched officially today in Sydney, coinciding with the opening of Schroeders London Boat Show.

Ellen has been a friend for many years with leading multihull designer Nigel Irens and the seed for this project was sown between the two of them as Ellen was deciding what to do with herself following the Vendee Globe.

Irens is one of yacht design's great free thinkers - he is best known for his 60ft trimarans such as Apricot, Fujicolor, Fujifilm and Sergio Tacchini - but has also been the creative genius behind the long skinny power trimaran Ilan Voyager (and subsequently the larger Cable & Wireless) as well as a number of modern gaffers of all sizes.

While all the trimarans Irens and his French co-designer Benoit Cabaret have drawn recently have been built to the ORMA 60ft multihull rule, with the new Castorama B&Q they were able to start with a clean sheet of paper and come up with a boat that was both free of any constraints and purpose-built for the task - namely a vessel fit for Ellen to break singlehanded records, including round the world.

"Ellen’s new project has given us the great opportunity to chuck out the rule book and simply focus on doing whatever is necessary to make a faster, safer and more surefooted boat, which we hope will allow her, in the context of record breaking attempts, to turn in consistently high daily runs, week in week out, almost anywhere in the world," says Irens. "Aside from the interest in beating records our own particular interest is in saying ‘are the 60 footers representative of what trimarans can do in the ocean or can we go one better, in terms of the ability to cover the miles in the days within a reasonable margin of safety and with a minimum amount of effort?'" Irens has been critical of the ORMA class both for becoming too stayed and for compromising the boats for their use offshore shorthanded and inshore in Grand Prix.

While a multihull is clearly faster than a monohull, a trimaran was chosen over a catamaran simply because of the more reliable stability characteristics of the former. "The righting curve of stability for a trimaran is far more conducive to singlehanded sailing because it is a far more gentle curve - it is halfway between a catamaran and a monohull," explains Irens. "A catamaran needs to be sailed right on the edge all the time which means you are either almost flipping it or you aren’t sailing it to the optimum and that is not a practical or safe proposition for singlehanded sailing."

The next problem was establishing a length of the boat. This in the end was a function of the size of sails Ellen felt she could handle with reasonable efficency. Having spent much time on board Alain Gautier's 60ft trimaran Foncia, it was decided that the basic dimensions of an ORMA 60 rig should be used.

With the rig decided upon it was then a case of working out the dimensions and orientation of the platform to go beneath it. ORMA 60s are around about as wide as they are long and this gives them incredible stability and hence power. They have evolved this way because under the ORMA rules length is limited to 60ft while beam is unrestricted. It was felt that this degree of power achieved through righting moment did not need to be increased and so because Ellen's new boat is heavier maximum beam was marginally reduced to 53ft (16.2m). Meanwhile the hulls were lengthened.

"The 60s are quite difficult boats to sail downwind in strong seas simply because they are only 60ft long," says Irens. "So there is a big problem in terms of longitudinal righting moment and potential forward-going power. That is why they are capable of 35 knots in flat water but in the ocean, in trade wind conditions for example, they turn in an almost disappointing performance of 20-21 knot averages. So they are not optimised for those conditions. So as soon as we are freed from the tyranny of a length limit we can go on and on forward with the bows and create far more longitudinal righting moment."

Hence the platform of Castorama B&Q started at around 72ft, and slowly grew to her final length of 75ft (22.9m), the majority of additional length being in her bows. While the hulls of 60ft trimarans are all roughly the same length, the main hull on the new boat is 1.5m longer than the floats simply because it much harder to structure lengthy float bows - they have a tendency to snap off.

The length has also been added in the bow as a majority of the record attempts the boat will be undertaking are on downwind courses hence the performance of the boat has been orientated more in this direction. For example the daggerboard is only 3.9m long compared to the 5m long boards found on the current crop of 60s.



Benoit Cabaret and Nigel Irens

The rig is also positioned further aft in the boat - 56.4% of the way back from the bow to be precise. Because of the additional length on the bows the forward cross beam has been moved forwards so instead of the rig being stepped on the point where the forward beam meets the main hull, it is some 3m aft of this with the daggerboard in between.

Unlike the X-beam configuration found on the modern ORMA 60s which have an additional semi-circular track slung off the back of the aft beam for the main sheet track, Castorama B&Q has two beams both with their apex facing aft. Although both were hewn from the same mould, the aft beam is slightly different in that the fairing breaks away forward as it heads for the mainhull, to form a smaller version of the modern day 60ft trimaran's elliptical cockpit. The idea is to provide less opportunity for Ellen to fall out of the back of the boat.

While Castorama B&Q is clearly longer and an narrower than an ORMA, equally evident is her increased freeboard - almost 2m at the bow. This adds huge buoyancy to the floats, reducing the possibility of pitchpoling and also keeps the beams further out of the water and makes for a much drier ride.

To make the hulls more seakindly the hull shapes are less brutal than those of a 60 footer. The floats have less volume in their ends and there is a distinct chine in the main hull as in most conditions a narrow waterline is required, but occasionally when sailing through waves large amounts of reserve buoyancy are needed.

KISS (and safe)

As the boat is designed for singlehanded record breaking and any downtime spent repairing broken gear compromises this, the philosophy behind Castorama B&Q has been to keep it as simple as possible while preparing for the most likely risks. Hence while the ORMA 60ft fleet have all manner of foils and rotating and canting widgets, Castorama B&Q has almost none of the latest go-faster toys.

There are no foils in the floats, although she is structured so that they can be fitted at a later date if need be. Beneath the waterline extreme prudency has been the order of the day as with the amount of flotsam floating around our oceans a collision with a semi-submerged object is a case of 'when' not 'if'. The daggerboard is raked aft so in theory a collision with a light weight object would cause it to drop down the bottom of the board. If the boat runs into something more substantial then there is the most almighty crash box in place to cushion the collision.

Equal care has been taken with the three rudders. The one on the main hull kicks up into the transom while the float rudders are fixed and have been structured so that the blade will snap off in the event of a collision. Ellen will carry a number of spare rudders for the floats which she should be able to fit at sea.

Above deck the rig is based on a carbon fibre rotating wingmast, but built monolithic without a core. However compared to an ORMA 60 mast the spar has a more rounded profile measuring 650mm in chord and 400mm across. This again is to increase robustness and reliability. Significantly the rig cannot be canted to weather or raked fore and aft like the ORMA 60s.

Similarly prudent has been the choice of standing rigging. Rather than fitting the current state of art - PBO - the cables for the standing rigging have been made by Future Fibres in encapsulated Kevlar. Each shroud comprises the main rod and a shorter rod attached to the deck, the two lashed together with substantial Spectra cord.

Another advantage of having elongated bows and the forestay some 2.5m inboard of the bow is that there is no requirement for an additional bowsprit from which to tack the downwind headsails. Instead there is a fore and aft track running along the top of the bow carry the tack of these sails. Ellen fits the tack while the car is at the in board end and can then haul the tack out to one of two settings along the track, where the car is held in position with a locking device, similar to a halyard lock (the mast doesn't have halyard locks).

The sails

The sails, as with all of Ellen's projects, have been put together by North France under the watchful eye of Bruno Dubois. All the sails with the exception of the small staysail (a panelled sail in Spectra/carbon) are in 3DL but Kevlar rather than carbon and with a Taffeta outer skin for added durability. The mainsail has considerably less roach - Dubois says this is roughly 10% more than a conventional mainsail, whereas an ORMA might have 20% more roach. This is partly to improve the ease of handling but also to relieve compression in the battens.

A new development in the sail wardrobe has been with the gennikers which are also 3DL - normally gennikers have too deep a shape to be moulded.

In terms of their finish Dubois says that the sails are more like a Vendee Globe suit rather than those he would normally fit on an ORMA 60 and are slightly more orientated to downwind performance.

The cockpit

The cockpit is elliptical in shape like an ORMA 60 but instead of being large enough to accommodate 12 Frenchman with a number of coffee grinders it is designed for one short Englishwoman and a single coffee grinder.

To get the ergonomics of the cockpit correct a full scale mock-up was built in Cowes. There are two helming positions to port and starboard, but these are much closer to the centreline of the boat than a 60 leaving Ellen only a pace away from her coffee grinder and all the winches. The cockpit is also relatively deep, coming up to mid-thigh height.

Down below

The accommodation layout is unique for a trimaran in that the freeboard of the mainhull has allowed two floors to be built in it. Entering from the cockpit there is a cuddy area where Ellen can sit protected from the elements. Inside from here the cabin is at the same level as the cockpit with the chart table immediately forward - like an Open 60 (and substantially larger than a 60ft trimaran's nav area) with a bunk to port. The chine in the main hull provides a maximum beam of 2.7m - much more than a 60footer.

"The floor is above the waterline, so from a warmth point of view if you go anywhere cold it is a shedloads better, because with a monohull the whole hull is sitting in pretty cold water," says Ellen.

Crawling forward there is another compartment with two escape hatches and allowing easy access to the electronics.

On the floor below there are two engine rooms - one for the main engine, a 75hp Yanmar and another for the generator. The freeboard in the main hull is such that Ellen can stand up in the basement of her trimaran. The main engine will be taken out for long records, but for training will stay in there because it represents the same weight as the fuel you would carry for a long record.

So what's she really like?

Someone sailing in another regatta here in Sydney genuinely said to us - "did you see those two trimarans out sailing today?" An easy mistake as the boat if viewed from the starboard side is orange and white and called B&Q, while if from the port side is blue and called Castorama. Both B&Q and its French equivalent Castorama are hardwaare store subsiduaries of Kingfisher.

The general impression of the boat is that she is a less beamy, longer, pumped-up version of an ORMA 60. When we sailed her it was in 15-20 knots of breeze mainly around the entrance to Sydney Harbour under reefed mainsail and jib and then staysail (unusually the jib - apparently an abreviation for storm jib - is on the inner most stay, the staysail on the middle stay).

While we hit 18 knots coming back down the harbour the crew were loath to risk the boat by pushing it prior to the all-important naming ceremony coinciding with the opening of Schroeder's London International Boat Show. However saying this they had hit 28 knots during a photo shoot the previous week. The real work up of the boat will take place after she has been delivered to Auckland in two weeks time.

Off the Sydney Heads the sea was reasonably lumpy and occasionally a wave would slap against the underside of the floats causing a jarring shock wave to pass through the boat. This is normal trimaran behaviour but it was interesting that the shock wave didn't oscillate around the boat to anything like the same degree as an ORMA 60 - proving her beefier structure (more on this tomorrow).

The cockpit seemed crowded for a full crew, but looks like it should work a treat for Ellen when she is alone. All lines lead aft to the cockpit with the exception of the genniker halyard which is operated off a winch on the mast. There is a particularly clever barber hauler arrangement for the headsails - a flying block is supported by a long piece of bungee attached to the mast and has up and down and athwartships controls. Normally on 60ft trimarans the headsail fairlead is mounted on the forward cross beam but this is not possible on Ellen's tri because the front crossbeam is too far forward.

At present the boat is still very new and still has much work to be done on it - for example the generator still has to be fitted as has the chart table seat and the two helming seats in the cockpit. 60ft trimaran-style windscreens are also going to be mounted in front of the helm stations.

Tomorrow we get Ellen's views about her new boat and its program, look at her ground breaking construction and engineering and some of the innovations on board her.

See more pictures of her on the following pages