Pushing the boundaries with Sodeb’O

At 105-foot long, Sodeb’O is one of the most ambitious and technologically advanced trimarans ever built. That’s not even taking into consideration the fact that it has been designed and built for a crew of one!

Thomas Coville plans to make an assault on the singlehanded round-the-world record set by Ellen MacArthur in February 2005 in her purpose-built 75-foot trimaran, B&Q. It was a phenomenal performance, and it will demand excellence from Coville in every aspect of his campaign, if he is to have any chance of beating B&Q’s time of 71 days and 15 hours.

One area where there have been significant developments over the past three years has been in rigging, and Coville has been working closely with composite rigging specialists Future Fibres in producing something that will support his 35-metre carbon rig safely around the world through all conditions – but for the minimum possible weight.

PBO rigging is beginning to take over from Kevlar as the preferred option on these types of boats and the original plan was to fit out the entire Sodeb’O rig with PBO. With the Nigel Irens / Benoît Cabaret design having been built in Australia at the Boatspeed yard, Coville and a small crew sailed Sodeb’O back from Australia up to Europe.

The semi-circumnavigation was also an ideal opportunity to test the possibility of using a full complement of PBO rigging. Miles Amin of Future Fibres explains the rationale of the project: “Becoming technical partners with Thomas and the Sodeb’O project has been an excellent learning curve for both parties. Historically the big multihulls have used Kevlar rigging. PBO hasn’t been perceived as suitable on maxi-multis because of the extreme shock loading that can occur in this type of extreme sailing.

“But there was a lot of rumour and word of mouth about the pros and cons of these different types of composite material, so Sodeb’O’s journey from Australia to France was an excellent opportunity to get some hard facts. We could put some cables on the boat and carry out a full programme of destructive and non-destructive testing.

“We already had a fair idea of PBO’s strength under static loading, but predicting dynamic loading is a black art, which is why this trip was so valuable to us. We wanted as much information as possible from Thomas, for example how long they had been on port/starboard tack, in what wind strength and wave conditions etc. We wanted to know what sort of treatment the cables had seen.

“When we got the cables back, we found that in some cases the cables had been cycling at a higher percentage of their break load than we had expected. That was a bit of a surprise. Whereas we had expected the cables to be cycling at 10-25% of maximum break load, the figure in some cases was more like 25-45% of the cable’s UTS (ultimate tensile strength). The cables were coming on and off load more often and more aggressively than we had thought.

The aim of the exercise was to analyse what had worked satisfactorily and what had not worked so well, and then to upgrade or up-spec the cables where needed.”

“The majority of rigging is staying as PBO,” says Amin, “with a few elements being made in Kevlar. When Ellen went round on her record-breaking voyage, B&Q was rigged with a full set of Future Fibres Kevlar rigging. Things have moved on in the past three years, and if Thomas is going to have a chance of breaking that record, he needs to move the game on in every area. We believe that for this project he is using the most optimised set of rigging ever produced.”

Amin acknowledges that other campaigns may be using an equivalent, lighter set of PBO rigging, but that such an approach wouldn’t be appropriate for Sodeb’O. “When you’ve got a fully-crewed multihull, you’ve got 14 pairs of eyes to keep a good watch on what’s happening. It’s easier to keep things maintained, and you’ve always got someone steering, watching for the gusts and the waves. Thomas is not going to spend much of his time at the helm – and of course he’s going to need to sleep! So the set of rigging we have produced for him is the lightest and strongest we could make, whilst also providing that safety factor to give him peace of mind that this rigging will get him around the world.”

Coville is looking at making an attempt at the singlehanded round-the-world record sometime in the next few weeks.

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