How big and how fast could a design go? It's a fascinating spiral of calculations, including money. Check this out

How long will it be before the
fastest round the world record is broken again? Could it go down to down to 40
days and be beaten by an even bigger multihull than the 130ft Banque Populaire
V?


The answer to both is a qualified
yes. It’s possible. But the margins are getting smaller, the risks higher, and
the huge sums needed are in shorter supply.




This round the world record time
may stay for a while. It is the first time in over a decade that another
potentially faster vessel has not been in build as a record time was being
broken.




Banque Populaire cost €14 million to build and it took four years to achieve
the end objective. Meanwhile, running costs have been around €3 million a year. So the price tag of a venture with
almost exclusively French appeal has soared to around €26 million.


You have to conclude that further
development is a long way off.


The cheapest way to break the
record again, though, would be to use the same boat. Given a few tweaks and a
great deal of luck with the weather, as many as two or three extra days could
be gained, according to experts.




But it’s a chancy game that could
take several seasons. And so we’re back to that whopping €3 million bill a year to run a boat capable of doing
almost nothing else.




It’s not a deal many sponsors
would snap up right now.




A bigger, faster, super-expensive
record hunter may be a long way off, but in a theoretical world of unlimited
money, what would such a boat look like? Could it be bigger than 130ft?




“Yes, I think we could build
a faster boat. It would be bigger and more high tech – and it would be
expensive,” says designer Vincent Lauriot Prévost
of VPLP, the design group behind Banque Populaire and two of the other round
the world recordholders, including the previous winner, the much smaller 105ft
trimaran Groupama 3.




“Longer is better in big
seas. We talked to [crewmember] Fred Le Peutrec, who sailed on both Groupama 3
and Banque Populaire, and he says they were able to push this boat much harder.
You have more reserve buoyancy in the bows and you lose less speed as you meet
each wave.




“It is critical,” Lauriot
Prévost adds, “for the main hull to be long because
you sail a lot with the main hull in the water. They are nearly always sailing
quite flat and conservatively. They don’t want to fly too high because then you
are putting too much load on the boat. Mostly the crew are sailing at 80 per
cent of the theoretical polars.” 

So length seems to be a good
parameter for consistent speed, particularly in big seas. Another equation
might be to increase righting moment by going wider. The problem with doing
that is that it costs a lot of weight and the extra power is not always
necessary.




“From what we know they
didn’t often sail with the mainsail fully up, probably 20 per cent of the time
maximum,” says Lauriot Prévost. “Width
would give more power when you don’t need it and width costs more in weight
than length.”




It would be possible to go longer
than 130ft overall, but there are factors to consider here, too. If you build
much longer you would need more than three beams (Banque Populaire has forward
and aft beams, plus a semi-circular mainsheet traveller beam). That, too, would
add extra weight and negate benefits.




“What we’d need is a target
weight and a reasonable sail plan and then we’d see what overall length would
be required to do that without having two masts and more beams.”




VPLP’s main idea would be to gain
speed by improving the foils and maybe to be able to fly two hulls more often.




“At the moment, [Banque
Populaire] doesn’t use the foils until 22 knots [boatspeed] because until then
it’s slower. There aren’t many days when they aren’t sailing at 22 knots, but
if we had bigger and more efficient foils we could reduce the speed at which
they were deployed,” suggests Lauriot Prévost.




For Lauriot Prévost’s design partner Marc Van Peteghem, another key
will be to understand the very precise weather conditions where gains can be
made and work hand-in-hand with weather experts.




“The big breakthrough is how
to go through an area of high pressure between two lows,” he says.
“If you could do that you could overtake one low and jump on to another.
The thing is to shorten the distance you sail and there are two ways: you
either go quicker through high pressure with more sail area or you go through
the low pressure with a stronger boat.”




One area that designers and crews
look at is the route around the Azores High on the way back home. Record
breakers are so fast today and weather forecasts so accurate that record
hunters can set off in tailor made conditions and be down in the South Atlantic
by the end of the first week, where they can line up to latch on to one of a
ceaseless train of low pressure systems and hitch a ride for thousands of
miles.




This is what Banque Populaire
did, riding their first Southern Ocean depression for over 3,000 miles.




However, the route back up the
Atlantic presents many less predictable obstacles, and one of the biggest is
the void of high pressure in the North Atlantic. In the worst case, sailing
round it can add 1,000 extra miles.




So if a yacht could take a
shorter route through this without losing speed, there are nearly two days to
be gained here. Designers says they need to look in more detail at how to make
a versatile boat that can blast in really heavy conditions and yet be light
enough and refined enough to glide at speed through light airs.




They need to ratchet up
sophistication and power without sacrificing too much reliability, the hardest
balance in yacht design.




Perhaps an easier record to break
would be the outright 24-hour record, which in 2009 Banque Populaire raised to
904 miles on the transatlantic record. These speeds can be attained in the
North Atlantic, where the fetch is relatively short (compared to the Southern
Ocean), the sea state comparatively flat and the runway long enough for a boat
to ride ahead of the perfect weather system.




In these conditions, a full-on
foiler like L’Hydroptere – which VPLP also designed – could theoretically go
even faster.




“It’s not possible round the
world because of the sea state in the Southern Ocean,” says Marc Van
Peteghem, “but in the Atlantic I believe we could soon do 1,000 miles in
24 hours.”





Photos:

Aerial shots: Carlo Borlenghi

Onboard shots: Digby Fox