World's Largest
Trimaran
by Hélène Leplomb
With a wealth of experience acquired through
the construction of a long line of racing boats,
the Banque Populaire has gained considerable
notoriety in the field of sailing. The “Sailing
Bank” is staying its course with a new challenge:
the construction of the world’s largest trimaran
– the Banque Populaire V. Designed with the
aim of beating the major sailing records, it consists of a forty-meter-long central hull, floats
measuring thirty-seven meters in length and a
forty-five-meter mast. The “Sailing Bank” has
chosen the French company Ecartip to measure
and test the manufactured parts using a Leica
Geosystems 3D laser scanner.
Technological choices are essential in the race for
performance. Consequently, for the structure of
the Banque Populaire V, the technical team relied
on tried-and-tested technology: a layer of Nomex
(strong synthetic fibres in honeycomb structure)
between two layers of carbon. There was a risk that
the components of this immense prototype would
warp during this process due to the heat. That is why
Olivier Bordeau, a member of Team Banque Populaire
and responsible for monitoring compounds, called
on Ecartip, a company originally consisting of land
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surveyors, but now also working in the shipbuilding industry, to measure and test the boat’s components using a 3D laser scanner. The aim was to test
the deviation between the manufactured parts and
the theoretical digital model in order to identify any
distortion and to take appropriate action to ensure
that the performance of the boat complied with the
initial plan.
Scan of the hull and floats
Two employees at Ecartip were called upon to scan
the different components and process the data onsite in order to save time. During these operations,
Eric Rabaud, project leader at Ecartip, appreciated
the full dome of the Leica HDS3000 laser scanner:
“The full dome meant that the bottoms of the hulls
could be scanned quickly and with no restrictions
by placing the scanner on the ground. Without this
characteristic, we would have had to raise the floats
and that would have been impossible!”
The thirty-seven-meter-long floats required 10 scan
positions each. These multiple scans enabled Ecartip
to obtain a level of precision of ± 4 mm in assembling a scatter plot and ± 2 mm in modelling. Ecartip
could therefore provide sections, 3D views, reports
presenting the deviations obtained and verification
plans in order to check the conformity of the boat’s
components. By modelling the hulls, they were able
to define the real axes and planes of symmetry of the
boat. The different parts of the boat could therefore
be repositioned precisely taking into account the distortions observed and the mechanical characteristics
of the boat. This precision operation was decisive in
positioning the centreboard well, foils, rudder blade
and other parts of the boat.
Finding himself five days ahead of schedule, the
leader of Team Banque Populaire was entirely convinced: “Before, we didn’t know why the boat was
pulling more to the right or to the left – we used a
plumb line and a decameter to check the manufactured parts. This technology allows us to save time,
increase the reliability and precision of the measurements and, above all, correct the axis of symmetry
before the launch!” exclaimed Olivier Bordeau.
Providing help in assembly
Assembling this type of component is not easy and
precise positioning is essential. In the past, the components were guided into position on the central hull
using a projection on the ground, a plumb line and a
spirit level. This meticulous work could take days to
be completed. Then the part in question would be
cut and positioned and these operations would be
repeated until it was perfectly fitted.
Already won over by the service provided by Ecartip,
Team Banque Populaire decided to test the assembly
of the arms on the central hull using a Leica HDS3000.
Eric Rabaud identified the zone to be cut on model
elements of the boat before marking the outline on
the hull using a theodolite. “We are used to working with a safety margin”, explains Olivier Bordeau.
“Initially we didn’t want to take the risk of cutting
exactly along the outline…” However, from the very
first cut, the team had to accept the obvious: the
outline was perfect. As a result, the scanner monitored the entire progression of the boat’s assembly,
providing invaluable aid in assembling the hulls and
positioning the foils.
This first 3D laser scan service has revolutionised
measurement techniques in the field of racing boats:
“In the past, there was no real culture of measurement in this domain, it is a revolution in our measurement system”, confirms Olivier Bordeau. The test and
assembly operations took only a third of the time
allowed for in the very tight construction schedule
for this prototype, enabling the installation of the
elements on the central hull to be adapted to ensure
optimum geometry of the boat.
The availability and commitment of Ecartip were
greatly appreciated by Team Banque Populaire, who
will be sure to contact Ecartip when they make future
modifications to the boats in the fleet of the “Sailing
Bank”. For his part, Eric Rabaud from Ecartip could
feel the team spirit which reigned around the boat,
giving him the feeling that he too was part of this
great adventure.
About the author:
Hélène Leplomb is responsible for Marketing at Leica
Geosystems in France.
Banque Populaire V
Type: Crewed Oceanic Maxi Trimaran
Skipper: Pascal Bidégorry
Length: 40.00 m
Breadth: 23.00 m
Displacement: 23 t
Draught: 5.80 m
Clearance: 45 m
www.voile.banquepopulaire.fr
www.ecartip.fr
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