Seamless – Part I - Hall Spars and Rigging

Seamless
– Part I
Eric Hall gives a potted
history of the one-piece
carbon mast tube
Since its founding in 1980 Hall have always
pursued a ‘best way’ approach to their
products and processes. In the custom spar
business the best way is a combination of
sound, creative engineering, latest process
technology, modern facilities, a focused and
skilled workforce allied to the latest
computer-controlled machinery. Hall Spars
have been in the composite spar business
since 1984, longer than any existing sparmaker we know of today. Our composite
spar technology began with wet layup,
vinylester carbon composite spinnaker poles
and booms. Our first pole was built in 1984
for the Maxi Boomerang, followed by a pole
for the J-Class Endeavour, fresh from her
original, first Huisman refit.
In 1989 we retooled our original small,
sticky and dusty wet layup room to a clean
room with oven to cure vacuum-bagged
pre-preg carbon composites. Highlight
jobs with these new facilities and processes
were spinnaker poles and booms for the
new America’s Cup Class as well as some
airfoil-section catamaran masts as well as
34 SEAHORSE
the bi-pole rig for Harken’s groundbreaking, canting-keel 50-footer Procyon. Then
in 1991 we installed our first (19m) autoclave. Today Hall factories in the US, Holland and New Zealand each have superyacht autoclave capacity in excess of 43m.
Designing and building rigs for today’s
modern sailing yachts is an interesting and
complex activity. Doing it the best way
begins with understanding and applying the
basics of advanced composite structures.
Process technology – pre-preg
carbon fibre
With composite structures it’s basic: the
straighter the fibre the higher the strength
and stiffness (and optimum weight)
properties of the laminate. Using wet layup techniques, fibre straightness is difficult
to achieve. On the other hand, fibre
straightness is significantly improved using
pre-preg materials.
Unidirectional pre-preg carbon is
supplied on backing paper with the fibres
in precise parallel alignment, impregnated
with heat cure epoxy that is basically dry
to the touch at room temperature. Layups
in unidirectional carbon have maximum
fibre straightness, thus maximum stiffness
and strength.
Another advantage of pre-preg over wet
layup is its absolute weight predictability.
The heat cure epoxy is impregnated into
the carbon using extremely precise
processes, ensuring that pre-preg materials
have predictable and repeatable resin contents. This means that both strength and
weight calculations will be accurate. All
pre-preg suppliers qualify and quantify the
resin content properties of each shipment,
usually within 1 or 2%.
Pre-preg carbon, as noted, is dry to the
touch at room temperature. During cure
the resin first becomes liquid at a middle
temperature (800C) stage, is held there for
a while, then is elevated to a final curing
temperature, in our case of 1200C.
Pre-pregs come in various weights and
properties. The most frequently discussed
property of carbon is modulus of elasticity.
There are four basic modulus choices:
standard, intermediate, high and superhigh modulus. Standard modulus is the
everyday choice that has reasonable modulus, very good strength and lowest price.
At the other end of the spectrum (not
counting ultra exotic versions not really
suitable for rigs) is super-high modulus
(for example, HS 40). This has a very high
modulus of elasticity and a very high price,
but it is a relatively brittle pre-preg material requiring great care during manufacturing. However, properly executed, a mast in
super-high modulus carbon offers significant advantages in weight and stiffness.
Autoclave curing
My own career started at Grumman
Aircraft, and from there I already knew
that our original vacuum bag processing
of oven-cured pre-preg laminates was
ultimately not a ‘best way’ process. The
best way to process pre-preg laminates was
in an aerospace-grade autoclave.
Autoclave curing applies high pressure
(in our case 6 bar) to the laminate for much
GILLES MARTIN-RAGET
SH July Hall hoi res_S_H May Rob.qxd 21/05/2013 12:07 Page 2
Forty years ago Eric Hall cut his own teeth
building some experimental lightweight
composite spinnaker poles for 12 Metres
but it was the ACC class that put the spar
company that now bears his name on the
America’s Cup map, first with America3 in
1992 (left) and later with the Alinghi team.
A pretty successful bunch of customers…
masts using this process and have been
rewarded with a long list of race winners
and record-setters while maintaining an
enviable reliability record.
the same reason clamps are used to laminate wood structures. The process stems
from the early aircraft industry where
many components were made of wood.
The British aircraft company De Havilland
pioneered autoclave-cured moulded plywood and used it extensively in their
famous World War II Mosquito bomber –
as well as in their Vampire jet aircraft that
entered service just after the end of the war.
Why autoclave pressure? Because it practically eliminates voids (to well below 1%
void content). By comparison, vacuum bagging the same pre-preg carbon laminates
will leave voids of 3-4%. Voids rob laminates of static and fatigue strength in much
the same way as do cavities in low-tech
metal castings. In composites the difference
in strength can be significant. If vacuum
bagging must be used more material and
thus weight must be added to compensate.
Autoclave curing also further straightens
and aligns fibres (remember fibre straightness…) to maximise strength and stiffness.
In 1991 Hall acquired their first (19m)
autoclave to bring their products up to
advanced aerospace composite levels. At
the same time Bill Koch’s highly scientific
America’s Cup team America3, hearing of
our plans, committed to exclusive America’s Cup usage of our ’clave through the
end of the 1992 Cup. From late 1991 until
the end of the Cup the following year the
Hall autoclave was in operation seven days
a week, including quite a few 18 and 24
hour days. In less than a year we acquired
valuable experience that would have taken
five years under more normal conditions
of making less ambitious products.
It was during this period that the
America3 engineering brain trust, after an
intensive study, concluded that of all
known methods of making tubes, making
them seamlessly over male mandrels was
in their opinion technically the best way.
Partly as a consequence of this evaluation,
we then moved rapidly to perfect seamless
tube moulding as our method of choice.
Since then Hall have built thousands of
AUSTRALIA
Modern purpose-built facilities
The Hall ‘best way’ approach extends to
facilities. The company has always put a
premium on state-of-the-art, purpose-built
factories. After only eight years in business
we moved into a new factory designed and
built for sparmaking in 1988. Then in 2001
Hall acquired Proctor Spars in Holland and
within six months moved into a brand new
building in that country similarly designed
specifically for sparmaking. In 2004 Hall
USA, having outgrown their 1988 facility,
once again designed, built and moved into
another brand new, much larger factory.
Three years later Hall added a major new
building to their Holland facilities, this time
specifically designed for superyacht spars.
With facilities made specifically for
sparmaking it is easy to understand that all
aspects of the job – from engineering to
parking lot loading logistics – can be
executed that much more smoothly.
BRISBANE +61.7.3348.7245 andrew@ullmansails.com.au
PERTH +61.418.612.262 brad@ullmansails.com.au
SYDNEY +61.2.9529.8546 bruce@ullmansails.com.au
WHITSUNDAY +61.7.4948.3016 whitsunday@ullmansails.com.au
Process skills
Advanced composite construction in any
industry, from aerospace to Formula One,
requires a high level of skill, focus and
training. Since sparmaking remains mainly
a prototype, ‘one-off’ activity, employing
repetitive machinery is difficult. For
instance, a machine might be able to be
pre-programmed to cut holes in a mast,
but few machines can duplicate the
detailed finishing work required, for
instance, to smooth those corners where a
rope may still chafe.
There is also of course machinery to
automatically lay tapes down on mandrels.
But the suppliers of such machinery still run
into challenges when laying down tapes
over a compound tapering surface such as
in the masthead area. Ultimately, anything
is possible with machinery, but aerospace
capital budgets are required, budgets that
the yacht market cannot possibly support.
Nor is the lone, skilled craftsman the
answer. In a good process the parts must be
designed so that every member of a wellrehearsed construction team can perform
identically well during mast manufacture.
DRAMMEN +47.32.818.495 peter@ullmansails.no
Computer-controlled machinery
Make no mistake: along with the need for
highly skilled hand crafting, computerdriven machinery is a must in modern
custom sparmaking. At Hall we combine
in-house with outside vendor CNC
machinery for our operational needs.
In house, a single highly versatile machine
cuts not only the uncured pre-preg for 䊳
CROATIA
RIJEKA +385.51.288.661 grego@ullmansails.hr
DENMARK
AARHUS +45.29.42.05.79 info@ullmansails-denmark.dk
FINLAND
HELSINKI +7.921.797.30.11 ullmansails@mail.ru
FRANCE
LORIENT +33.0.297.350.723 ceb@ullmansails-atlantique.fr
ITALY
PARATICO +39.035.917.847 info@ullmangz.it
TRIESTE +39.040.832.3434 ullmansails@ullmansails.it
JAPAN
KANAGAWA +81.46.882.2791 info@ullmansails-japan.com
MEXICO
ACAPULCO +52.7.444.83.8432 tomas@beneteaumex.com
MONTENEGRO
TIVAT +382.67.373067 grego@ullmansails.hr
NORWAY
RUSSIA
ST. PETERSBURG +7.921.797.30.11 ullmansails@mail.ru
TAGANROG +7.8634.64.35.68 ullmanrus@gmail.com
SWEDEN
SKARHAMN +46.0.730.608.493 info@ullmansails.se
SWITZERLAND
ROMANSHORN +41.71.793.1249 info@ullmansails.ch
TURKEY
ISTANBUL +90.216.391.9752 yeliz@ullmansails-turkiye.com
IZMIR +90.232.257.6341 info@ullmansails-turkiye.com
KUSADASI +90.256.618.2814 basar@ullmansails-turkiye.com
UNITED KINGDOM
PLYMOUTH +44.0.1752.550040 chris@ullmansails.co.uk
HAMBLE +44.0.2380.456611 sales@ullmansails.co.uk
UNITED STATES OF AMERICA
CHESAPEAKE
EASTON +1.410.310.7992 msimington@ullmansails.com
DELTAVILLE +1.804.776.6151 jerry@ullmansails.com
GREAT LAKES
BUFFALO +1.716.447.9766 ullmanbuffalo@aol.com
CLEVELAND +1.216.486.5732 ullmancleveland@aol.com
SOUTH
NEW ORLEANS +1.985.626.5638 gulfcoast@ullmansails.com
SARASOTA +1.941.951.0189 ullmansails@ullfl.net
WEST COAST
HONOLULU +1.808.593.9958 ullmanhi@artnelsonsailmaker.com
SAN DIEGO +1.619.226.1133 sailsinfo@ullmansailssandiego.com
SANTA ANA +1.714.432.1860 ullman@ullmansails.com
SEATTLE +1.206.234.3737 sailsinfo@ullmansailsseattle.com
VENTURA +1.805.644.9579 ullmanventura1@att.net
SEAHORSE 35
SH July Hall hoi res_S_H May Rob.qxd 21/05/2013 12:08 Page 4
Above: to build superyacht spars, first build a big factory… this is Hall Spars’ 60m paint booth in the Netherlands. Two identical
booths operate in parallel, one for primer one for top coat. Laminate debulking (top right) must be done at each stage and done well.
Hall operate identical 46m autoclaves in the Netherlands (right) and the USA and a slightly smaller one at their New Zealand facility
detailed reinforcement patches around mast
hard points like spreaders, tangs, mastheads
and so on but also machines hard materials
such as cured carbon, MDF tooling material
and aluminium… all in three axes. Hall also
have larger CNC machining centres for
aluminium and stainless parts, usually for
OEM projects and for making metal moulds.
Finally, a computer-controlled turning centre
was recently added to relieve growing
pressure on sheave and bush manufacture.
Where high precision in stainless and
titanium parts is required Hall use external
vendors with their own sophisticated
machinery. The tight-tolerance titanium
fittings for our SCR carbon rigging product line, for instance, are all manufactured
at a local company, aerospace-certified
and equipped with a number of multi-axis
high-precision machines.
Seamless masts explained
As noted above, Hall have now been
making seamless moulded masts for over
20 years. So what exactly is seamless
moulding? On the face of it a simple
concept: wrap pre-preg carbon material
around a tube, put it in a vacuum bag and
(as in our case) cure it under high temperature and pressure in an autoclave.
Drill down and it’s a bit more
complex
As with things that look easy in sport or
music, successful seamless moulding
requires years of focused practice and experience. Each layer is applied to the mandrel
only when it perfectly butts to the layer next
to it. No overlaps are acceptable (again,
fibre straightness!). This is especially a
challenge with off-axis layers where
painstaking trimming is required to make
the butts perfect. Yet watching experienced
hands do this work, one can easily conclude
that it’s a simple job. It is – if, like an accomplished pianist who makes playing look
easy, you’ve done it for a long while. And as
with sport and music, the job continually
seduces one to work at ever higher levels.
36 SEAHORSE
Fibre straightness also requires debulking at practically every layer. Debulking is
accomplished by wrapping the laminate/
mould with clear plastic stretch tape in
tension to compact the latest layer, then
removing it once the full laminate length
has been wrapped. It’s very time consuming but very necessary: without debulking
the laminate would not be tightly attached
to the mandrel and could wrinkle under
autoclave pressure, compromising final
performance.
Another feature of seamless moulding is
that the difference in thermal expansion of
the mould material vs carbon acts to
increase fibre straightness. As oven heat
increases, mandrels increase slightly in
length and diameter, stretching and
straightening fibres in addition to the
straightening already accomplished with
debulking. Upon cooling, the mandrels then
contract more than the cured carbon part,
easing extraction. Among the advantages
we see in seamless moulding are:
䢇 Structural simplicity
䢇 No joints, glue or fasteners
䢇 Maximum strength/stiffness-to-weight
䢇 Windage
䢇 Tooled inner surface
Simplicity
The seamless mast is structurally very
simple: it comes off the mandrel finished in
one homogeneous piece. In contrast, a
female moulded tube must first be laminated in two or more shells, and then
joined with glue and fasteners (to prevent
seam-glue failure).
One of the properties of a seamless mast
is that the off-axis fibres are continuous.
Where 45 or 90° fibres appear, for
instance, each is secure and unbroken
throughout its length. In a female moulded
tube each off-axis layer is interrupted at
the side join so no such layer spans more
than half a mast circumference. This seamless tube ‘circumferential continuity’
ensures maximum structural integrity by
minimising structural complexity.
Strength and windage
Again structural simplicity has its reward
in lower weight. No lap joint, excess glue,
fasteners or side join fairing compound.
For the same stiffness we believe that the
seamless mast tube, unencumbered by the
weight of two side joins, should always be
lighter. If one has to meet minimum
weight constraints the tube can be smaller
for equal weight and stiffness. If the section is smaller, windage gains will be
made. Since the mast is a major source of
windage drag, gains here are meaningful.
Tooled inner surface
The seamless mast is made on a male
mandrel so the inside surface is the tooled
surface (a well-made seamless mast will
also have very smooth external surfaces).
Because the inner surface is tooled, fittings
attached within the mast (as most are
today, for windage reduction) can be a
precision fit with no re-machining.
Hall have come a long way in seamless
mast making, gradually improving tube
quality through training, practice and
process improvement. We will be the first
to admit (today, maybe not then!) that our
early outer surface finish needed improving, especially in unfaired, clear-coated
masts. Today quality has improved to the
point that even our clear-coated masts give
the impression of a tooled outer surface.
Engineering
Once, in the days of aluminum masts,
engineering was a relatively simple matter:
determine the general size required, pick
the nearest suitable section then attach the
standard fittings designed for that tube
size. When carbon composite masts
arrived on the scene things became a lot
more interesting and from a design standpoint a lot more complex.
Once the designer has given us the basic
parameters our engineers enter the data in
our Rig Calculation Program (‘RC Sheet’
for short). Once the designer data is
entered the RC Sheet creates 20-plus pages
Far left: purpose-built – Hall Holland’s
carbon shop mirrors their US counterpart.
Below left: continuous off-axis laminating
on a seamless tube. Note autoclave size in
the background. A finished (left) seamless
tube with its characteristic smooth, tooled
inside surface plus elegant clear exterior
of output of all kinds. One of these pages is
the laminate sheet, with laminates determined layer by layer to optimise mast
properties including safety factors. Once
the tube is designed its properties are then
checked and further optimised in a Finite
Element Analysis (FEA) program.
Although the RC Sheet includes rigging
sizes these also are optimised at the FEA
stage. Critical bend characteristics are
determined at this stage and, when
finalised, are submitted to the sailmaker
for the mainsail design. FEA is a great tool
for creating very accurate mast tuning and
bend properties. A sailmaker can rely on
the precise outputs FEA gives.
One thing to say about FEA: as with
everything else, continuous practice pays
dividends. Gunnar Salkind, Hall’s Boeingtrained chief designer, has over 20 years’
experience perfecting his FEA capabilities.
His rigs are impressively light yet always
easily controlled and tuned. FEA can also
be credited for changing the game of dock
tune, where masts tuned to FEA mast step
pressure outputs now require practically
no further tuning under sail other than
obvious changes to suit racing conditions.
Racing spars
It’s a fascinating task, making racing masts
that push the creative limits of strength,
stiffness, weight, windage and function.
This of course requires the support and
commitment of the client, as we are talking
not only many more engineering hours but
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asked to build an all-out race spar we work
very closely with the team getting their
input and defining their goals for the rig,
then design accordingly. Every single detail
on the mast from the masthead wand connection to the hydraulic mast step will be a
brand new design.
This enterprise has, of course, attendant
risks. If you are basically experimenting
with every detail – especially on a racing
boat – the risks increase. So the art of the
process is to know how to design new
creative details that will still survive the
ambitions of a racing crew. The art
includes understanding that these demands
and ambitions push the envelope ever
harder. And as materials get stronger and
stiffer, this means anticipating everincreasing dynamic loadings under sail.
To succeed, we have to have good
laminates, good designs, well-made parts
and, just as important, assembly skills that
require extraordinary focus. As with the
laminating process, this only comes with
training and experience. As with athletes
and musicians, virtuoso performance is
only attained after years of practice.
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SEAHORSE 37
SH Aug Hall THIS final_S_H May Rob.qxd 20/06/2013 07:25 Page 1
All-conquering – Bella Mente making good use of her second, super-clean Hall Spars rig while winning this year’s Palma Vela
Case study: Hall Spars
engineer Gunnar Salkind
and rig project manager
Alex Wadson discuss the
design and manufacturing
evolution of the latest race
spar for the Judel-Vrolijk
Mini Maxi Bella Mente
With a win in the 2012 Maxi Rolex Cup,
followed by winning the 2013 Palma Vela
regatta, Bella Mente has very much become
the boat to beat in the Mediterranean. The
Bella Mente programme has always been
relentlessly focused on continuous improvement from design to racecourse and their
latest campaign is no different. Hall Spars
have been a member of the team since
before the present boat was built and our
efforts have been reflective of the team’s
active approach to everything they do.
Since Hall became involved with Bella
Mente they have built three rigs for the
programme. The first was made for the
Rig 2, though, we were convinced Gunnar
needed no help… He’s a very impressive
operator.’
[Editor’s note: A few months before the
delivery of the 2012 rig Gunnar Salkind
suffered a serious motorcycle accident and
only a superior level of fitness from cycling
saved his life. During the early days of a
long and difficult recovery, the Bella Mente
team showed their respect and affection for
Gunnar by giving him an iPad to help
distract and entertain him during the frustratingly long physical recovery. ‘As with
everyone around him, we were extremely
concerned. And we’re delighted he came
back in time for Rig 2!’ adds Wadson.]
Wadson continues… ‘Hap Fauth told us
he wanted the most weight-optimised rig
possible without compromising strength.
While we knew that the seamless Hall
section for Rig 1 was very close to optimal,
we nevertheless asked Gunnar if he could
safely get any more weight out of the tube.
‘We had always felt that the team’s
requirement to analyse the tube for
righting moment at 23° was slightly conservative,’ said Gunnar Salkind. ‘We were
sure that going to RM20 in a quest to
shave some laminate weight would still
create a reliable tube – so we set about
selling the idea to the team. That was the
start of a pretty serious weight diet.
‘Based on RM20, we revisited the mast
with our RC Sheet [Hall’s proprietary rig
calculation program] and refined the laminate page. Then we once again studied and
refined the mast in FEA to confirm our 䊳
JESUS RENEDO
Seamless
– Part II
original Bella Mente on very short notice
for the Transpac Race in 2011. Lead time
was very tight but Hall delivered a new
mast in time for the race… Just!
The team were happy with the rig – and
with the fast delivery – and asked Hall to
design and build the rig for a new Bella
Mente designed by Judel-Vrolijk and at the
time under construction at New England
Boatworks. The first rig Hall built for the
new boat was an inshore spar with tube
design by Scott Ferguson. This mast was
fitted with a Harken track and luff cars
and provision for two reef points. The rig
performed well and a second one was soon
being considered. The first brief was aimed
at a beefed-up rig suitable for the SydneyHobart race. Ultimately the team changed
strategy and after winning the 2012 Maxi
Rolex Cup they went in the other direction
and switched the brief to a very weightoptimised inshore design.
The Bella Mente team requested that
the 2012 rig (Rig 1) design be a collaboration between Scott Ferguson and Hall’s
chief engineer Gunnar Salkind. Rig 2 was
an all-Hall project led by Salkind with
Alex Wadson closely involved as rig coordinator. ‘When we went to make the rig
for the new Bella Mente being built at
New England Boatworks we really hadn’t
worked much with Gunnar other than on
the Transpac rig for the old boat, which
was on such a tight schedule that refining
design details took a back seat,’ said
Wadson. ‘So we asked Scott to look over
his shoulder. When it was time to design
SEAHORSE 39
SH Aug Hall THIS final_S_H May Rob.qxd 20/06/2013 07:25 Page 2
new laminate. One of the best things we
did on Rig 1 was install a comprehensive
load-sensing system. That allowed us to
check our calculations using real-life loads.
It was a great source of personal satisfaction to me that those recorded loads
matched the FEA results very closely.’
Hall also worked very closely with
North Sails designer Chris Williams and
parallel studies were undertaken using
North’s own Membrane program. ‘There
was almost 100 per cent agreement
between Gunnar’s and North’s results,’
said Wadson. ‘Where there was one small
difference we evaluated it further and went
with Gunnar’s solution. Otherwise, the
collaboration between North and Hall
worked flawlessly.’
Once the tube laminate was defined the
Hall-Bella Mente team of Gunnar Salkind,
Alex Wadson and Peter Henderson looked
hard at every fitting on the mast for further
weight savings. ‘The first two obvious
places were the mainsail track and reefing
systems,’ said Wadson. ‘On Rig 1 we had
an aluminium headboard car track.
Replacing it with a carbon boltrope track
was an obvious choice for weight saving.
Also, since the mast brief was now aimed
solely at inshore racing we decided to eliminate any provision for reefing, adding
further to what we could save.’ Meanwhile, the team itself also wanted to trial
40 SEAHORSE
a lighter new deflector system which
ultimately proved successful.
After refining the laminate and studying
and refining every fitting Hall ended up
saving a significant amount of weight over
Rig 1, with no compromise in strength. ‘It
took a long time and a lot of design spirals
for everyone to feel comfortable,’ said
Salkind. ‘But even we were surprised by
the scale of the global saving we achieved.’
Actually, each rig Hall built for Bella
Mente provided an interesting comparison
in how a mast builder interacts with a sailing team when multiple rigs are built. ‘On
the Transpac rig the team just wanted to get
the mast done and make sure it was in the
boat in the short lead time we had. Any
information we needed from them we got
instantly from Peter Henderson and Rob
Oullette and decisions were made quickly.
‘On Rig 1 for the new boat the lead time
was more controlled and the team met us
almost daily to go over details. The communication was just about immediate but we
had the luxury of spending maximum time
on details,’ said Salkind. ‘Designing and
building Rig 2 was a different atmosphere
again: the team were now away most of the
time with the boat at different regattas.
Ideas, information and decisions naturally
moved less quickly. Each rig project had its
own flavour and its own challenges.’
‘One of the things we wanted for the
new rig was a more compact masthead,’
said Wadson. ‘On the first mast the masthead was well above the P band. Taking a
page out of the TP52 book, we asked
Gunnar to design a compact craneless
aluminium mast cap with sheaves only for
the spinnakers.’
‘The new mast was barely high enough
to allow for the P measurement and was
otherwise just as lean as we could possibly
design it,’ said Salkind.
The same philosophy was applied in
every area. ‘One decision we made on Rig 2
was to change over to Carbo-Link solid
carbon semi-continuous rigging to reduce
windage compared with the previous
continuous EC6 on Rig 1,’ said Wadson.
‘We also considered Hall’s continuous
SCR Airfoil rigging, but when the rigging
decision was made in mid-summer Hall had
not yet delivered the first sets and understandably Hap wanted to see it being used
out in the field first!’ adds Watson.
Halyard locks are another area of
constant development. ‘We felt we could
save weight and make the mast perform
better,’ said Salkind, describing Bella
Mente’s latest headstay locks. ‘So we
replaced the Rig 1 system and, working
closely with the rigging supplier, came up
with a hollow titanium through-tube plus
lashing bollards to eliminate headstay
lock-induced bending.
‘On Rig 1 we also had a crossbar-type
upper shroud tang to accommodate the
EC6 internal fittings,’ said Salkind. ‘On the
new rig the more compact solid carbon
rigging fittings allowed us to optimise the
upper tang and save a few more grammes.’
The spreader system was virtually the
same as before but with smaller tangs
required for the solid carbon shrouds. The
smaller solid carbon D shroud terminals
allowed significantly smaller mast cutouts.
The spreader tips were also changed for
the new solid carbon rigging.
‘Although we kept locks on the headsails
and main we eliminated the genoa staysail
lock to save a bit of weight,’ said Wadson.
‘A small side bonus due to no reefing was
the partner design that was a bit more
waterproof without the through-deck fairleads. We made no changes to the halyards
– these are all led below deck as on Rig 1.
‘One cannot achieve results with design
and team advice alone. It takes special
spar-building skills to keep up with
demanding sailors,’ said Wadson. ‘Hall’s
team once again delivered us a great mast.
Still one person stands out: sparmaker
Jason Charbonneau built the mast and
when it came to delivering a sophisticated,
beautifully finished product he was more
than up to the task. His skills with carbon
finishing are impressive.’
The overall goal of weight saving with
reliability was satisfactorily met, according
to Wadson. ‘We pushed Gunnar and his
team hard to come up with improvements
on the whole rig,’ he said. ‘The result looks
very good indeed. When we first started
talking about the mast our weight-saving
calculations frankly sounded a bit optimistic. But the team pushed us and that
such a seemingly distant goal was achieved
was greatly satisfying to us all.’
Bella Mente’s two-boom programme
went through a similar evolution. The
basic construction of the booms is carbonNomex honeycomb sandwich. One boom
was designed for offshore service and
included two reefs and higher safety
factors. Both booms feature strop ‘fuses’
that are designed to break if peak design
loads are exceeded; this way the booms
could be designed to an exact load without
worrying about exceeding the load and
breaking the boom in an unexpected load
event. Hall built both the current inshore
and offshore booms alongside Rig 1.
‘We designed the inshore boom with
virtually only a gooseneck, a vang fitting
and an outhaul,’ said Salkind. ‘All the core
cutout/solid carbon hardpoint sizes were
reduced to the minimum possible. The
inshore boom was also designed with a
lower load fuse, allowing slightly less
structure. The combination of all the
refinements allowed us to reduce this
boom’s weight by more than 20 per cent.’
The new inshore mast was shipped with
the boat from Florida to Palma in April
and commissioned just before Palma Vela.
Alex Wadson assisted Hall project manager David Moffet in rigging it. ‘We were
on a tight schedule because the ship only
made it just in time,’ said Wadson. ‘I am
glad David was in charge; if there is anyone who can make something happen he
can. And once the rig was in the boat there
is no one better at tuning.
‘Then it was up to us [the team],’ said
Wadson. ‘Gunnar, David and the Hall
guys did a great job. Without their efforts
winning (let alone even participating in)
this year’s Palma Vela would have been
very difficult indeed.
‘The tireless Bella Mente team also
made it happen. We were sailing competitively against the other boats exactly one
week after the ship tied up in Palma ’ Fusion M:
™
Fast,
efficient,
durable,
and
infinitely
repeatable.
QUANTUM SAIL DESIGN GROUP
MMM
Far left: vang, mast gate and gooseneck
detailing seen onboard the latest Bella
Mente give a good idea of the intense
windage and weight-reduction programme
that was applied to this obviously inshore
targeted rig project. There is absolutely
nothing redundant on Bella Mente’s spars
in terms of components, nor unnecessary
metalwork – note the carbon fibre tripline
guide to starboard where the mast goes
through the deck. The minimalist carbon
rigging is by Swiss company Carbo-Link,
who enhanced their already impressive
reputation with the successful platform
rigging of the Deed of Gift cat Alinghi 5.
Carbo-Link are also active in industrial,
Formula One and aerospace composites.
Top left: jib-lock with Carbo-Link system
to eliminate moment load on the headstay
.QUANTUMSAILS.COM
Photography: Tim Wilkes
SEAHORSE 41