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DIAB ‘SOLUTIONS’ - SPRING 2007 - 2
The New Low FST Core Material from DIAB
Commercial aircraft interiors are a major application area for Divinycell F.
Train interiors is another major market for Divinycell F.
DIAB’s new manufacturing facility for Divinycell F is adjacent to the company’s existing plant in DeSoto, Texas.
E FNE
WS
Divinycell F is a signifi-
cant breakthrough in core
material development,
offering low FST (fire, smoke and
toxicity) properties coupled with
good mechanical and processing
characteristics.
Developed by DIAB primarily
for the commercial aircraft and
public transportation markets, it
more than exceeds the USA and
European regulatory requirements
for aircraft interiors and the Euro-
pean train FST requirements.
Other key features include
superior damage tolerance, ex-
ceptional fatigue life, low water
absorption and excellent heat
ageing at 180°C (356°F). Chemical
resistance to the majority of aircraft
fluids is also excellent.
Divinycell F is compatible with
most common composite manu-
facturing processes up to 220°C
(428°F) cure cycles, including
infusion. When used with most
pre-pregs it does not require the
use of a film adhesive. It is also
compatible with most common
thermoplastic and thermoset resins
including the epoxies and modern
phenolics used by both aircraft and
train manufacturers.
With its superior fire properties
Divinycell F is ideal for aircraft
interiors including wall panelling,
ceiling modules, luggage bins and
doors/lockers. Its close cell struc-
ture makes it particularly suitable
for galleys and toilets.
It is also an excellent sandwich
core material for train and subway
interiors, exceeding as it does,
the new EN 45545-2 regulatory
requirements.
The new material will be manu-
factured in a dedicated production
facility that is close to DIAB’s ex-
isting DeSoto, Texas, operation.
Initially, Divinycell F will be avail-
able in three densities - 50, 90 and
130 kg/m3 (3.1, 5.6 and 8.1 lb/ft3)
and can be supplied in both plain
sheets and kit form.
High temperature resistance. (+220°C/-195°C).
● Excellent fire behavior. (Very low smoke & toxicity)
● Low water absorption.
● Excellent fatigue life.
● Superior damage tolerance.
● More processing friendly.
● No film adhesive required.
DIAB ‘SOLUTIONS’ - SPRING 2007 - 3
LOW DENSITY ADDITION TO DIVINYCELL HP RANGE
Thailand Facility EstablishedDIAB has enhanced its support
for the South-East Asian market by
establishing a new facility in Chon-
buri near Bangkok in Thailand. As a
result of setting up the new facility,
DIAB will be able to offer an even
faster response to customer needs
in Thailand, Malaysia, Singapore,
Vietnam, the Philippines, Laos and
Indonesia.
The new facility will not just be
a sales operation but will include
technical service personnel who will
be able to assist DIAB customers in
the region with the introduction of
new processing techniques such
as Core Infusion Technology™ and
‘ready to use’ core kits – both of
which have been pioneered around
the world by DIAB.
In addition, the new facility will
carry out finishing operations to
more closely meet the particular
core material requirements of the
region and specific DIAB custom-
ers.
Commenting on the new facility,
Johan Gralén, VP Sales & Market-
ing AAO, said “The investment in
the new Thailand operation follows
on closely from the establishment
last year of our Chinese facility
and the recent announcement of
the addition of a kit manufacturing
production unit in Shanghai. It is
a clear demonstration of DIAB’s
long term commitment to the Asian
market.”
DIAB’s new Thailand facility in Chonburi near Bangkok.
DIAB has expanded its Divinycell
HP range of core materials with the
addition of a low density version -
HP60. It offers all the advantages
of the existing HP range - excellent
mechanicals, high processing and
service life temperatures - yet with
its nominal density of just 65 kg/m3
(4.1 lb/ft3), it will allow further weight
reductions in advanced sandwich
composite structures.
The main application areas
for the new material will be the
wind energy and marine markets,
especially those companies using
prepregs.
The high compressive strength
and modulus of HP60 allows it to
resist the buckling loads expe-
rienced in wind blades whereas
its high service life temperature
makes it ideal for dark colored
decks and superstructures.
With its elevated process-
ing temperature of up to 140°C
(284°F), outstanding adhesion and
peel strength, Divinycell HP60 is
fully compatible with the majority
of epoxy prepregs. It can also be
readily used for closed molding
processes such as resin infusion
and RTM (resin transfer molding)
where high exothermic tempera-
tures can be encountered.
As with the other densities in
the range, Divinycell HP60 has
good shear strength and modulus
values. Similarly its shear strain fig-
ure clearly demonstrates its good
ductility and energy absorption
characteristics. HP60 also offers
good chemical resistance, excel-
lent insulation properties and is
self-extinguishing.
Wind energy will be one of the main application areas for Divinycell HP60.
DIAB ‘SOLUTIONS’ - SPRING 2007 - 4
MAR
INE DYNA CRAFT & DIAB
When leading Taiwanese
boat builder, Dyna Craft,
contemplated introduc-
ing closed molding technology
in order to increase production
without reducing quality, it naturally
looked at vacuum infusion mold-
ing. Other yards in Taiwan had
already gone down this route but
Dyna Craft was concerned that
with some of the methods on offer
the set-up was complex, a high
amount of consumables were used
and surface finish was often poor.
The company then evaluated
DIAB Core Infusion Technology™
and found that the set-up was
simple and consumable costs were
very low. As a result DIAB Techni-
cal Services in China was asked to
put together a complete program
to introduce the new technology.
The program began with an on-site,
five day, comprehensive training
course attended by Dyna Craft
production, engineering and man-
agement personnel that included
exhaustive training manuals in both
English and Chinese. By the end
of the session, Dyna Craft person-
nel were confidently producing
a variety of primary parts (floors,
bulkheads and tank tops) using
infusion.
While the training took place
DIAB Technical Services’ engineers
prepared the laminate design for
hull and deck of one of the smaller
vessels that the company builds.
The DIAB and Dyna teams then
communicated back and forth to
finalize the scantlings and set the
date for the first hull infusion.
InfusIng the fIrst hull
When all the materials were in
place and the equipment ready,
two DIAB engineers, together with
local distributor Port King, arrived
to oversee the set-up and infusion
of the first hull and deck - a five day
program. All ran smoothly and the
hull was infused on the evening of
the fourth day. The hull had a single
skin bottom and by removing the
CSM (chopped strand mat) content
from the laminate and replacing
some laminate with CFM ( continu-
ous filament mat) no surface flow
medium was required and it was
possible to place the resin lines
well apart. This allowed for a simple
set-up in the hull bottom area, with
few feed points and lines. The top-
sides were cored so only one feed
line was required along each chine
to infuse the hull all the way to the
shear line. Total infusion time was
Infusing the Perfect Partnership
about 100 minutes. On the fifth day
the fully-cored deck was infused
without any problems.
The yard has since completed
four vessels of this type. One of the
biggest gains has been the fact
that the hulls and decks are now
being de-molded with a high level
of finish and no print-through (even
on dark colored hulls) thanks to the
print barrier system introduced by
DIAB Technical Services.
Since the first infusion, DIAB
have been on site a further five
times in order to fine tune the pro-
cess and implement new ideas
such as kitting and re-usable lines
and connectors. The partnership
continues with the next stage be-
ing to look at infusing the stringers
at the same time as the hull. Also
Dyna Craft is evaluating this ap-
proach for its larger vessels which
range from the 15.5 meter (51 ft.)
Dyna Flybridge to the 23.5 meter
(77 ft.) Laguna.
www.dynacraftyacht.com
The hull molding at Dyna Craft ready to be infused.
DIAB ‘SOLUTIONS’ - SPRING 2007 - 5
AFRICAN CATS
When Dutch business-
man and experienced
sailor Gideon Goud-
smit couldn’t find a production
catamaran to meet his needs he
decided to start a company to
build his ideal boat. As a result Af-
rican Cats (Durban, South Africa)
was established to build pro-
duction catamarans that would
rewrite the ‘rule book’ in terms of
speed, handling, performance
and comfort.
In order to reduce weight
while at the same time increasing
structural strength, African Cats
has developed its own infusion
manufacturing system called Vec-
tor-K that uses lightweight/high
strength composite materials
(carbon, Kevlar, basalt and e-
glass reinforcements, Divinycell
core materials and epoxy resin).
As a result its sailing cats (which
range in length from 12.1 to 20.7
meters [40-68 ft.]) are almost
50% lighter than the competi-
tion. Although saving weight was
the primary goal, the company
maintains that safety has never
been compromised to achieve
it. All boats are CE certified by
ECB and, of course, a lighter boat
means a lower center of gravity
for added safety. In addition the
use of Kevlar in the hulls greatly
improves impact resistance.
African Cats light weight/high
strength philosophy is not just
confined to the main structure of
its cats. One example is where
African Cats has broken with
tradition by not using a gel coat
on the outer skins or a flow coat
on the insides of the boat. As
any experienced boat owner can
tell you a gel coat is a relatively
fragile covering, easy to scratch
and difficult to repair. Instead
of a gel coat, African Cats uses
a much tougher polyurethane
paint. Not only is it much easier
to color match and repair but it
also saves a significant amount
of weight - in the case of the
company’s 435 model over 500
kilos (1,100 lb.) - 12% of the total
weight of the boat!
Re-writing the ‘Rule Book’
An African Cat 435 which is now available in a fossil fuel-free version.
Continuous development is
very much the watchword at
the company. Last year African
Cats introduced the world’s first
fossil fuel-free, production sailing
yacht which uses a combination
of dual wind generators and so-
lar panels to charge its batteries.
With the lithium-ion battery op-
tion, the cat’s electric motor can
be run continuously for six hours
at 50% power. Top speed of the
13.16 meter (43 ft.) long vessel
is 8 knots under power and 20
knots under sail. Sailing at just
5 knots is sufficient to re-charge
the batteries.
www.africancats.com
MAR
INE
DIAB ‘SOLUTIONS’ - SPRING 2007 - 6
Since being established
in 1970 Faaborg Værft
has grown to become
Denmark’s leading builder of com-
mercial FRP vessels.
Initially the company concen-
trated on pleasure craft but over
a relatively short space of time the
emphasis was switched to fishing
boats and special purpose ves-
sels.
In 1979 Faaborg Værft took
over the Jupiter shipyard at Bogø
on Møn, together with the rights to
the boat type of the same name.
Over time it developed the Jupiter
models into various types of work
boats including inspection boats
for the German River Police.
The recession in the fishing in-
dustry has meant that a large part
of its production and repair work
in recent years has been directed
towards other areas. Typically
Faaborg’s customers have been
government and municipal authori-
FAABORG VAERFT A/S
ties such as the Danish Pilotage
Authority, the Danish Environmen-
tal Protection Agency, the Royal
Danish Navy and six of Denmark’s
counties.
Faaborg still continues to pro-
duce fishing vessels ranging in
length from 12 to 25 meters (40
to 82 ft.)
One of the company’s latest
contracts is from the Danish Naval
Material Command for the supply
of six Standardfartøj MK II patrol
ships that will replace the BARSØ
class vessels that have been in ser-
vice for over 40 years. Each ship
is 43 meters (141 ft.) long and has
a beam of 8.2 meters (27 ft.).
Delivery of the first ship to the
Royal Danish Navy will take place
in July this year with the remaining
five vessels being commissioned
over the next two years.
The hull, deck, superstructure
and interior of the vessels are
primarily FRP sandwich based on
Divinycell cores. Although Faaborg
is the prime contractor, it has sub-
contracted the hull moldings to
Kockums AB in Sweden (builder
of the Visby ‘Stealth’ Corvette).
After installation of the propulsion
system, the hulls are transported
to Faaborg Værft A/S for outfitting
and delivery to the Royal Danish
Navy.
www.faaborg-vaerft.dk
Two of the six 43 meter (141 ft.) vessels that Faaborg is producing for the Royal Danish Navy.
A Faaborg 36 fishing boat.
Denmark’s Leading Commercial FRP Shipbuilder
DIAB ‘SOLUTIONS’ - SPRING 2007 - 7
A B
C
MUNDAL BÅT AS
Sayer Moves to Core Infusion
Mundal Båt AS is one of Norway’s
leading builders of FRP sandwich
vessels. The company was es-
tablished in 1981 by brothers Atle
and Nils Landro who recognized
that the light weight/high strength
and corrosion resistant attributes
of composites were ideal for fish-
ing vessels.
To date Mundal has built and
delivered over 38 commercial
vessels using Divinycell sandwich
construction. In addition it has
re-built/expanded a further 15
vessels, again using sandwich con-
struction. It now offer vessels up to
33.5 meters (110 ft.) in length. The
company uses a variety of com-
posite manufacturing techniques
and has recently introduced DIAB
Core Infusion Technology™.
In addition to its commercial
boat building work, Mundal has
expanded its activities to include
the production of a variety of sand-
wich composite components for
offshore oil and gas and sub-sea
applications. These include guided
drogues and sub-sea buoyancy
units.
www.mundal.no
‘Bluefin’ a 27.1 meter trawler built by Mundal Båt AS.
Led by the well-known sailor-de-
signer-builder, Jon Sayer, Sayer
Yachting Services specializes in
custom design and construc-
tion. Based in Mooloolaba on
Queensland’s Sunshine Coast in
Australia, SYS has recently made
its first foray into infusion molding
with the production of two 12 meter
(39 ft.) race boats that have been
designed primarily for the Mel-
bourne to Osaka Double Handed
Yacht Race.
The original plan was to use
vacuum bagging but having at-
tended one of DIAB’s Core Infusion
Technology™ courses Jon Sayer
decided that infusing the boat and
thermoforming the core was the
way to go.
Engineering was by EMP Com-
posites and infusion processing
The Jon Sayer-designed and built 12 meter ‘Wasabi’ about to leave the yard.
support by DIAB Technical Ser-
vices. The first boat, ‘Ryujin’ was
launched in July 2006 whereas her
sister hit the water in December.
Commenting on the switch, Jon
Sayer said, “There is little doubt
that this is a clean and cost-effec-
tive method for this type of boat.
We managed to fully impregnate
the 12 meter hull halves with ep-
oxy resin in 40 minutes and the
‘one shot’ approach saved a lot of
secondary bonding operations.”
He added, “Our biggest success
in the process was the use of DIAB
GPC1 pattern foam to provide the
correct resin transfer properties.”
www.sayerdesign.com
TECH
NICA
L SE
RVIC
ES Sandwich Panel Impact Performance
DIAB ‘SOLUTIONS’ - SPRING 2007 - 8
Introduction
The main difference between
laminates manufactured us-
ing vacuum infusion versus
hand lamination is the fiber volume
fraction. There are well known and
verified theories for predicting
global stiffness and strength of
sandwich panels. These theories
together with the rule of mixtures
can be used to study the influ-
ence of variations in fiber volume
fraction. However, without empiri-
cal testing it is difficult to predict
impact performance.
The aim of this study was to
investigate the difference in impact
performance between sandwich
skins manufactured using infusion
and hand lay-up. A secondary ob-
jective was to evaluate whether it is
possible to predict impact damage
with a quasi-static test.
test Panels
Two sets of test panels were
made. For the first, the ‘hand’ and
infused panels had the same fiber
lay up in order to study the direct
effect of the different manufactur-
ing processes. In the second test
series the manufacturing method
was taken into account when de-
signing the fiber lay-up thereby
providing a more ‘real world’ com-
parison scenario.
All the test panels comprised
a 20 mm core of Divinycell H130
with glass skins. An infusion grade
polyester resin was used for all of
the panels in order to prevent any
differences in resin properties ef-
fecting the results.
The fol lowing coding has
been used for the glass fiber
lay-up: CSM=Chopped Strand
Mat. Q=Quadriaxial symmetrical
distribution. B=Biaxial symmetri-
cal distribution 0/90 direction.
The number denotes the weight
in g/m2.
first test series
In both cases the lay-up (im-
pacted surface downwards) was
CSM 450 / Q 800 x 2 / 20 mm H130
/ Q 800 x 2. On the hand laminated
panel the fiber volume fraction was
0.32 whereas with the vacuum in-
fused panel it was 0.43. The outer
CSM fabric, which was hand laid
on both panels, was 0.14.
The sandwich panels were
designed and manufactured to
meet the requirements for a typi-
cal bottom panel of a 11.6 meter
(38ft.) power boat, according to
the preliminary ISO standard. With
the infusion process, the skins are
usually specified with a lower CSM
content due to the good skin to
core bond.
second test series
Starting from the outside of the
hull the lay-up for the hand lami-
nated panel was CSM 300 / CSM
450 / B 600 x 2 / CSM 450 / 20 mm
H130 / CSM 300 / B 800 x 2. The
vacuum infused panel had a lay
up of CSM 600 / B 800 x 2 / 20 mm
H130 / B 800 x 2.
The outer CSM layer was hand
laid to simulate a typical skin coat.
The fiber volume fractions were
0.27 for the hand laminated panel,
0.39 for the vacuum infused panel
and 0.15 for the CSM fabric that
was hand laid on both panels.
Outer skin thicknesses were 2.7
mm for the vacuum infused panel
and 4.3 mm for hand laid panel.
DIAB Technical Services has recently undertaken a study to evaluate the variations in impact performance of sandwich panels produced by hand laminating and infusion.
Carl-Johan Lindholm, M.Sc., reports on the main findings of the study.
The two ‘impactors’ that were used to simulate impacts from sharp and blunt objects.
DIAB ‘SOLUTIONS’ - SPRING 2007 - 9
Impact testing
The impacts were carried out
using a five meter (16.4 ft.) high
test rig from which a sled was
dropped. It was possible to vary
the height from which the sled was
dropped and the mass of the sled.
The kinetic energy applied to the
panel was calculated by using the
velocity (just before the sled hit the
panel) and the weight of the sled.
Two impactors were used to
simulate an impact from a sharp
and a blunt object. The sandwich
panels were placed on a rigid
steel plate to ensure that just the
local effects of an impact could
be studied.
Quasi-static testing
The quasi-static tests were
made using an Instron universal
testing machine. During the tests,
the force and position of the cross-
head was recorded. From the force
indention curve the energy loaded
onto the panel was calculated.
One type of damage is the
visual de-laminated area. In this
case the Quasi-Static testing was
carried out by stopping the inden-
tion in steps of 1 mm. At the end of
every step the load was recorded
and the panel unloaded and the
de-lamination area measured.
Conclusions
Comparing the two types of
panels, hand lamination and infu-
sion, the size of the de-laminated
area from a spherical impact was
similar for both panel types. It can
be concluded that even if the outer
skin of the vacuum infused panel
is 36% thinner and 27% lighter
than the hand laminated panel,
the resistance against a spherical
impact is likely to be the same. A
possible explanation is that with the
spherical impactor the stress state
in the skin may be dominated by
membrane stresses.
The visual damage (see below)
seems similar on the both panels
apart from the fact that the vacuum.
Infused panel tends to give slightly
larger de-laminations in the prin-
ciple direction of the fibers. This
may be because the infused panel
contains less randomly distributed
fibers than the hand laminated
panel.
Since the tensile properties of
the skins are designed to be simi-
lar, no difference in performance
was seen. In the case of the sharp
impactor, the hand laminated panel
showed slightly less indentation
compared to the infused panel at
the same load. The reason for this
may be that the thicker skins of
the hand laminated panel perform
better when the stress state is
dominated by bending and shear
stresses.
It appears that results from
quasi-static testing can be used to
predict the indentation depth from
a sharp impact with reasonable
precision. The results achieved
with the spherical impactor are not
as accurate, but may be sufficient
to provide a rough estimate of the
likely ‘real world’ performance.
Regarding the de-lamination
area from the spherical impactor,
quasi-static testing may be used to
indicate the size of the de-lamina-
tion area. However this is only valid
as long as the skin has not been
penetrated in the test.
A copy of the complete study (which in-cludes the full test results) is available free-of -charge from DIAB Technical Services.
The set-up for the quasi-static tests.
The two panels on the left show a spherical impact at 150 Joules (left: infused panel, right: hand lay-up panel). The two panels on the right show a ‘sharp’ impact at 150 Joules (left: infused panel, right: hand lay-up panel).
MAR
INE
DIAB ‘SOLUTIONS’ - SPRING 2007 - 10
WERNER PADDLES - SIMPLY THE BEST
WINNER OPTIMIST
Werner Paddles (Sultan, Wash-
ington State, USA) is recognized
as the world’s leading producer of
paddles for whitewater, touring and
canoeing use.
At the top end of Werner’s
various offerings is its Performance
Core lines which feature paddle
blades constructed using pressure
molded technology.
The form of the blade is initially
defined by the foam core blank
which is precisely CNC-milled to
create the correct shape and cur-
vature. Carbon and, depending on
the model, Kevlar reinforcements
are laid onto the core using epoxy
resin. Then, for added durability,
Werner molds a layer of Dynel
around the edge and a double
layer in the tip where the paddles
are prone to abuse. The complete
assembly is then loaded into a
custom-built, heated press to cre-
ate the final blade. The end result
is a technical blade design that
displaces water for a significantly
lighter, buoyant feel on the water.
The added buoyancy is excep-
tional for enhancing rolls in aerated
water, allowing stable bracing and
reducing effort in long paddle out-
ings.
www.wernerpaddles.com
If there is one thing that the majority
of Olympic sailors have in common
is that they started their sailing ca-
reer in an Optimist. Sailed in over
110 countries by over 150,000
young people, it is the only dinghy
approved by the International Sail-
ing Federation for sailors under 16
years of age.
Although ‘Opies’ are produced
by many builders around the world,
the Danish company Winner Opti-
mists ApS, which was founded in
1965, is not only one of the most
experienced builders but also one
of the most successful with 15
World and 18 Europeans titles.
With Winner’s emphasis on
using only the best materials and
the highest standards of crafts-
manship, many would argue that
Winner produce the best GRP
Optimist. It is certainly the only
one that comes with a five year hull
guarantee. Vacuum bag sandwich
construction based on Divinycell
cores is used for the hull with DIAB
providing CNC milled core kits that
meet Winner’s exacting specifica-
tion. Each dinghy is checked by an
independent measurer who takes
120 separate measurements that
must be within ±1 mm.
www.winneroptimist.dk
The Choice of Today’s & Tomorrow’s Champions
A young sailor heading downwind in a Winner Optimist.
A Werner paddle with foam-cored blades in action.
DIAB ‘SOLUTIONS’ - SPRING 2007 - 11
Jupiter Plast A/S is one of the
world’s leading producers of
composite components for
the major wind turbine companies
and train rolling stock manufactur-
ers. From its original base around
the Danish island of Bogø, it now
has facilities in Germany, the
United States and China.
A long term user of DIAB sand-
wich cores, Jupiter Plast takes an
integrated approach when it comes
to the production of composite
moldings. This encompasses
component design, laminate en-
gineering and analysis (including
Finite Element Modelling), process
development and complete supply
chain logistics.
A typical example of the ben-
efits of this approach to Jupiter’s
customers is the extensive devel-
JUPITER PLAST
opment work it has undertaken
regarding nacelles (housings) for
wind turbines.
With the move to more power-
ful machines (2 MW plus is not
uncommon today), the nacelles
have become very large indeed .
The 2 MW for example is 4 x 4 x 15
meters (13.1 x 13.1 x 49.2 ft). The
cost of transporting such large and
potentially heavy components can
be very high.
Due to a combination of lami-
nate optimisation, removal of steel
reinforcements and the use of a
bespoke RTM Lite manufacturing
process, Jupiter has been able to
cut nacelle weight by more than
half. In addition, the nacelles are
quickly assembled from a series
of modular components using a
patented assembly system that
was also developed by Jupiter.
Jupiter’s role has even extended
to designing the special transport
stillages (seen below) that reduce
shipping volume and allow a com-
plete nacelle to be supplied to the
customer in ‘flat pack’ form. It is
estimated that the ‘nacelle optimi-
sation’ work undertaken by Jupiter
has halved transportation costs.
www.jupiterplast.dk
A batch of Jupiter wind turbine nacelles mounted on their specially designed transportation stillages.
Installation of Vestas V90 wind turbine nacelle and spinner.
A World Leader in Wind Energy & Train Components
WIN
D EN
ERGY
ARKTOS CraftThe Ultimate ‘Go Anywhere’ Amphibious Craft
DIAB ‘SOLUTIONS’ - SPRING 2007 - 12
TRAN
SPOR
T
A USCG approved 52-Evacuee ARKTOS Evacuation Craft under going pilot training in the US Beaufort Sea.
There are many vehicles and
craft that claim to have ‘go
anywhere capability’ but
none can get close to the per-
formance offered by an ARKTOS
Craft. These unique Craft, which
are designed and manufactured by
ARKTOS Developments Ltd. (ADL)
of Surrey, BC, Canada, have the
highest level of all-round amphibi-
ous mobility in the world. Due to
their unique design ARKTOS Craft
have an unsurpassed ability to
climb from water to ice and ma-
neuver through ice-rubble fields,
significant side slopes, steep
grades, muskeg, quicksand and
any other water transition zones.
The original concept was to
develop a craft that could evacuate
personnel from offshore oil pro-
duction facilities in temperatures
down to -50°C (-122°F) in mixed
water/ice conditions, land-fast
ice-rubble fields, shear-zone ice
and high winds on any ice surface
of the Beaufort Sea. Evacuation
is still one of the primary roles for
the ARKTOS Craft but today their
duties have been extended to
include fire fighting, geophysical
survey work and exploration in any
corner of the world irrespective of
the prevailing climatic condition or
the terrain.
ARKTOS Craft Enhancements The ARKTOS Craft concept
continues to be improved and
enhanced and today the mission
profile of the current evacuation
model includes evacuee survival
in the H2S gas clouds and burning
oil slicks that might be encountered
during the evacuation of bottom
founded oil rigs plus the ability to
remain afloat after damaging the
integrity of either of the hulls in ice
infested waters.
Successful tests of these en-
hancements, amongst others,
were required by the United States
Coast Guard (USCG) to approve
the 15.24 meter (50 ft.) ARKTOS
Craft for evacuation of 52 people
from bottom founded offshore
islands.
Although the existing 15.24
meter (50 ft.), USCG approved,
ARKTOS Evacuation Craft can
carry 52 evacuees or 5,000 kilo-
grams (11,000 lb.) of cargo through
the most severe terrain and up to
10,000 kilograms (22,000 lb.) of
cargo in open water, larger ver-
sions with a capacity of up to 150
evacuees are being developed.
Amphibious ARKTOS Crane Craft
and Amphibious ARKTOS Tugs ( to
tow Hover Barges) are also on the
‘drawing board’.
The ARKTOS Craft comprises
a permanently linked pair of sand-
wich composite hulls or units
as they are called. Each hull is
independently powered by its
own diesel engine. On ice or land
motive power is provided by the
tracks, while in water, propulsion
jets supply the required thrust.
A hydraulically powered ar-
ticulation arm links the two hulls,
or units.
Articulation control is achieved
by logic circuits operated through
a joystick allowing each unit to
operate at independent angles
with three axis of motion. This gives
ARKTOS Craft exceptional mobility
while moving across the interface
between dissimilar footings such
as the transition from water to ice,
land to ice, land to water, muskeg,
and land to quicksand. The ar-
ticulation arm also allows ARKTOS
DIAB ‘SOLUTIONS’ - SPRING 2007 - 13
Four ARKTOS Evacuation Craft on stand by on a man-made island in the Northern Caspian Sea that is seasonally surrounded by ice.
Fosieplast Moves To Infusion for Fire Truck Tank/Bodies
Craft to negotiate the irregular ter-
rain in ice-rubble fields, ice ridges,
abrupt drop-offs, side slopes and
most other hostile terrain.
The DIAB Technical Services
team has recently been heavily
involved in assisting ADL to re-
duce the weight and increase the
strength of the hulls, decks, struc-
tural-bulkheads, drive-wheel
boxes, nose idler-wheel boxes
and water-tight hatches, etc. par-
ticularly in terms of the crushing
and abrasive forces that can be
exerted when an ARKTOS Craft is
traversing ice floe formations. This
has involved re-engineering the
laminates (which now comprise a
combination of E-glass and Kev-
lar fabrics over a DIAB sandwich
core) and introducing DIAB Core
Infusion Technology™. As a result
of the new laminate specification,
ADL has removed the original steel
reinforcements without any loss of
structural integrity.
DIAB Tech Services also car-
ried out a series of flow modelling
exercises to determine the ideal
infusion set-up and was then on
site to assist the ADL production
team with the set-up and infusion
of the first hull, deck and structural
bulkhead moldings.
ADL has since produced a
further three unit sets of moldings
and reports that it is saving more
than one drum of resin per unit set
by using infusion.
www.arktoscraft.com
The complete rear end of of this fire truck is a sandwich composite molding.
Fosieplast AB (Arlöv, Sweden)
has been manufacturing
sandwich composite fire
truck tanks since 1977. Not only
are the sandwich tanks lighter and
stronger than an equivalent metal
unit they are also considerably
superior in terms of corrosion and
chemical resistance.
Although described as a tank,
the component that Fosieplast ac-
tually manufactures is much more
complex. In fact, it is (as can be
A tank/body in the final stages of manufacture.
seen here) the complete rear end
of the fire truck that is mounted
directly onto the chassis. Recently
the company has started to switch
from hand laminating to an infusion
process. This has multiple benefits.
The resulting laminates have much
higher fiber fractions than would be
the case with hand laminating and
therefore are stronger and lighter.
In addition, elapsed production
time is halved and the resulting
moldings have a much better sur-
face finish.
Another benefit of the process
for Fosieplast is that it now finds it
much easier to recruit personnel.
www.fosieplast.se
DIAB ‘SOLUTIONS’ - SPRING 2007 - 14
ULTRA-PORTABLE CARBON FIBRE SATELLITE TRANSMISSION DISHES
A rear view of the main dish that shows the special latching system.
INDU
STRY
The main dish and sub-reflector of the satellite transmission system.
Carbonia Composites AB
(Malmö, Sweden) special-
izes in the production of
high precision, composite compo-
nents using primarily carbon fiber,
specially-formulated epoxy resins,
Divinycell cores and a proprietary
resin transfer molding (RTM) pro-
cess.
For one of its major projects
it acts as a development partner
and supplier of components for a
new class of ground-breaking, ul-
tra-compact satellite transmission
systems. They are used by leading
broadcasters around the world as
well as several defense organiza-
tions including the US Special
Operations Command.
The transmission systems are
the smallest and lightest units
that are approved by all the major
commercial satellite operators. Key
design features of the units include
the ability to be carried and set up
in minutes by one person (who is
not expected to be a satellite com-
munications specialist) irrespective
of the location and the climatic
conditions.
To achieve the required levels
of signal accuracy (less than 3°
of arc), portability and reliability,
extensive use has been made of
carbon fiber sandwich compos-
ites for the main reflector, the sub
reflector and the transit case.
The requirement for the system
to retain its transmission accuracy
under potentially very difficult oper-
ating conditions (-40°C to +100°C
[-104°F to +212°F]) has meant that
the Carbonia components have
to be manufactured to an overall
tolerance of ±0.6 mm. (In fact, the
sub-reflector is made to accuracy
+0.05 mm.) Achieving this level of
accuracy is further complicated
by the need for the main 900 mm
diameter dish to be dismantled into
four separate pieces after use so
that it is truly hand-portable.
Carbonia also designed and
developed the special ‘latching
system’ that locks together the four
elements that make up the main
reflector (dish).
Such is the design of the sys-
tem that the four elements can be
locked together in seconds without
any adjustments being required or
for that matter allowed in case the
operator inadvertently introduces
errors into the system.
www.carbonia.se
DIAB ‘SOLUTIONS’ - SPRING 2007 - 15
SCHEMPP-HIRTH
A Schempp-Hirth Duo Discus. Photograph: J. Ewald.
AERO
SPAC
E
A Schempp-Hirth Discus-2c. Photograph: Wil Jannsens.
The name of Schempp-
Hirth Flugzeugbau GmbH
(Kirchheim unter Teck, Würt-
temberg, Germany) is synonymous
with success in competitive gliding.
Its sailplanes have so far amassed
a total of 26 world championship
titles (40% of all the world titles
awarded to date). Schempp-Hirth
gliders have also won countless
European titles and over 50 USA
national titles. Despite being in
business for more than 70 years,
the company continues to break
records and new ground in terms of
glider design and development.
In December last year in Ar-
gentina Klaus Ohlmann set a new
world speed record, averaging
306 kmh (190 mph) over a 500
km (310 miles) out and return in
a Schempp-Hirth Nimbus-4DM.
This was quickly followed in Janu-
ary by Sigi Baumgartl who set a
new speed record of 156.3 kmh
(97.12 mph) over a 750 km (466
World Class Performance for Over Seventy Years
miles) triangle in Namibia in his
Schempp-Hirth Ventus cM/15m (15
meter wingspan). Not to be out-
done by the men, Anja Kohlrausch
achieved a women’s world triangle
distance record of 1,019 km (633
miles) in a Ventus-2cxT/15m (15
meter wingspan).
Schempp-Hirth maintains that
its success is due to a combina-
tion of factors that include futuristic
constructions, high build quality, a
complete understanding of com-
posite materials and, last but not
least, highly motivated and expe-
rienced personnel.
The production of Schempp-
Hirth gliders began in a municipal
building yard in Göppingen, Ger-
many in 1935. In 1938 the company
relocated to its present site at
Kirchheim unter Teck. In the 1960s
the company quickly moved from
wooden glider construction to
composites.
Today, all Schempp-Hirth glid-
ers feature sandwich composite
wings based on Divinycell cores
in order to achieve a strong, light-
weight and aerodynamic structure.
The current range of gliders and
motor gliders comprises models
covering the 15 and 18 meter (50
and 60 ft.) wingspan Standard
Class (Discus), 15 and 18 meter
(50 and 60 ft.) wingspan FAI Class
(Ventus), a two seater (Duo Discus)
and the Nimbus open class.
www.schempp-hirth.com
www.diabgroup.com
DIAB is the world’s largest producer of structural foam core materials with production facilities inSweden, Italy, Lithuania, the USA, China, Thailand, Australia and Ecuador.
AustraliaTel +61 (0)2 9620 9999Fax +61 (0)2 9620 9900
E-m: [email protected]
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E-m: [email protected]
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E-m: [email protected]
GermanyTel +49 (0)511 42 03 40
Fax +49 (0)511 42 03 438E-m: [email protected]
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E-m: [email protected]
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E-m: [email protected]
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E-m: [email protected]
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SandwichCompositeSledge
ItalyTel +39 0119 42 20 56Fax +39 0119 47 35 53
E-m: [email protected]
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E-m: [email protected]
Pictured here is the first rigid, habit-
able sledge seen in Antarctica. The
brainchild of Brazilian, Julio Fiadi, the
‘capsule’ was engineered by Barracuda Ad-
vanced Composites - DIAB’s distributor in Brazil
- using a combination of carbon and aramid
fibers over a Divinycell core.
As a result the sledge is very light (less than
22 kg. [48 lb.]) yet it is extremely strong. In
recent trials carried out by Julio at Patriot Hills,
Antarctica, it was able to withstand buffeting
by 130 km (90 mph) winds.
“It tended to rock a bit, even with me inside.
However, just like a sailing boat, it rotates to
face the wind.”, reports Julio. He added, “As
a result of the excellent insulation properties
provided by the Divinycell core, it was a very
comfortable +20°C (68°F) inside, despite the
outside temperature being -15°C (5°F).
Solar panels mounted on either side of
the craft will charge any electrical/electronic
equipment.
Julio is a very experienced polar explorer
having previously undertaken nine polar ex-
peditions including two visits to both the North
and South poles.
After further trials, Julio is aiming to carry
out a 1,200 km (746 miles) solo South Pole trip
in the near future. He will haul all his gear and
supplies inside the capsule and then use it as
a snug, safe haven when resting.
www.barracudatec.com.br
ThailandTel +66 (0)38 465 388Fax +66 (0)38 465 389
E-m: [email protected]
Julio Fiadi and his sandwich composite sledge that was engineered by Barracuda Advanced Composites.