Yacht Design Newsletter 3 - BMT Group

Issue 3 | Summer 2008
Yacht Design Newsletter
Project Véloce Pushes 40 knots
BMT Nigel Gee is excited to introduce
its patented Pentamaran concept to the
large yacht market .
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Forthcoming and recent events BMT’s Wind Tunnel Facility Trinity T051- 74m
March ‘08 - Dubai Boat Show
Sept. ‘08 - Monaco Yacht Show
Oct. ‘08 - Fort Lauderdale IBS
Nov. ‘08 - HISWA Symposium
Nov. ‘08 - Global Superyacht Forum
Recent activity and feature on
facility . . . . . . . . . . . . . . . . Page 3
ShipConstructor 2008 streamlines
design . . . . . . . . . . . . . . . . .Page 3

Welcome
The last 12 months has delivered ever more diverse and challenging projects that have seen our
workload grow further. Indeed our offices have expanded further in the last year and now span
four floors at our base in Southampton.
To keep a pace with this growth we continue to seek and employ some of the best engineers the industry has to offer as well as support those
in education via BMT’s excellent bursary and recruitment program .Whilst current work load is our main point of focus we maintain our look to
the future with internal research and development studies which have resulted in some new and innovative concepts . Our patented Pentamaran
concept is one such example .
However design is not our only skill and BMT’s consultancy continues to provide a broad range of services to the industry . Our wind tunnel facility
at Teddington in the UK has been busy testing a number of yacht projects in the last 12 months and a full feature on the facility can be found in
this edition . Additionally BMT’s SMARTPOWER system is featured, which is helping maximize the fuel efficiency of numerous vessels worldwide .
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Current Projects
130m Motor Yacht Concept Design
120m Motor Yacht Consultancy
95m Diesel Motor Yacht Detail Design
85m Diesel Motor Yacht Detail Design
80m Swath Yacht Concept Design
74m Diesel Motor Yacht Full Design
73m Motor Yacht Concept Design
73m Diesel Motor Yacht Plan Approval
70m Yacht Support Cat Class Design
43m Catamaran Class Design
43m Motor Yacht Concept Design
Open 60 Consultancy
Project Véloce Pushes 40 knots
BMT Nigel Gee is excited to introduce its
patented Pentamaran concept to the large
yacht market . Developed for high speed
applications the Pentamaran hull form
is a derivative of the stabilised monohull
concept featuring a long slender central
hull, hydrodynamically optimised without
the constraints of needing to be stable .
Stability is then provided by two pairs of
outriggers or ‘sponsons’ . Conventional
stabilised monohulls typically require
relatively deeply immersed and long
sponsons to meet damaged stability
requirements and these can incur
significant resistance penalties . The
Pentamaran overcomes this by having
two pairs of sponsons; a very short and
shallow pair aft and a forward pair clear
of the static water surface . These forward
sponsons only become immersed as
the vessel heels, consequently stability
characteristics are maintained with no
resistance penalty . The Pentamaran
offers a wide bodied stable platform with
outstanding seakeeping characteristics
whilst retaining minimum speed loss in
higher sea states .
BMT Nigel Gee has undertaken some
US$5 million worth of testing on numerous
Pentamaran designs and the technology
is now fully mature .
Project Véloce is based on a 130m
platform capable of over 40 knots . The
beam of 30m offers significantly more
internal area than on an equivalently sized
monohull leading to exceptional internal
spaces with true flexibility in configuration
of the layout .
The propulsion system features a
CODOG (Combined Diesel Or Gas)
plant producing approximately 44MW
of installed propulsive power delivered
via waterjets offering outstanding
manoeuvrability and acceleration . For
low and medium speed operation twin
20V8000 diesels are utilised providing
efficient long range operation whilst for
sprint speeds a single LM2500+ pushes
the speed beyond 40 knots .
Project Véloce represents a truly
innovative application of technology in the
large yacht market . Further development
of this design is currently underway .
Principal Particulars
LOA 130m
Bmax 30m
Draught 5m
Propulsion LM2500+, 2x MTU 20V8000
Speed 40 knots
Range 3500nm at 20 knots

Trinity Yachts Signed to BMT
When Trinity Yachts signed
their largest project to date
they came to BMT Nigel Gee
for the design. This striking
vessel styled by Evan Marshall
is at an advanced stage
of construction at Trinity’s
Gulfport shipyard.
Design Work on the 74m T051 (M/Y New Horizon) started in May of 2007 and
BMT Nigel Gee immediately undertook the design and optimisation of the hull
lines . Extensive model testing undertaken at Oceanic in Newfoundland verified
the excellent resistance and seakeeping characteristics that had been predicted .
BMT’s scope included the enhancement of the initial concept, class level and
detailed production design utilising ShipConstructor software . A unit build
philosophy has been adopted specifically tailored to enable Trinity to begin
construction at the earliest stage .
Having operated with ShipConstructor since 1998, BMT has extensive
experience in getting the best results from the software . Recent implementation
of the latest release (2008) has enabled BMT to further streamline its detail
production design process and reduce delivery times by taking advantage of
the software’s latest features . Together with the 3D pipe work and duct routing
package, also from ShipConstructor, BMT are supplying another complete and
fully integrated detailed production design project .
BMT Wind Tunnel
BMT’s wind tunnel facility, located in
Teddington, has undertaken a number of large
yacht projects in the last few months including
assessment and optimisation studies for an
85m and 76m design.
BMT Fluid Mechanics operates 3 major test facilities which
consist of a very large boundary layer wind tunnel suitable for
testing complete designs, a short test section wind tunnel with a
relatively high test speed used for model tests of 2-D structures
such as aerofoil sections, and a racecar/automotive wind tunnel
which has been responsible for 110 Grand Prix Wins and 7
Constructor Championships for McLaren between 1982 and
2002 .
Utilising its very broad experience in the aerodynamics of
marine vessels, BMT can offer cost effective investigation and
optimisation studies including;
• Wind and current forces
• Deck level wind environment
• Helideck wind environment (wind gradients and turbulence)
• Funnel emissions and exhaust plume dispersion
• Assessment of temperature profiles
• Ventilation in enclosed/open areas to verify ventilation strategies
The key facility for undertaking these studies is the boundary
layer tunnel which is of a closed return type with a 4 .8m x
2 .4m working section . Capable of simulating full atmospheric
boundary layer conditions a wind speed range between 0 .2
80m Engine Room ShipConstructor model
to 45 m/s can be achieved . These facilities are supported by
comprehensive data acquisition and instrumentation systems .
Additionally the company utilises Computational Fluid Dynamics
(CFD) for modeling internal and external flows that are not
reliably modeled at reduced scale in a physical model test . In
these cases the wind tunnel is used to provide reliable boundary
conditions for the CFD simulations .
With the recent amendments to the LY2 requirements for
helicopter decks on yachts there is an increasing need for more
fundamental aerodynamic studies to be undertaken and BMT
has significant experience and capability in the assessment of
marine helidecks for operability and compliance with national
and international guidelines . Importantly BMT has played a key
role in recent Civil Aviation Authority research to enhance the
safety of marine helicopter operations and has also played a
key role in the framing of certification requirements and design
guidance .
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Smart Yachts Use SMART POWER
A yacht’s operating efficiency is the sum of the engine, propeller and hull efficiencies. For a
yacht to operate at its most economic the prudent and environmentally conscious owner will
wish to be able to quantify the effects of negative parameters on the performance, such as hull
fouling, in order to optimise the period between hull or propeller cleaning.
SMART POWER is an advanced real time yacht performance monitoring and analysis tool. Utilising
touch-screen technology, the system continuously records the yacht’s speed, fuel consumption,
shaft rpm and torque together with navigational and environmental parameters in order to
present performance trends over time and help to identify remedial measures.
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BMT Regatta
In early June BMT Nigel Gee held a company regatta racing
off the Bramble Bank in the Solent. Chartering a fleet of nine
Hunter Sonar’s from the Island Sailing Club in Cowes the
event was blessed with champagne conditions. Entries from
BMT SeaTech and BMT Isis were also in the fleet and spring
tides demanded that consistent results and sound tactics were
essential to win the six race regatta.
The day started with a moderate northerly breeze and a series of windward leeward’s
were set by the race committee . Mischief, helmed by BMT Nigel Gee Project Manager
Matt Curthoys, sailed a consistent opening
half taking three firsts . After lunch the
south westerly sea breeze kicked in and
the results became more evenly spread
but Mischief held on to her lead to win the
regatta by a narrow margin .
A similar regatta will be run in 2009 and will
include entries from our customers .
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By providing the information to assess
the yacht’s performance trends over time,
SMARTPOWER can help improve overall
operating efficiency by assisting the yacht’s
master and engineers in:
Reducing fuel consumption
Increasing operating speed
Educating crew in the factors affecting speed/fuel
consumption
Timely main engine repair /operation
Optimising periods between hull and propeller cleaning
Assessing alternative paint strategies
If you think you have
what it takes to mount
a challenge for the
“Mainsail Cup” please
get in touch!
SMARTPOWER features include…
• Continuous readings of the instantaneous;
• Shaft powers
• RPM
• Yacht speed
• Wind speed and direction
• Ship’s heading
• Fuel flow rates
• Graphical comparison of instantaneous and historical data
(ship’s speed, shaft power, fuel consumption etc .)
• Graphical trends of ship speed v .s power over time
(highlighting fluctuations in draught, trim and possible hull
fouling or propeller degradation) .
Plan
Approval
Services
BMT have recently been
appointed to undertake
plan approval on a series
of large (>70m) twin screw
motor yachts.
The diverse skills of the group allow a
comprehensive service to be offered,
all coordinated through BMT Nigel
Gee . Detailed plan approval for
structural, mechanical and electrical
systems are being undertaken within
a demanding time frame and cover
specification
compliance,
class and flag
requirements
and best
practice .
BMT Nigel Gee Ltd
Tel: +44 (0)23 8022 6655
Fax: +44 (0)23 8022 8855
email: enquiries@bmtyachts .com
www .bmtyachts .com