Yacht Design

1
Yacht Design Technology

• Rules Regulations

2
Introduction

• Racing Rules
• Handicapping Systems
• Restricted Classes
• Design Manufacture Rules
• ISO
• Classification Societies
• AYF, ORC, RORC

3
Handicapping Systems

• Aim to provide mechanism for diverse yacht types
  to compete with the most skillful sailors
  winning.
• International Measurement System (IMS)
• International Rule Club (IRC)
• Performance Handicap Racing Fleet (PHRF)

4
IMS

• Administered by Offshore Racing Council (ORC)
  offshore racings governing body.
• Developed from aim to predict boat speed from
  first principles rather than using a formula.
• Predict speed in different wind speeds and points
  of sailing therefore score races on actual
  conditions experienced.
• Initiated through research into VPPs at MIT in
  1976 - H. Irving Pratt Ocean Race Handicapping
  Project.

5
IMS

• Three stages
• Hull measurement lines processing system.
• Performance prediction (VPP) to obtain yacht
  speed in 7 wind speeds and 10 true wind headings.
• Race scoring software based on assumed course and
  wind speed.
• Totally transparent process source code for VPP
  is available.

6
IMS - Certificate
7
IMS
8
International Rule Club (IRC)

• IRC developed from, and replaces, the Channel
  Handicap System (CHS) rating rule.
• CHS began in 1984 through Royal Ocean racing Club
  (RORC) and lUnion Nationale pour la Course au
  Large (UNCL).
• The rule algorithms are confidential to the two
  clubs. The theory being that the confidentiality
  of the rule prevents designers designing yachts
  to the rule and effectively prevents rapid
  obsolescence.

9
International Rule Club (IRC)
10
International Rule Club (IRC)

• Simple and cheap - A rating application form is
  printed in the IRC yearbook and is available on
  the web. Simply fill out form and send off with
  appropriate fee.
• Q. I'm thinking of making changes to my boat /
  sails / rig - how can I find out what effect
  these changes will have on the rating ? You can
  apply for a trial certificate. Because of the
  confidentiality of the IRC maths, RORC reserve
  the right to refuse to run trials in some
  circumstances.
• In 2003 5525 yachts rated under the system.

11
Performance Handicap Racing Fleet (PHRF)

• Aims like IRC to provide single rating number,
  but method is different.
• Began in 1958 in California, now over 100 fleets.
  
• Coordinated by US Sailing, by administered
  locally.

12
Performance Handicap Racing Fleet (PHRF)

• Based on observed performance, administered by
  local committees that determine yachts handicap.
• New boat seeking a PHRF is compared with similar
  boats in fleet and initially given harsh
  handicap. This may be eased in light of results.
• In small fleets may use a golf handicapping
  system in addition.

13
Grand Prix Rule Working Party

• RORC, ORC US Sailing aimed to develop new
  handicapping rule
• solely for out and out race boats
• will be accepted by both owners and race
  organisers around the world
• will produce boats that are exciting and
  desirable to sail.

14
Grand Prix Rule Working Party

• The new rule will use a simple VPP which is a
  means to predict a yachts speed, based upon
  physical principles
• The Rule will be tuned to reward performance and
  discourage compromised design

15
Restricted Classes

• Americas Cup
• International Rule
• Volvo 70s
• Open Classes

16
Americas Cup

• International Americas Cup Class (IACC) taken
  over from old 12m yachts.

L rated length S rated sail area DSP weight
(kg)/1025
17
Americas Cup
18
Americas Cup

• In reality design space becomes small
• No limit on stability but draft limit of 4m,
  hence very deep keels with maximising weight in
  bulb whilst minimising hull, rig and gear weight.
• High end of Length range.
• Narrow hulls.

19
Open Classes

• Simple restrictions open 50 ft 60 ft overall
  length
• Restrictions added amount of water ballast,
  water tight subdivision

20
Volvo 70

• Box Rule
• Canting keel, a choice of one or two
  centreboards, and a choice of one or two rudders.

21
International Rule

• International rule classes, the 6, 8 and 12
  metres have remained active throughout the 20th
  and into the 21st century .

R rating (m) d midship girth difference (m) L
length (m) S sail area (m2)
22
Design Manufacture Rules

• The 2004-2005 ISAF Offshore Special Regulations,
  in 3.03, state that Category 1 and 2 yachts shall
  be designed, built and significantly modified in
  accordance with either
• The EC Recreational Craft Directive for Category
  A
• The ABS Guide for Building and Classing Offshore
  Yachts.
• This is endorsed by Yachting Australia Blue Book

23
EU Directive on the Construction of Recreational
Craft

• Since 16th June 1998 any yacht sold in EU has to
  comply with EU Directive on the Construction of
  Recreational Craft.
• The Recreational Craft Directive is a trade
  directive that relies on external standards, for
  example ISO 12215.

24
ISO

• Application of ISO is not mandatory, but
  designers and builders find their use helps
  reduce design and production time as well as
  ensuring good quality.

25
ISO

• ISO 12215 Small Craft - Hull Construction
  and Scantlings
• Part 1 Materials Thermosetting resins,
  glass-fibre reinforcement, reference laminate
• Part 2 Materials Core materials for sandwich
  construction, embedded materials
• Part 3 Materials Steel, aluminium alloys, wood,
  other materials
• Part 4 Workshop and manufacturing
• Part 5 Design pressures, design stresses,
  scantling determination (Draft Version Only)

26
Classification Society Rules

• American Bureau of Shipping Guide for Building
  Classing Offshore Racing Yachts - 1994.
• Det Norske Veritas Tentative Rules for
  Certification and Classification of Boats 1997
• Germanischer Lloyd
• L gt 24m Certification Service including hull
  rigs
• 2.5 gt L gt 24m Yacht Certification Body. Carries
  out the functions resulting from the Directive
  for Recreational Craft (94/25/EC).

27
(No Transcript)