SIST EN ISO 12215-10:2021

SLOVENSKI STANDARD
01-januar-2021
Mala plovila - Konstrukcija trupa in zahtevane lastnosti - 10. del: Obremenitve in
pritrditve ladijske opreme na jadrnici (ISO 12215-10:2020)
Small craft - Hull construction and scantlings - Part 10: Rig loads and rig attachment in
sailing craft (ISO 12215-10:2020)
Kleine Wasserfahrzeuge - Rumpfbauweise und Dimensionierung - Teil 10:
Takelagelasten und Takelagezubehör von Segelbooten (ISO 12215-10:2020)
Petit navires - Contruction de la coque et échantillonnage - Partie 10: Charges dans le
gréement et points d'attache du gréement dans les bateaux à voiles (ISO 12215-
10:2020)
Ta slovenski standard je istoveten z: EN ISO 12215-10:2020
ICS:
47.020.10 Ladijski trupi in njihovi Hulls and their structure
konstrukcijski elementi elements
47.080 Čolni Small craft
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 12215-10
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2020
EUROPÄISCHE NORM
ICS 47.080
English Version
Small craft - Hull construction and scantlings - Part 10: Rig
loads and rig attachment in sailing craft (ISO 12215-
10:2020)
Petit navires - Contruction de la coque et Kleine Wasserfahrzeuge - Rumpfbauweise und
échantillonnage - Partie 10: Charges dans le gréement Dimensionierung - Teil 10: Takelagelasten und
et points d'attache du gréement dans les bateaux à Takelagezubehör von Segelbooten (ISO 12215-
voiles (ISO 12215-10:2020) 10:2020)
This European Standard was approved by CEN on 22 February 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 12215-10:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 12215-10:2020) has been prepared by Technical Committee ISO/TC 188 "Small
craft" in collaboration with CCMC.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2021, and conflicting national standards shall be
withdrawn at the latest by May 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 12215-10:2020 has been approved by CEN as EN ISO 12215-10:2020 without any
modification.
INTERNATIONAL ISO
STANDARD 12215-10
First edition
2020-11
Small craft — Hull construction and
scantlings —
Part 10:
Rig loads and rig attachment in
sailing craft
Petit navires — Construction de la coque et échantillonnage —
Partie 10: Charges dans le gréement et points d'attache du gréement
dans les bateaux à voiles
Reference number
ISO 12215-10:2020(E)
©
ISO 2020
ISO 12215-10:2020(E)
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

ISO 12215-10:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 3
5 Application of the document . 4
5.1 General . 4
5.2 The simplified method . 4
5.3 The developed method . 4
5.4 Steps of the methods and corresponding clauses of this document . . 5
6 Simplified and developed methods — Design stresses . 6
6.1 General . 6
6.2 Design load vs safety factor . 7
7 Developed method — General assessments, design moment . 8
7.1 General . 8
7.1.1 General topics on rigging design . 8
7.1.2 Sail configurations: . 9
7.1.3 Rigging loads and adjustment information to be provided . 9
7.2 Design moment M : righting or heeling moment .10
D
7.2.1 General.10
7.2.2 Principle of design .10
7.2.3 Topics on multihulls/form stable sailing craft corresponding to case b) i.e.
with M < M .13
H1 R UP1
7.2.4 Downwind longitudinal force F and nose trimming moment
ADOWN
M , running under spinnaker alone — "Normal" (S ) or
HDOWN c6
"exceptional" (S ) .14
c8
7.2.5 Maximum righting moment M , exceptional case, reaching under
RMAX
spinnaker .14
7.2.6 Heeling force F and heeling moment M while broaching
ABROACH HBROACH
under spinnaker, exceptional case .14
7.2.7 Minimum sail configuration and righting/heeling moment to be analyzed .14
7.3 Rig dimensions, and default values for areas, forces and points of application .15
7.4 Wing masts .21
7.5 Resultant forces in sails .22
8 Loads in rigging elements — Developed method .23
8.1 General .23
8.2 Force in forestay, inner forestay, mainsail leech and on halyards .23
8.2.1 General.23
8.2.2 Force in forestay, inner forestay, mainsail leech and on halyards connected
with sag .24
8.2.3 Force in forestay to balance the longitudinal component of forces from aft
set shrouds, fixed/running backstays, mainsail leech .24
8.3 Force in backstay, running backstays, or equivalent .24
8.3.1 General.24
8.3.2 Fractional rig with fixed backstay, no running backstay and aft angled
spreaders .25
8.3.3 Case of rigs without fixed nor running backstay .25
8.4 Compression in the mast step/pillar .27
8.4.1 General.27
8.4.2 Initial mast compression due to pre-stressing .27
ISO 12215-10:2020(E)
8.4.3 Mast compression due to heeling or broaching .28
8.4.4 Design compression in the mast step/pillar .28
8.4.5 Detail topics on mast step/pillar .28
8.5 Final design load on rig elements .28
9 Structural components to be assessed — Simplified or developed method .29
9.1 General .29
9.2 Mast steps and mast pillars and their connection to the craft's structure .29
9.3 Chainplates and their connections to the craft's structure.29
9.4 Design details of chainplates and their connection to the structure .30
9.4.1 General.30
9.4.2 Strapped FRP chainplates .30
10 Application of the simplified method .31
11 Application of the developed method .31
11.1 General .31
11.2 General guidance for assessment by 3-D numerical procedures .31
11.2.1 General.31
11.2.2 Material properties .32
11.2.3 Boundary assumptions .32
11.2.4 Load application .32
11.2.5 Model idealization .32
11.3 Assessment by ‘strength of materials’ based methods .32
12 Application of this document .32
13 Information in the owner's manual .32
14 Information to the boat builder .33
Annex A (informative) Application sheet of ISO 12215-10 .34
Annex B (informative) Information on metals and bolts .36
Annex C (normative) Simplified "established practice" for mast step/pillar assessment .40
Annex D (normative) Simplified "established practice" for the assessment of
chainplatesand their connection .47
Annex E (informative) Simplified "established practice" calculation oftransverse rig
elements — Examples .69
Bibliography .77
iv © ISO 2020 – All rights reserved

ISO 12215-10:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by ISO/TC 188, Small craft.
A list of all parts in the ISO 12215 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
ISO 12215-10:2020(E)
Introduction
The reason underlying the preparation of the ISO 12215 series is that scantlings rules and recommended
practices for small craft differ considerably, thus limiting the general worldwide acceptability of craft.
This document has been set towards the minimal requirements of the current practice.
The dimensioning according to this document is regarded as reflecting current practice, provided
the craft is correctly handled in the sense of good seamanship and equipped and operated at a speed
appropriate to the prevailing sea state.
This document is not a design standard and designers/builders are strongly cautioned from attempting
to design craft such that nearly all structural components only just comply.
The connection between the rig attachment and the structure is required to be stronger than the rig
attachment itself. It is therefore considered that unforeseen overload will not entail its detachment
from the structure, and that the watertight integrity will be maintained.
vi © ISO 2020 – All rights reserved

INTERNATIONAL STANDARD ISO 12215-10:2020(E)
Small craft — Hull construction and scantlings —
Part 10:
Rig loads and rig attachment in sailing craft
1 Scope
This document specifies methods for the determination of:
— the design loads and design stresses on rig elements; and
— the loads and scantlings of rig attachments and mast steps/pillars;
on monohull and multihulls sailing craft.
It also gives, in Annexes, "established practices" for the assessment of mast steps/pillars or chainplates
NOTE 1 Other engineering methods can be used provided the design loads and design stresses are used.
This document is applicable to craft with a hull length L up to 24 m but it can also be applied to craft up
H
to 24 m load line length.
NOTE 2 The load line length is defined in the OMI "International Load Lines Convention 1966/2005", it is
smaller than L . This length also sets up, at 24 m, the lower limit of several IMO conventions.
H
Scantlings derived from this document are primarily intended to apply to recreational craft, including
charter vessels.
This document is not applicable to racing craft designed only for professional racing.
This document only considers the loads exerted when sailing. Any loads that may result from other
situations are not considered in this document.
Throughout this document, and unless otherwise specified, dimensions are in (m), areas in (m ), masses
2 2
in (kg), forces in (N), moments in (N m), stresses and elastic modulus in N/mm (1 N / mm = 1 Mpa).
Unless otherwise stated, the craft is assessed in fully loaded ready for use condition.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 12215-5:2019, Small craft — Hull construction and scantlings — Part 5: Design pressures for monohulls,
design stresses, scantlings determination
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
ISO 12215-10:2020(E)
3.1
design categories
description of the sea and wind conditions for which a craft is assessed to be suitable
Note 1 to entry: The design categories are defined in ISO 12217 (all parts).
Note 2 to entry: The definitions of the design categories are in line with the European Recreational Craft Directive
2013/53/EU.
[SOURCE: ISO 12215-5:2019, 3.1]
3.2
loaded displacement
m
LDC
mass of water displaced by the craft, including all appendages, when in the fully loaded ready-for-use
condition
Note 1 to entry: The fully loaded ready-for-use condition is further defined in ISO 8666.
[SOURCE: ISO 12215-5:2019, 3.2]
3.3
sailing craft
craft for which the primary means of propulsion is wind power
Note 1 to entry: It is further defined in ISO 8666.
[SOURCE: ISO 12215-5:2019, 3.3, modified — Note 2 to entry deleted.]
3.4
monohull
craft with only one hull
3.5
multihull
craft with two or more hulls with a connecting wet deck/platform or beams above the loaded waterline,
as opposed to a tunnel boat or scow
3.6
mast step
element fitted at the bottom of the mast that supports the mast compression and transmits it to the rest
of the structure
3.7
mast pillar
pillar
in a deck stepped rig, structural element that transmits the mast compression to the rest of the
structure
3.8
chainplate
rig attachment
component(s) to which the rig elements are attached, transmitting their load to the rest of the structure,
including tie rods where relevant
EXAMPLE Metal chainplate, strapped composite chainplate,
Note 1 to entry: See Annex D.
2 © ISO 2020 – All rights reserved

ISO 12215-10:2020(E)
3.9
connection
all elements or group of elements connecting the rig
attachment to the structure of the craft
EXAMPLE Bolts, lamination.
Note 1 to entry: Some of these elements can be part of the chainplate.
3.10
m condition
LDC
maximum load condition corresponding to the loaded displacement (3.2)
4 Symbols
Unless specified otherwise, the symbols, factors and parameters given in Table 1 apply.
Table 1 — Symbols, factors, parameters
Symbol Unit Designation/Meaning of symbol Reference
1 - Main dimensions of the craft
Beam between centers of buoyancy: between center of buoyancy of
B m hulls, for catamarans; and between C of center hull and C of float, for Table 5, Fig 3
CB B B
trimarans
B m Beam between chainplates (from port to starboard) Table C.1, Fig 3
CP
B m Beam of hull It 1 of Table 5
H
GZ m Righting lever at 30° heel for monohulls Table 5
L m Length of waterline in m condition 7.5, Table 10
WL LDC
V m Height of craft center of gravity above T bottom Table 5, Fig 3
CG C
m kg Loaded displacement mass (3.2) or condition (3.10) 3.2, Clause 13
LDC
n 1 Number of persons hiking It 1 of Table 5
PH
T m Draught of canoe body Table 5, Fig 3
C
2 - Main dimensions of the rig and connected data
A m Sail area, index i defining the sail name or combination Tables 5 to 8 etc.
i
F N Aerodynamic force, index i defining which force it corresponds to Tables 5 to 8
Ai
F N Design compression force on single mast step/pillar 8.4. Annex C
DMC
Design compression force on mast step/pillar of two-masted rig where
F N 8.4. Annex C
DMCi
index i = 1 or 2
M Nm Design moment under sail Tables 5 and 6
D
M Nm Heeling moment, where index i = , , Tables 5 and 6
Hi UP MAX, BROACH,DOWN
M Nm Righting moment, where index i = , ϕ , Table 5
Ri UP UP MAX
Design apparent wind speed, in knots, at the center of area of sails,
V knots Tables 5 and 7
ACEK i
where index i stands for sail configuration S
Ci
Design apparent wind speed, in m/s, at the center of area of sails,
V m/s Tables 5 and 7
ACEM i
where index i stands for sail configuration S
Ci
m/s Design apparent wind speed at mast top, where index i stands for sail
V Note 5 in Table 5
AMT i
(knots) configuration S
Ci
See Table 8 for detailed dimensions of rig, areas, etc.
ISO 12215-10:2020(E)
Table 1 (continued)
Symbol Unit Designation/Meaning of symbol Reference
3 - Factors
k 1 Design category factor for rig It 5 of Table 3
DCR
k 1 Dynamic sail and rig factor It 1 of Table 10
DSR
k 1 Foresail center of pressure height factor It 1of Table 9
HF
k 1 Mainsail center of pressure height factor It 3 of Table 9
HMS
k 1 Load case factor Tables 3 and 7
LC
k 1 Material factor It 3 of Table 3
MAT
k 1 Roach factor Table 8
ROACH
k 1 Forestay or inner forestay sag factor = stay sag sagitta/stay length It 3 of Table 10
SAGF
k 1 Mainsail leech sag factor It 3 of Table 10
SAGM
k 1 Factor assessing heel angle of multihulls It 1 of Table 5
ϕ
4 - Other variables
S 1 Sail configuration where i is the configuration index Table 7
Ci
S 1 Safety factor against i, the index i being y (yield) or u (ultimate) Table 4
Fi
σ ,, τ N/mm Direct or shear stress, where i may be LIM, u, uw, yw, uc, ut, uf Table 3
i i
ϕ degree Heel angle, which may be 30° for monohulls or ϕ for multihulls Table 5
LIM
5 Application of the document
5.1 General
This document allows the determination of the design loads and design stresses on rig elements
of sailing small craft and to assess the design loads on mast step/pillar and chainplates and their
connection to the craft's structure:
1) by a simplified method, or
2) by a developed method.
These methods are defined step by step in Table 2.
The developed method also allows to determine the rig loads needed to assess the global loads in the
structure of multihulls in ISO 12215-7:2020.
5.2 The simplified method
Clause 14 requires that the mast/rig manufacturer provide the design load on mast steps/pillars and
on each rig element, the dimensions of end fittings, etc. assessed according to 7.1.3. If this information
is not available, the "Simplified method" applies through "Established practice" Annexes: Annex C for
"basic" or "enhanced" methods for mast steps/pillars, or Annex D for chainplates or their connections.
5.3 The developed method
This method involves the full determination of the design loads on mast steps/pillars and on each rig
element, the dimensions of end fittings, etc. assessed according to Clause 7. The assessment of the mast
step(s), mast pillar(s), chainplates, and their connections to the craft shall then be checked either by the
4 © ISO 2020 – All rights reserved

ISO 12215-10:2020(E)
"Established practice" methods of Annexes C and D or by any relevant engineering method, including
finite elements methods (FEM).
NOTE The actual dimensioning of mast and rig being a complex mast bending and buckling problem, where
the tuning of rig elongation is paramount, mast scantlings are purposely left out of the scope of this document,
even if the values of the loads defined is a useful information.
5.4 Steps of the methods and corresponding clauses of this document
Table 2 sums up the steps for both methods and gives the corresponding Clauses of this document.
Table 2 — Assessment methods
Step Methods Clause & Table
1- SIMPLIFIED METHOD for mast step/pillar or chainplate 5.2
1.1 Design stress determination Clause 6 and Table 3
If no information is available from the mast/rig manufacturer/provider, the
"Established practice" methods of Annex C -"basic" or "enhanced"- allow a sim-
1.2 ple determination of the design compression force F and scantlings of mast Annex C
DMC
steps/pillars and their connections to the structure. Tables C.4 and C.5 also give
examples of mast step/pillar floor calculation according to the design force.
1.3 For chainplates and their connection, use the "Established practice" of Annex D Annex D
1.4 Structural components to be assessed – mast step or chainplate Clause 9
1.5 Use of the Annexes for the simplified method Clause 10
1.6 Application of this document and application sheet Clause 12, Annex A
1.7 Information in the owner's manual Clause 13
1.8 Information to be given to the boatbuilder from rig/mast manufacturer/provider Clause 14
2- DEVELOPED METHOD for rig load, mast step/pillar or chainplate
5.3
Computation of all the loads in the rig
2.1 Design stress determination Clause 6 and Table 3
Developed method - General assessments, design moment Clause 7 and:
Determination of the design moments/forces according to sail configuration S :
Ci
— Formulas for the determination of upwind design moments and forces 7.2 and Table 5
— Formulas for the determination of downwind design moments and forces 7.2 and Table 6
2.2
— Sail configurations, design heeling/righting moments and apparent wind
7.2 and Table 7
speed
— Rig dimensions and default values for dimensions, areas and point of
7.3 and Table 8
application
— Transverse forces on sails 7.5 and Table 9
Design loads in rigging elements: Clause 8 and:
2.3 — Forces in forestay, inner forestay, mainsail leech and halyards 8.2 and Table 10
— Forces in backstay or running backstay or equivalent 8.3 and Table 10
2.4 Structural components to be assessed – mast step or chainplate Clause 9
2.6 Application of the developed method Clause 11
2.7 Application of this document and application declaration Clause 12, Annex A
2.8 Information in the owner's manual Clause 13
2.9 Information to the boatbuilder Clause 14
ISO 12215-10:2020(E)
6 Simplified and developed methods — Design stresses
6.1 General
The design stresses defined in Table 3 shall be used.
NOTE They are similar to those used in ISO 12215-9:2012, except that the dynamic factor for rig k
DSR
increases the loads for light craft and therefore have a "dynamic behavior", see Item 1 of Table 10.
This document differentiates two types of load cases: "Normal" and "Exceptional", see 7.1, which means
two different design stresses.
The stresses are obtained by multiplying, where relevant, see Tables 2 and 3, the actual stresses σ ,
act
τ etc. by k , and they shall not be greater than the design stresses σ , τ , etc.
act, DSR d d
The “limit” stresses σ or τ are given in Table 3 and correspond to the following stress states:
LIM LIM
— for metals, the one-letter subscripts for the stresses below are: y, for yield, and u, for ultimate; the
second character of the two-letter subscripts is w, for welded state within heat affected area (see
table footnote a in Table 3),
— for FRP and wood, the second character of the subscripts, u, means ultimate stress; the first character
respectively is t, for tensile, c, for compressive, and f, for flexural or bearing stress.
The sources for the values of these stresses, i.e. σ σ or τ for non-welded metals, or σ σ or τ for
y , u u yw , uw uw
welded metals in heat affected zones, or σ , σ , σ σ or τ for wood and FRP shall be:
tu cu fu, bu u
— either the "default" values according to Annexes B or D or to written data provided by the rig
manufacturer/provider;
— for other metals than the ones used in rig, according to Annex B for the listed metals, or documented
values for other metals, from a recognized standard, or from tests made according to a recognized
standard;
— for FRP or wood/plywood, respectively according to Annexes C or F of ISO 12215-5:2019.
Table 3 — Design stress and adjustment factors
1 - Design stress
σ or σ = σ × k × k × k , or τ = τ × k × k × k at yield, or ultimate, and bearing, as rele-
d d LIM MAT LC DCR d LIM MAT LC DCR
τ vant, see 6.1 where the adjustments factors are defined below
d
2 – Limit stress
Limit
Material / designation Value
stress
σ = min (σ ;0,5 σ ) or
a,b,c LIM y u
Metals, unwelded or well clear of heat affected zones
τ = min (τ ;0,5 τ )
LIM y u
σ or
LIM
σ = min (σ ;0,5 σ ) or
a,b,c LIM yw uw
τ Metals, within heat affected zones, in welded condition
LIM
τ = min (τ ;0,5 τ )
LIM yw uw
c
Wood or FRP as dictated by sense of applied stress (σ , σ , σ and τ ) as relevant
uc ut uf u
3 - Stress factor for material k
MAT
Metals with elongation at break ε ≥ 7 % k = 0,75
R MAT
d
k Metals with elongation at break ε < 7 % k = min (0,062 5 ε + 0,312 5;0,75)
MAT R MAT R
Wood and FRP k = 0,33
MAT
6 © ISO 2020 – All rights reserved

ISO 12215-10:2020(E)
Table 3 (continued)
e,
4 - Values of load case factor k ,
LC
Type of load: normal exceptional
Mast/rig Metal (1,11) (1,33)
Rig Pure fibre (1,30) (1,56)
Mast/rig FRP or wood (1,20) (1,44)
Step of mast/pillar, chainplate Metal 1,10 1,32
k
LC
Step of mast/pillar, chainplate FRP/Wood 1,05 1,26
f
Strapped FRP chainplates (UD straps only) 0,35 0,42
Connection of above to structure Metal 0,92 1,10
Connection of above to structure FRP/wood (bolts, screws, etc.) 0,88 1,05
f
Connection of above to structure FRP co-cured or glued 0,83 1,00
5 - Values of design category factor for rig k
DCR
Craft of design categories A and B 1,00
k
DCR
Craft of design categories C and D 1,25
a
Generally the heat affected zone is considered within 50 mm from welds.
b
For metals, τ = 0,58 σ often rounded to 0,6 as in EN 1993.
c
Bearing stress depends on material type and dimensions. Item 4 of Tables D.6 or D.7 gives recommended values.
(See References [13] and [15]).
d
The formula gives 0,75 for ε ≥ 7 % (e.g. main building metals and ductile cast iron) and 0,375 for ε < 7 % for
R R
lamellar graphite cast iron, with linear interpolation in between.
e
The design stresses correspond either to "normal" or "exceptional" cases in Table 7, the "exceptional" stresses
are 120 % the "normal "stresses i.e. the safety factor is 83 % of normal stresses. The “normal” design loads for
mast step/pillar or chainplates are 120 % of the ones for mast/rig, and the values of connection of mast step/
chainplate to the structure is again 120 % of the mast step/chainplate i.e. 144 % of mast/rig loads. k varies as
LC
the inverse of these ratios (see Table 4 for explanations).
f
The values for the UD of strapped chainplate are low to take into account stress raisers during the UD path
around the pin bushing, but this is not necessary for the co-curing/gluing of the whole chainplate, provided the
correct glue allowable shear stress is valid, see D.6.
NOTE  The design stresses in Table 3 and safety factors (S or S ) in Table 4 and loads for rig and mast elements
Fu Fy
are between brackets, for information only, as they are not covered by this document. The safety factor at ultimate
is stated (2,4) for metal rig but in practice it frequently varies between 2 and 3,5 for monohulls according to the
practice of the builder/designer and the type of craft racing/cruising. For light multihulls if may go down to 1,5
for the ones that “lift a hull” as this situation is non-frequent (exceptional) except for sheer sports multihulls. In
addition, the rig is frequently much stronger than stated to limit rig elongation for mast stability reasons, par-
ticularly for non-metal rigging system.
NOTE The lowering of k (or increase of safety factor S ) from rig load to mast step/chainplate, then
LC F
their connection to structure ensures that the mast step/chainplate connection will be stronger that the
mast compression/rig tension (i.e. the chainplate shall break after the rig), taking due consideration to the
uncertainties of calculation of the connection effective stresses.
6.2 Design load vs safety factor
The applicable limit stresses in the first row of Table 3 are multiplied by several factors like k
DCR,
design category factor, k , material factor, and k , load case factor. As many users or regulations
MAT LC
refer to safety factors, S , for comparison purposes Table 4 transforms the requirements of Tables 2
F
and 3 in terms of safety factors or equivalent. Taking R and R as respectively the yield and ultimate
y u
strength of a structural element, and F as the load in a rig element, it gives in the rows of Metal or
RIG
FRP respectively the ratio R /F , or R /F with, special consideration for metal whether σ > 0,5 σ
y RIG u RIG y u
or σ ≤ 0,5 σ .
y u
For simplicity, Table 4 only calculates in column 7 the safety factor at ultimate S = 1/(σ /σ ), and in
FU d u
column 8 the ratio S /S for “normal “load cases, showing the progression of the safety factors
FU FU RIG
ISO 12215-10:2020(E)
from mast/rig to connection to the structure. For “exceptional” load cases, the safety factor is multiplied
by 0,833 (i.e. divided by 1,2).
CAUTION — Table 4 shows the values for design categories A and B, with k = 1, for design
DCR
categories C and D with k = 1,25, the safety factor is multiplied by 1/1,25 = 0,8 i.e. reduced
DCR
by 20 %.
Table 4 — Values of the various safety factors computed from Table 3
1 2 3 4 5 6 7 8
σ = σ × k × k × k /
d LIM MAT LC DCR
σ
u
R rig
a u
Load case description σ /σ k k k σ /σ R
LIM u MAT DCR LC d u U ELEM
/F rig
Normal 1/(σ /σ ) /R
d u U RIG
Rig or mast load - Metal 0,50 0,75 1,0 1,11 0,42 (2,40) (1,00)
Rig or mast load - Pure fibre rig 1,00 0,33 1,0 1,30 0,43 (2,33) (0,97)
Mast load FRP - Mast 1,00 0,33 1,0 1,20 0,40 (2,53) (1,05)
Chainplate/mast step - AISI 316 0,42 0,75 1,0 1,10 0,35 2,87 1,19
Chainplate/mast step - ALU 5086 H111 0,42 0,75 1,0 1,10 0,34 2,91 1,21
Chainplate - FRP 1,00 0,33 1,0 1,05 0,35 2,89 1,20
Strapped FRP chainplates (UD straps only) 1,00 0,33 1,0 0,35 0.08 8,66 3,6
Connection to structure metal 0,42 0,75 1,0 0,92 0,29 3,48 1,45
Connection to structure FRP/wood - direct
1,00 0,33 1,0 0,88 0,29 3,46 1,44
stress
Connection to structure FRP co-cured /glued 1,00 0,33 1,0 0,83 0,27 3,65 1,52
a
Examples of calculation of values in column 2: AISI 316 plate σ /σ = min (220;0,5×520)/520 = 0,5; alumin-
LIM u
ium 5086 H 111 welded or not σ /σ = min(100;0,5×240)/240 = 0,423 0.
LIM u
7 Developed method — General assessments, design moment
7.1 General
7.1.1 General topics on rigging design
This document defines the required design loads on rig elements, but not their actual ultimate strength
or strain (elongation). This is because shrouds and stays are frequently over dimensioned due to
stiffness considerations to avoid mast buckling and limit the ‘fall-off’ of the mast to leeward. This is
particularly true for non-metal rig. In contrary, this document defines design loads for the connection of
the rig elements to their attachment or foundation (mast or pillar steps and rig attachment chainplates).
The loads on multihull rig elemen
...