kSIST FprEN ISO 11812:2019
(Main)Small craft - Watertight or quick draining recesses and cockpits (ISO/FDIS 11812:2019)
Small craft - Watertight or quick draining recesses and cockpits (ISO/FDIS 11812:2019)
This document specifies watertightness, draining time and sill heights requirements for watertight and quick-draining recesses and cockpits in small craft of up to 24 m load line length (see Reference [1]).
Recesses located in elevated parts of the craft are covered by this document.
This document does not specify requirements for the size, the shape and the location of recesses or cockpits. It only considers draining by gravity, and not by pumping or other methods.
It only considers normal operation of the craft, but unattended craft recess issues are out of scope.
This document does not guarantee that the water contained in a watertight or quick-draining recess or cockpit will not affect the stability and buoyancy of the craft, which are covered by ISO 12217 (all parts):2015.
Kleine Wasserfahrzeuge - Wasserdichte und schnell-lenzende Plichten (ISO/FDIS 11812:2019)
Petits navires - Cavités et cockpits étanches ou autovideurs (ISO/FDIS 11812:2019)
Le présent document spécifie les exigences relatives à l'étanchéité, au temps de vidange et à la hauteur des surbaux pour les cavités et les cockpits étanches et rapidement autovideurs dans les petits navires d'une longueur de ligne de charge inférieure ou égale à 24 m (voir la Référence [1]).
Les cavités situées dans les parties surélevées du bateau sont couvertes par ce document.
Ce document ne spécifie pas les exigences concernant la taille, la forme et l'emplacement des cavités ou des cockpits. Il ne prend en compte que la vidange par gravité, et non par pompage ou par d'autres méthodes.
Il ne prend en compte que le fonctionnement normal du bateau, mais les problèmes relatifs aux cavités des bateaux laissés sans surveillance sont en dehors du domaine d'application.
Ce document ne garantit pas que l'eau contenue dans une cavité étanche et rapidement autovideuse n'affectera pas la stabilité et la flottabilité du bateau, qui sont couvertes par l'ISO 12217 (toutes les parties):2015.
Mala plovila - Vodotesni prostori ter prostori in kabine s hitrim odvajanjem vode (ISO/FDIS 11812:2019)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN ISO 11812:2018
01-maj-2018
Mala plovila - Vodotesni prostori ter prostori in kabine s hitrim odvajanjem vode
(ISO/DIS 11812:2018)
Small craft - Watertight or quick draining recesses and cockpits (ISO/DIS 11812:2018)
Kleine Wasserfahrzeuge - Wasserdichte und schnell-lenzende Plichten (ISO/DIS
11812:2018)
Petits navires - Cavités et cockpits étanches ou autovideurs (ISO/DIS 11812:2018)
Ta slovenski standard je istoveten z: prEN ISO 11812
ICS:
47.080 ýROQL Small craft
oSIST prEN ISO 11812:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN ISO 11812:2018
oSIST prEN ISO 11812:2018
DRAFT INTERNATIONAL STANDARD
ISO/DIS 11812
ISO/TC 188 Secretariat: SIS
Voting begins on: Voting terminates on:
2018-02-21 2018-05-16
Small craft — Watertight or quick draining recesses and
cockpits
Petits navires — Cavités et cockpits étanches ou autovideurs
ICS: 47.080
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 11812:2018(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2018
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E) ISO/DIS 11812
Contents Page
Foreword . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 5
5 General requirements . 6
5.1 Loading and measurement conditions . 6
5.2 Requirements for watertight and “quick draining” recesses . 6
6 Watertightness requirements . 7
6.1 Watertightness requirements for “watertight” recesses . 7
6.2 Watertightness requirements for “quick draining” recesses . 7
7 Requirements for companionway sills . 7
7.1 Companionway sills concerned . 7
7.2 Recess with a “reduced risk of flooding” . 8
7.3 Sill height measurement . 8
7.4 Minimum companionway sill height for “quick draining” recesses. 9
8 Height of recess bottom above waterline for quick-draining recesses . 9
9 Quick-draining recesses – Single bottom recesses drainage . 9
9.1 Drainage general requirements . 9
9.2 Drain requirements . 10
9.2.1 Number and dimensions . 10
9.2.2 Special provisions. 10
9.2.3 Installation . 10
9.3 Drainage calculations requirements . 11
9.3.1 Drainage calculation principle and assessment methods . 11
9.3.2 Simplified drainage assessment method. 12
10 Quick-draining recesses – Multi-bottom recesses drainage . 13
10.1 Drainage general requirements . 13
10.2 Drainage requirements for foot basin . 13
11 Owner’s manual — Documentation . 15
Annex A (normative) Full calculation method for draining time . 16
A.1 Preliminary . 16
A.2 Procedure for calculation of a single bottom recess . 16
A.3 Equations and detail of calculation for a multiple bottom recess . 18
A.4 Dimensions of non-circular drains . 19
A.5 Principle of calculation where the drain diameters are different . 20
A.6 Determination of minor head loss coefficients K . 20
A.6.1 General . 20
Annex B (Informative) Examples of draining time calculation for single level and double level bottom
recesses . 24
© ISO 2018
B.1 Determination of the required drain diameter by direct calculation or simple method of
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
clause 10 . 24
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 B.2 Examples assessment of recesses with several bottom levels . 26
below or ISO’s member body in the country of the requester.
B.2.1 Two bottoms recess without foot basin . 26
ISO copyright office B.2.2 Closed recess with two bottom levels (see Figure B.3 a) . 26
CP 401 • Ch. de Blandonnet 8
B.2.3 Recess with two level bottom and aft part open (see Figure B.3 b) . 27
CH-1214 Vernier, Geneva, Switzerland
B.3 Recess with foot basin . 28
Tel. +41 22 749 01 11
B.3.1 Presentation . 28
Fax +41 22 749 09 47
copyright@iso.org
Annex C (normative) Watertightness tests . 30
www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
Contents Page
Foreword . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 5
5 General requirements . 6
5.1 Loading and measurement conditions . 6
5.2 Requirements for watertight and “quick draining” recesses . 6
6 Watertightness requirements . 7
6.1 Watertightness requirements for “watertight” recesses . 7
6.2 Watertightness requirements for “quick draining” recesses . 7
7 Requirements for companionway sills . 7
7.1 Companionway sills concerned . 7
7.2 Recess with a “reduced risk of flooding” . 8
7.3 Sill height measurement . 8
7.4 Minimum companionway sill height for “quick draining” recesses. 9
8 Height of recess bottom above waterline for quick-draining recesses . 9
9 Quick-draining recesses – Single bottom recesses drainage . 9
9.1 Drainage general requirements . 9
9.2 Drain requirements . 10
9.2.1 Number and dimensions . 10
9.2.2 Special provisions. 10
9.2.3 Installation . 10
9.3 Drainage calculations requirements . 11
9.3.1 Drainage calculation principle and assessment methods . 11
9.3.2 Simplified drainage assessment method. 12
10 Quick-draining recesses – Multi-bottom recesses drainage . 13
10.1 Drainage general requirements . 13
10.2 Drainage requirements for foot basin . 13
11 Owner’s manual — Documentation . 15
Annex A (normative) Full calculation method for draining time . 16
A.1 Preliminary . 16
A.2 Procedure for calculation of a single bottom recess . 16
A.3 Equations and detail of calculation for a multiple bottom recess . 18
A.4 Dimensions of non-circular drains . 19
A.5 Principle of calculation where the drain diameters are different . 20
A.6 Determination of minor head loss coefficients K . 20
A.6.1 General . 20
Annex B (Informative) Examples of draining time calculation for single level and double level bottom
recesses . 24
B.1 Determination of the required drain diameter by direct calculation or simple method of
clause 10 . 24
B.2 Examples assessment of recesses with several bottom levels . 26
B.2.1 Two bottoms recess without foot basin . 26
B.2.2 Closed recess with two bottom levels (see Figure B.3 a) . 26
B.2.3 Recess with two level bottom and aft part open (see Figure B.3 b) . 27
B.3 Recess with foot basin . 28
B.3.1 Presentation . 28
Annex C (normative) Watertightness tests . 30
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
C.1 General . 30
C.2 Watertightness tests . 30
C.2.1 Determination of degrees of watertightness and weathertigntness . 30
C.2.2 Test for “spraytitght” level . 31
Annex D (Informative) Technical background . 33
D.1 Calculations for a single bottom recess . 33
D.1.1 Calculation for a "perfect" fluid i.e. no viscosity and no head loss . 34
D.2 Calculation with "real" fluids and head losses . 35
D.2.1 General . 35
D.3 Calculation of the draining time of a two bottoms recess with "real" fluids and head losses . 36
D.3.1 General . 36
D.3.2 Major (frictional) head losses – For information only . 37
D.3.3 Minor head losses . 37
D.4 Water flow in a foot basin . 37
Annex E (Informative) Examples of “quick draining” recesses . 38
Bibliography . 40
iv © ISO 2018 – All rights reserved
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO's adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 188, Small craft.
This second edition cancels and replaces the first edition (ISO 11812:2003), of which it constitutes a
major revision. In this revision, based on 10 years of application, the main changes are:
introduction of the concept of aft open cockpits;
clarification of requirements;
systematic usage of the general term "recess" instead of "cockpit";
clarification of requirements on engine ventilation ducts in recesses;
implementation of multi bottom recesses or recesses with a foot-well in the main core of the
standard;
deletion of "major head losses" (friction in drain pipes) as their effect was very small, but this made
the calculation much more complex;
improved data for "minor head losses" (local losses) to correspond to common practice;
reduction of remaining water in the recess from 0,1 m to 0,05 m.
oSIST prEN ISO 11812:2018
oSIST prEN ISO 11812:2018
DRAFT INTERNATIONAL STANDARD ISO/DIS 11812:2018(E)
Small craft — Watertight or quick draining recesses and cockpits
1 Scope
This International Standard specifies requirements for recesses and cockpits in terms of watertightness,
draining time, and sills in way of cockpit companionway doors or hatches, for small craft up to 24 m
length of hull. Recesses located in elevated part of the craft shall be considered by the scope of this
standard. This standard only considers normal operation of craft, as defined in ISO 8666.
Unattended craft recess issues are considered out of the scope of this standard;
It does not set requirements for the size and the shape of a recess or cockpit, or where it shall be used. It
only considers draining by gravity, and not by pumping or other methods.
This international standard does not guarantee that the water contained in a watertight or quick draining
recess or cockpit will not harm stability and floatability, which are covered by ISO 12217.
NOTE 1 The term "quick-draining" has been chosen in differentiation from the common understanding of "self-
draining" where water may be drained overboard in certain conditions, but without specified draining speed, height
of bottom or sill, etc.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 8666— Small craft — Principal data.
ISO 9093-1, Small craft — Seacocks and through-hull fittings — Part 1: Metallic.
ISO 9093-2 Small craft — Seacocks and through-hull fittings — Part 2: Non-metallic.
ISO 12216 Small craft —- Windows, portlights, hatches, deadlights and doors — Strength and tightness
requirements.
ISO 12217 (all parts), Small craft — Stability and buoyancy assessment and categorization.
ISO 12215- Parts 5& 7, Small craft — Stability and buoyancy assessment and categorization.
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
3.1
design category
description of the sea and wind conditions for which a craft is assessed to be suitable (see ISO 8666)
NOTE 1 to entry: The definitions of these design categories align with those used in the Recreational Craft
Directive of the European Union, EU Directive 2013/53/EC.
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
3.2
sailing craft
craft for which the primary means of propulsion is by wind power, having reference sail area, as defined
2/3
in ISO 12217: A ≥ 0,07(m ) where m is the mass of the craft in the maximum load condition,
S LDC LDC
expressed in kilograms.
3.3
non-sailing craft
craft not designed to use sails as primary means of propulsion
3.4
heeled waterline
the level of the water on the hull in the fully loaded, ready-for-use condition according to ISO 8666 when
the craft is inclined to:
—an angle of 7° for motor boats and sailing multihulls; or
—30° or immersion of the sheerline, whichever occurs first, for monohull sailing boats.
3.5
recess
volume open to the air that may retain water within the range of loading conditions and corresponding
trims
EXAMPLE Cockpits, wells, open volumes or areas bounded by bulwarks or coamings.
NOTE 1 to entry: Cabins, shelters or lockers provided with closures according to the requirements of ISO 12216
are not recesses.
NOTE 2 to entry: A recess can be composed of several recesses connected together
3.6
cockpit
recess intended for the accommodation of people
3.7
watertight recess
recess which satisfies the requirements of this document for watertightness requirements and sill height,
but not those for drainage
3.8
quick-draining recess
Recess with characteristics and draining capacity which fulfil all the requirements of this International
Standard for one or several design categories
NOTE 1 to entry: According to its characteristics, a recess may be considered quick-draining for one design
category, but not for a higher category.
3.9
recess open to the sea
recess where its aft boundary is open to the outside of the craft with a recess retention height equal to
zero according to 3.21.
NOTE 1 to entry Figure 1 c) gives an example of a recess open to the sea .
2 © ISO 2018 – All rights reserved
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
3.10
recess bottom
the lowest surface of the recess sole where water collects before being drained. The recess bottom may
have several levels
NOTE 1 to entry Devices raising the sole level(s) above the rigid bottom of the cockpit sole, e.g. grating, stands,
bridge decks, are not considered as part of the recess bottom.
3.11
recess bottom height
H
B
height of the recess bottom above waterline, the craft being upright, at rest and fully loaded
3.12
minimum recess bottom height
H
B min
Minimum value of H required by this document
B
3.13
single bottom recess
recess where the bottom has only one plane
3.14
multi-bottoms recess
recess where the bottom has more than one plane
3.15
bridge deck
area in the proximity of the companionway opening and above recess bottom, on which people normally
step before entering the accommodation
3.16
interior
Inside part of the craft watertight envelope.
3.17
watertightness degree
capacity of an appliance or fitting to resist ingress of water, according to the conditions of exposure to
water.
Definitions of the degrees of watertightness
Table 1 —
Degree of watertightness: Definition
1 (waterproof) Constructed to withstand continuous immersion
Protection against effects of continuous immersion of water
2 (watertight) Constructed to prevent ingress of water when tested according to D.2
Protection against effects of temporary immersion water
3 (weathertight) Constructed to minimize seepage when tested according to D.3
Protection against splashing water
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
4 (spraytight) Protection against waterdrops falling at an angle of up to 15° from the
vetrtical
3.18
downflooding opening
opening in the hull or deck (including the edge of a recess) that might admit water into the interior or
bilge of a craft, or a recess, apart from those excluded by ISO 12217
3.19
appliance
device made of a plate and its associated framing, opening and fixture systems, if relevant, used to cover
an opening in the hull, deck or superstructure of a craft; that may be fixed or opening (detachable, hinged,
sliding, folding, etc.)
EXAMPLE Windows, portlights, hatches, deadlights, doors, sliding appliances, escape hatches,
washboard.
3.20
fixed appliance
Non-opening appliance
3.21
opening appliance
appliance that can be opened
3.22
recess retention height
hC
height of water in a recess, when the craft is upright and at design trim, at which 20% of the uppermost
periphery of the surrounding coaming (measured in a horizontal plane parallel to waterline) would be
covered by water, assuming that all gates, doors or drainage openings are considered to be sealed, unless
the drainage area is greater than 0,005L B
H H
Note 1 to entry: The design trim is in mLDC condition as defined in ISO 8666
3.23
drain
outlet of the recess enabling water contained to be discharged outboard by gravity
NOTE 1 to entry Examples of drains: a pipe discharging overboard above or below waterline; a part of the recess
allowing direct discharge overboard; scuppers and freeing port.
3.24
companionway
opening intended for crew access to the craft’s interior and fitted with an opening appliance
Note 1 to entry: the opening appliance can be a door, a hatch, vertical, horizontal etc.
Note 2 to entry: There may be several companionways.
3.25
sill
barrier above which water in the recess may enter companionway openings and downflood the craft
4 © ISO 2018 – All rights reserved
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
Note 1 to entry: The lids to cockpit lockers or any opening other than the companionway opening, and leading
into non-quick-draining parts of the boat are not considered to be sills if the closing appliance covering them fulfils
the watertightness requirements of clause 6.
3.26
fixed sill
sill being a fixed, integral and permanent part of the recess
3.27
semi-fixed sill
any closing appliance movable but permanently attached to the boat which, when in place, constitutes a
sill higher than the fixed sill
EXAMPLE Sliding or hinged doors, hatches, sliding sills, but excluding washboards.
NOTE 1 to ENTRY: A lanyard is not regarded as a permanent attachment.
3.28
washboards
closing appliance for companionway opening made of several mobile boards sliding in a rabbet that,
when closed, are stacked one on top of each other, and located above the required sill height hs min
Note 1 to entry: This is a frequent device on sailing monohulls: boards are added as the weather worsens
3.29
sill height
h
s
vertical distance between the adjacent recess bottom and the top of the sill
3.30
minimum sill height
h
s min
minimum sill height required by this document
3.31
recess volume
V
C
volume of water that can be contained in a recess before discharge
Note 1 to entry: the volume shall be the maximum volume, considering any possible combination of outside doors,
movable coamings, etc. The volume is measured from the recess bottom up hC, assuming that all closing appliances
and drains are closed
3.32
foot-basin
specific recess located between recess and companionway opening, having a lower bottom than the
surrounding recess and covered with a grating
3.33
readily accessible
capable of being reached quickly and safely for effective use under emergency conditions without the use
of tools
4 Symbols
Table 1 summarizes the main symbols used in this document.
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
Table 2 — Table of symbols used in the main core
Symbol Meaning Unit
B Beam of hull as defined by ISO 8666 m
H
F Freeboard amidships as defined by ISO 8666 m
M
hC Recess retention height m
h Sill height m
S
hS min Required minimum sill height m
H Recess bottom height above waterline m
B
HB min Minimum recess bottom height above waterline m
k Recess volume coefficient -
C
LH Length of hull as defined by ISO 8666 m
V Recess volume m
C
tmax Maximum allowable draining time min
t Reference draining time min
ref
di Drain diameter in millimetres mm
NOTE: Heights measured above the recess bottom have symbols beginning with h, whereas heights
measured above waterline have symbols beginning with H.
5 General requirements
5.1 Loading and measurement conditions
Unless otherwise specifically stated in the text:
− the craft is in maximum load condition m as defined in ISO 8666;
LDC
− lengths and heights are all measured in m, areas in m², volumes in m3, time in minutes and/or
seconds;
− measurements or calculations shall be made with the craft upright and at rest in calm water.
5.2 Requirements for watertight and “quick draining” recesses
Table 2 summarizes relevant clauses to address requirements for watertight and “quick draining”
recesses.
Table 3 —Relevant clauses for recesses compliance
Requirements: Watertight recess “Quick draining” recess
Watertightness Clause 6 Clause 6
Companionway Sill None Clause 7
Height of recess bottom None Clause 8
Drainage None Clause 9 and 10
Strength of appliances ISO 12216 ISO 12216
6 © ISO 2018 – All rights reserved
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
6 Watertightness requirements
6.1 Watertightness requirements for “watertight” recesses
In watertight recesses, all surfaces and applicances shall have a watertightness degree 1 up to h , or h
c s min
whichever is greater.
6.2 Watertightness requirements for “quick draining” recesses
All surfaces shall have a watertightness degree 1.
Fixed (i.e. non-opening) appliances shall have a watertightness degree 2.
Watertightness degrees of opening appliances covering downflooding openings and installed on the
surfaces of the quick-draining recess shall comply with the requirements of Table 4.
Table 4 —Watertightness degrees of opening appliances
a
Degree of watertightness
Location of opening appliances in the recess
Opening appliance on bottom and sides up to hs min 2
Opening appliance between hs min and 2 hs min 3
Opening appliance above 2 h 4
s min
NOTE 1 On engine ventilation ducts, the watertightness assessment using test of Annex C may be performed using the total
arrangement of exterior grid and internal ducts or swan’s neck of the appliance.
NOTE 2 Additional requirements may be set up by other International Standards, such as ISO 12217
a
h is defined in Table 5, the local sill height and hs min being measured as required by Table 5
s min
Opening appliances covering downflooding openings and installed on the surfaces of the quick-draining
recess shall be secured in the closed position by a manually operated mechanical positive device.
7 Requirements for companionway sills
7.1 Companionway sills concerned
The sills concerned are the ones of the companionway and located inside the limits of the recess
concerned plus an area 0,6 m wide extending horizontally all around the recess (see Figure 2)
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
Key
1 sill height
2 front companionway door on bulkhead
3 aft companionway hatch on deck
Figure 1 — Sills considered and sill height measurement
In Figure 2, as the front and aft companionway are within 0,6 m from recess edge, (hatched area), the sill
requirements (height, watertighness, etc.) apply.
7.2 Recess with a “reduced risk of flooding”
A recess with "Low risk of flooding " is a protected recess fitted on craft which comply with the following
criterions:
- the boat is fully enclosed type;
- the recess is a quick draining open to the sea recess as defined in this document;
- all of the recess shall be located aft of the mid hull length of the craft;
- companionway is installed on the rear face of a superstructure with a closure complying with clause
7.4;
- it has the lowest point of the companionway opening higher than [(Lh /17) + h ],
Smin
For this specific “Low risk of flooding” recess, a sill is not required.
7.3 Sill height measurement
The sill height is the lowest height of the companionway, as defined in 3.22.
The sill height shall be measured vertically from the adjacent closest point of the recess bottom to the
lowest point of the upper sill edge, (see Figure 2).
8 © ISO 2018 – All rights reserved
0,6 m
0,6 m
0,6 m
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
In a multi bottoms recess, the recess adjacent to the sill (usually a foot basin) where the sill height is
measured shall have minimum dimensions (width, length, and location) of Table 11. Otherwise, the next
upper recess complying with minimum dimension shall be used for measurement.
If a recess is fitted with a foot-basin complying with foot-basin requirements of Clause 9.5, the sill height
shall be measured from the foot-basin bottom; otherwise, the sill height shall be measured from the
closest recess bottom
7.4 Minimum companionway sill height for “quick draining” recesses
Table 5 defines the requirements regarding minimum companionway sill height for “quick draining”
recesses
Table 5 —Minimum companionway sill height h for “quick draining” recesses
S min
Sailing monohulls Non-sailing craft and sailing multihulls
Design
top of sill top of sill
Category
h h
s min s min
A 0,3 0,2
B 0,25 0,15
C 0,15 0,1
D 0,05 0,05
In case of semi-fixed sill, permanent part height shall be ≥ (h / 2)
smin
NOTE The above requirements may be raised by other International standards such as ISO 12217
8 Height of recess bottom above waterline for quick-draining recesses
Table 6 defines the requirements regarding quick-draining recess bottom height H above waterline.
B min
For a single bottom recess, H is measured at the centre of surface of the bottom.
B
For a multi- bottom recess, H is measured at the centre of surface of the lowest bottom.
B
Table 6 — Minimum height H of the recess bottom above waterline
B min
Design category Height H (m)
B min
A 0,15
B 0,1
C 0,075
D 0,05
NOTE Greater heights than these minimum values may be required to fulfil the maximum
acceptable draining time according to Clause 9 and 10
9 Quick-draining recesses – Single bottom recesses drainage
9.1 Drainage general requirements
Draining shall only be by gravity.
If there are mobile parts allowing opening in the recess sides, the requirement shall be verified in the
worst configuration, e.g. if there are doors, they are considered closed.
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
When the craft is upright at least 98 % of the recess volume shall drain.
Both to port and starboard heel, drainage shall be provided for at least 90 % of V when the crat is at
C
heeled waterline, as defined in this standard.
Based on one single level, linked recesses shall be treated as being separate if total cross section area <
120% of the minimum drainage area of the total volume of all recesses.
9.2 Drain requirements
9.2.1 Number and dimensions
A quick-draining recess shall have at least two drains, one port and one starboard, unless one opening
enables drainage when the craft is at heeled waterline according to clause 9.1 to both port and starboard.
Drain with circular cross section shall have an internal diameter of at least 25mm.
Drain with other cross-sectional shapes shall have an internal cross-sectional area of at least 500mm2,
and an internal minimum dimension of 20mm.
9.2.2 Special provisions
In case of protected grids or systems preventing loose objects from falling into the draining system, one
shall be aware that a grid of small holes is more prone to be clogged than the drain itself. If the minimum
passage dimension inside any part of these devices has at least a section of 125 mm² (or a diameter of 12
mm), and the total entry cross-section is at least the 1,5 times the internal cross-section of the drain, the
simple draining time assessment method of Clause 9.3.2 may be used, otherwise the draining time
assessment shall be performed according to Annex A, and unless specifically documented, using the
minor losses coefficient of A.6 for protective grid.
In case of centreboard housings and other types of aperture; they may be used as drains if they are
designed for this purpose and fulfil the other requirements of clause 9.
9.2.3 Installation
When the craft is in mLDC condition, the drain outlet running through the hull shall either be located:
- above the waterline or;
- below waterline and be fitted with seacocks unless the drain outlet is an integral part of the hull
extending from the outlet up to at least 0,75 H above waterline.
Bmin
Figure 3 shows a drain outlet integral with the hull.
All the drain piping system shall have a watertightness degree 1.
Drain piping shall be protected against damage from loose objects stowed in the craft and against being
kicked or stepped on.
Drain piping installed in the engine room shall be able to withstand 70°C or be insulated from the heat.
Drain piping shall not trap water and shall only be used for recess drainage. This requirement does not
apply to drains fitted in centreboard housing or outboard wells and trunks.
Seacocks, through-hull fittings, and associated components shall comply with ISO 9093–1 or ISO 9093–2.
10 © ISO 2018 – All rights reserved
oSIST prEN ISO 11812:2018
ISO/DIS 11812:2018(E)
Key
1 Waterline
2 Top of integral penetration above 0,75 HB min: no seacock required
3 In this area, the drain is integral with the hull shell
Figure 2 — Drain outlet being an integral part of the hull
9.3 Drainage calculations requirements
9.3.1 Drainage calculation principle and assessment methods
The drainage calculation principle of this standard for “quick draining” recesses is based on a maximum
draining time approach.
The draining time is the one elapsed to empty the recess between the retention height h and 0,05 m of
C
remaining water height.
The water height shall be measured above the centre of the bottom surface of the recess. Due to the recess
filling, the trim angle may change between the beginning and the end of the measurement, and therefore
the contained height shall be measured above the centre of the recess bottom surface.
NOTE According to this standard, the recess bottom may be above waterline when the recess is empty and below
with a full recess and in calculations one shall consider the longer draining time.
To define the size of single bottom recess drains according to the requirements of this standard for “quick
draining” recesses, 3 methods are provided:
- simplified method as defined in Clause 9.3.2 which provide conservative results;
- enhanced method as defined in Annex A which give improved results;
- test method in accordance with maximum draining time requirements of Table 8 and Figure 4.
The draining time shall be assessed, by test or by calculation, with every closing appliance closed.
NOTE If the drain time is tested, it may be useful to indicate the point located 0,05 m above the centre of the
recess bottom by a tape mark.
If the draining section of the volume of the recess is superior or equal to 0,05 V , the draining section is
C
considered large enough to fulfil the requirements for this volume and do not require a draining time
assessment.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.