Ship Windows
Ship Windows
Ship Windows
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UDC 629.12.011.83
Specification for
Ships’ windows
BRITISH STANDARD MARINE SERIES
BS MA
25:1973
Incorporating
Amendment No. 1
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Contents
Page
Foreword iii
1 General 1
1.1 Scope 1
1.2 Definitions 1
1.3 Conformity with law or regulation 2
2 Materials 2
2.1 General 2
2.2 Schedule of materials 3
3 Glasses for ships’ windows 3
3.1 General 3
3.2 Dimensions of toughened safety glasses 3
3.3 Examination and testing of toughened glasses 5
3.4 Marking 6
4 Dimensions and tolerances for ships’ windows 7
5 Design and construction 10
5.1 General 10
5.2 Windows for sea-going ships 10
5.3 Windows for ships in sheltered or inland waters 10
5.4 Hinge pins and window fasteners 11
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6 Glazing 11
6.1 General 11
6.2 Wheelhouse windows 12
6.3 Glazing strips, glazing screws and fixing bolts 12
7 Installation and testing 12
7.1 Installation 12
7.2 Testing 13
7.3 Inspection 13
7.4 Testing facilities 13
8 Identification 13
Appendix A Examination of toughened safety glass using polarized light 14
Appendix B Suitable apparatus for load stamp test of toughened safety glass 15
Appendix C Timber for ships’ window frames 15
Appendix D Windows for ships operating in sheltered waters 16
Appendix E Method for calculating the thickness of toughened safety glass
using design pressure head formulae 16
Figure 1 — Edge of the glass 5
Figure 2 — Rectangular windows 7
Figure 3 — Category 1 and Category 2 windows 9
Figure 4 — Profile showing tiers, datum deck and weather deck 9
Figure 5 — Polariscope for examining for standard of toughening of glass 14
Figure 6 — Apparatus for load stamp test of toughened glass 15
Figure 7 — Curve for determination of factor ¶ based on window size ratio 18
Table 2 — Tolerance on thickness of glass 4
Table 3 — Tolerance on flatness and parallelism of glass 4
Table 4 — Dimensions of arris for edge of glasses 4
Table 5 — Proof loading for load stamp test 5
Table 6 — Dimensions of ships’ windows 8
Table 7 — Dimensions and number of window hinge pins and fasteners 11
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Page
Table 8 — Glazing dimensions for wheelhouse windows 12
Table 9 — Dimensions for glazing strips, glazing screws and fixing bolts 12
Table 10 — Maximum allowable pressure head on toughened safety glass
for standard sizes of ships’ windows 17
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BS MA 25:1973
Foreword
This British Standard has been prepared under the authority of the Shipbuilding
and Marine Industry Standards Committee and provides requirements for the
design (including dimensions), construction, glazing, testing and installation of
ships’ windows.
The standard is based on the experience of glass and window manufacturers and
shipbuilders, and of Authorities who apply to ships the provisions of the
International Convention for the Safety of Life at Sea, (1960) and of the
International Convention respecting Load Lines, (1930 and 1966) and follows the
standard being prepared by Technical Committee ISO/TC 8 — Shipbuilding, of
the International Organisation for Standardization (ISO).
Consideration has also been given to the safety of passengers and crew and also
to the safety of the ship, having regard to the safety convention and load line
convention, both of which require that openings in ships’ hulls and ships’
superstructure shall be efficiently protected.
The design and scantlings of ships’ windows in this standard will normally be
applicable to ships engaged on sea voyages, but in the case of ships on restricted
services such modifications of this standard as appears reasonable may be
allowed, having regard to the services of these ships.
The dimensions of ships’ windows specified have been adopted from the
future ISO standard being prepared by the Technical Committee
ISO/TC 8 — Shipbuilding, of the International Organisation for Standardization,
(in which the United Kingdom has taken an active part), to facilitate the repair
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of ships’ windows.
The standard also includes requirements for the testing of glasses for ships’
windows, based on ISO 614. Details of the apparatus to be used for the testing of
glasses is given in the Appendices.
The requirements of this British Standard appertaining to toughened safety
glasses for ships’ windows supersede those specified in BS 3925:1965, which will
accordingly be withdrawn.
It is not the purpose of this standard to specify precautions, such as the provision
of shutters, that may have to be taken in certain weather conditions for the
protection of glasses in ships’ windows.
A further related standard in this Marine Series is BS MA . . . . , Specification for
side scuttles for ships, (revision of BS 3024), in course of preparation.
This standard makes reference to the following British Standards:
BS 309, Whiteheart malleable iron castings.
BS 310, Blackheart malleable iron castings.
BS 952, Classification of glass for glazing and terminology for work on glass.
BS 970, Wrought steels in the form of blooms, billets, bars and forgings.
BS 1400, Copper alloy ingots and copper and copper alloy castings.
BS 1490, Aluminium and aluminium alloy ingots and castings.
BS 1631, See BS 3100.
BS 1632, See BS 3100.
BS 2872, Copper and copper alloys. Forging stock and forgings.
BS 2874, Copper and copper alloys. Rods and sections (other than forging stock).
BS 3100, Steel castings for general engineering purposes.
BS 1631, Austenitic chromium-nickel steel castings for resistance to corrosion.
BS 1632, Austenitic chromium-nickel-molybdenum steel castings for resistance to
corrosion.
BS 3643, ISO metric screw threads — Part 1 Thread data and standard
thread series — Part 2 Limits and tolerances for coarse pitch series threads.
BS 4360, Weldable structural steels.
A British Standard does not purport to include all the necessary provisions of a
contract. Users of British Standards are responsible for their correct application.
Summary of pages
This document comprises a front cover, an inside front cover, pages i to iv,
pages 1 to 18, an inside back cover and a back cover.
This standard has been updated (see copyright date) and may have had
amendments incorporated. This will be indicated in the amendment table on the
inside front cover.
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BS MA 25:1973
NOTE 1 Users of this British Standard: Marine Series should note that while observing the requirements of the Standard they
should at the same time ensure compliance with such statutory requirements, rules and regulations as may be applicable to the
individual ship concerned. (See also 1.3)
NOTE 2 Attention is drawn to the fact that some ships’ windows are subject to letters patent.
1 General
1.1 Scope
This British Standard specifies requirements for the design (including dimensions), construction,
scantlings, glazing, testing and installation of non-opening and opening type windows for ships. It also
specifies the thicknesses of toughened safety glasses for ships’ windows located in the respective tier
positions in both passenger and non-passenger ships.
1.2 Definitions
For the purposes of this British Standard the following definitions apply.
1.2.1
passenger ship
a ship carrying more than 12 passengers
1.2.2
bulkhead deck
the uppermost deck to which the transverse watertight bulkheads extend. Where used herein refers to
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1.2.7
safety glass (General definition.)
a glass which, if fractured, gives fragments which are less liable to cause severe cuts than fragments
of ordinary glass
1.2.8
toughened safety glass
glass which has been converted to safety glass by subjection to a process of heating and rapid cooling so
that if fractured it disintegrates into small pieces and, in addition, its liability to fracture under the action
of external forces or changes of temperature is greatly reduced
1.2.9
laminated toughened safety glass
a product consisting of two or more pieces of toughened safety glass firmly united to and alternating with
one or more pieces of reinforcing material known as “interlayer” or “interleaf”. The adhesion should be such
that fracture will not cause the glass to separate from the interlayer to any substantial extent and that the
glass will not break into large fragments capable of causing severe injury
1.2.10
batch
a quantity of glasses of the same size and thickness and which show a similar strain pattern when viewed
by polarized light
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2 Materials
2.1 General
The materials used in the construction of window scantlings to this standard shall comply with those
specified in 2.2 as regards chemical composition and mechanical properties, as a minimum requirement.
The mechanical testing of all materials specified in 2.2 shall be carried out in accordance with the
mechanical test requirements of the appropriate British Standard listed in the schedule.
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BS MA 25:1973
HE9
HE30
Naval BS 1400
die castings (DCB1)
(DCB3)
Wrought BS 970
corrosion 321S12
resistant 34S17
316S16
Cast BS 1631
corrosion BS 1632
resistant
3.2.1 Thickness of glasses. The thickness of glasses for ships’ windows, according to the nominal window
dimension and location of the tier, shall be calculated from the formula given in Appendix E, which takes
into account the ship’s length, breadth, freeboard, block coefficient and breadth of deck houses.
3.2.1.1 When obscured glass is fixed with the obscured surface facing inwards, one thickness greater than
that calculated shall be used.
3.2.1.2 When obscured glasses are used with the obscured surface on the outside, the calculated thickness
is acceptable, providing the depth of sandblast treatment does not exceed 0.125 mm. It is preferable that
the obscuring treatment should be applied before the glass is toughened.
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BS MA 25:1973
3.2.1.3 Where windows of the 2nd tier and tiers above are situated in positions at a distance of at least 4 %
of the breadth of the ship from the ship’s side or 1.5 m whichever is the greater, or positioned behind
screens, the glass may be reduced by one thickness.
3.2.2 Tolerance on thickness. The tolerance on thickness shall be according to the values given
in Table 2.
Table 2 — Tolerance on thickness
of glass
Nominal thickness of glass Tolerance
mm mm
10 ± 0.3
12 ± 0.3
15 ± 0.5
19 ± 1.0
25 ± 1.0
3.2.3 Tolerance on flatness and parallelism of glass thickness. The tolerance on flatness and
parallelism of glasses shall be as specified in Table 3.
Table 3 — Tolerance on flatness and parallelism of glass
Nominal thickness of glass (t) mm 10, 12, 15, 19, 25
Tolerance on
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parallelism (p)
(mm/1 000 mm) 0.2
Tolerance on
flatness (f)
(mm/1 000 mm) 2.0
3.2.4 Edges of toughened safety glasses. All edges shall be arrissed and finished to remove sharpness
and roughness. Edges of glasses of nominal thickness over 12 mm should be ground flat and arrissed or
finished by some other such process providing that the finished dimension conforms to the dimensional
tolerances specified in Table 6. The width (s) and depth (y) of the arris should not exceed the dimensions
in Table 4.
The arrissing should be carried out before toughening the glass.
Table 4 — Dimensions of arris for
edge of glasses
Nominal thickness Maximum Minimum
of glass, t width, s depth, y
mm mm mm
10 1.4 1.0
12
15
2.0 1.4
19
25
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BS MA 25:1973
3.3.2 Strength test. Manufacturers shall guarantee that glasses for windows for ships, purporting to
comply with this specification will pass the load stamp test and acceptance conditions described in 3.3.4
to 3.3.6.
In the event of a purchaser requiring tests to be made on any consignment of glasses, the sampling
procedure described in 3.3.3 shall be adopted.
A suitable apparatus for carrying out the load stamp test is described in Appendix B.
3.3.3 Sampling of glasses. Each batch of glasses shall be tested separately. Where a batch consists
of 4 glasses or less, each of the glasses shall be tested. Where a batch consists of more than 4 glasses, the
test shall be carried out on a random sample of 4 glasses, or on 2 % of the batch, whichever figure is the
greater.
3.3.4 Proof loading. Each glass to be tested shall be subjected to the proof loading specified in Table 5,
according to the nominal thickness of the glass.
Table 5 — Proof loading for load stamp test
Glass thickness Proof loading
mm mm N N
10 9.7–10.3 11 000 10 200
12 11.7–12.3 16 500 15 500
15 14.5–15.5 25 500 24 000
19 18.0–20.0 36 800 33 400
25 24.0–2.60 — 53 000
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BS MA 25:1973
3.4 Marking
3.4.1 The following particulars shall be indelibly and distinctly marked by the manufacturer on each piece
of toughened glass intended for glazing a ship’s window in such a position that the markings will be visible
when the glass is positioned in the glassholder.
All individual markings shall be grouped together, preferably in the bottom right hand or left hand corner
of the glass.
1) The name, registered trade mark or licence number of the manufacturer.
2) The number of this British Standard, i.e. BS MA 25.
NOTE This British Standard provides for a product which covers personal safety. Manufacturers and purchasers are urged to
make use of the certification scheme whereby the product may bear the registered certification mark of BSI. For further
information see the in side back cover of this standard.
3) A single triangle, inverted to indicate that the glass is clear toughened safety glass, or a double
triangle for obscured and other non-transparent toughened safety glass.
The nominal thickness of the glass shall also be indicated within the triangle.
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4 Dimensions and tolerances for ships’ windows
7
BS MA 25:1973
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Table 6 — Dimensions of ships’ windows
8
BS MA 25:1973
Nominal Window Glass Glass recess
dimension of
Clear light size W1 h1
window
N W h R r max. min. max. min. R1 r1 W2 h2 R2 r2
mm × mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm
300 × 425 300 425 425 318 314 443 439 433 321 446 435
355 × 500 355 500 500 50 373 369 518 514 508 58 376 521 510 60
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400 × 560 400 560 560 418 414 578 574 568 421 581 570
450 × 630 450 630 630 468 464 648 644 638 471 651 640
500 × 710 500 710 710 518 514 728 724 718 521 731 720
560 × 800 560 800 800 100 578 574 818 814 808 108 581 821 810 110
900 × 630 900 630 2 500 918 914 648 644 2 508 921 651 2 510
1 000 × 710 1 000 710 2 750 1 018 1 014 728 724 2 758 1 021 731 2 760
1 100 × 800 1 100 800 3 000 1 118 1 114 818 814 3 008 1 121 821 3 010
NOTE Glass: W1 = W + 2(8 ± 1) mm Glass recess: W2 = W1 max. + 3 mm
h1 = h + 2(8 ± 1) mm h2 = h1 max. + 3 mm
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Category 1 requirements apply when dimension X is less than 4 % of the breadth (B) of the ship
or 1.5 metres whichever is the greater (see 5.1).
Category 2 requirements apply when dimension X is greater than 4 % of the breadth (B) of the ship or more
than 1.5 metres.
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BS MA 25:1973
5.2.3 Category 1, opening windows (sliding). For design purposes horizontal and vertical sliding
windows are assumed to be in the closed position during inclement weather and in the closed position
clamped on all edges for weatherproofing. Therefore the same thickness of glass as for fixed windows is
acceptable.
5.2.4 Category 2, opening windows. The minimum nominal thickness for Category 2 windows shall be
one glass thickness less than for Category 1 windows situated in the same tier, subject to a minimum
thickness of 10 mm.
5.2.5 Wheelhouse windows. The glass thickness for wheelhouse windows facing forward shall be in
accordance with that specified for Category 1 windows in 5.2.2.2. Side windows in wheelhouses shall be
regarded as Category 2 windows.
Where electrically heated laminated glass is installed the glass thickness shall be one glass thickness
greater than for Category 1 windows situated in the same tier, or alternatively of equal thickness,
laminated with a thinner glass of 6 mm thickness, the thinner glass being on the outer surface.
Wheelhouse windows consisting of multipane units shall be made up of single pane units of sizes in
accordance with those specified in Table 6. The astragals and mullions shall be an integral part of the
window frame rather than part of the ship structure.
5.2.6 Windows other than those covered in 5.2.1 to 5.2.4
5.2.6.1 For windows of cabins or public rooms protected by side screens, glass thicknesses may be one glass
thickness less than that specified for Category 2 windows in the same tier, subject to a minimum thickness
of 10 mm.
5.2.6.2 For windows in internal positions, e.g. glass screens in public rooms, the minimum nominal
thickness of glass shall be 6 mm provided that the window is completely framed and the area does not
exceed 0.75 m2; otherwise the minimum nominal thicknesses shall be 10 mm.
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BS MA 25:1973
mm × mm mm mm mm
6 Glazing
6.1 General
When glazing it is essential to position the glass in the frame so that:
1) the glass is centralized in the frame and suitably edge protected;
2) there is clearance all round the edges of the glass;
3) glass to metal contact is avoided.
To achieve these requirements the toughened safety glass shall be glazed, using continuous resilient
glazing strips around the edges of the glass and between the surfaces of the glass and the rebate depth and
the bead. Mastic or similar material in three strips or in U-section form shall be used, having a hardness
of 35 IRHD1) to 40 IRHD and resistant to sea water and ultraviolet light.
An alternative method, using metal casement putty with setting and location blocks, may be employed. The
blocks of resilient material shall be from 25 mm to 75 mm long and of such thickness as to ensure the glass
is centralized in the frame. They shall be positioned to maintain edge clearances during handling, transport
and installation.
Sufficient metal casement putty should be applied between glass, rebate and glazing strip so that when
glass and glazing strip have been pressed home, a bed of compound remains between the face of the glass,
rebate and glazing strip of not less than 2 mm. There should also be surplus of compound squeezed out
about the rebate which should be stripped at an angle, not undercut, to prevent water accumulating.
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BS MA 25:1973
m2 mm mm mm
Up to and including 0.28 5 19 6
Over 0.28 up to and including 0.75 6 25 8
Over 0.75 6 30 10
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BS MA 25:1973
7.2 Testing
To ensure that the windows and packing are watertight when fitted a hose test shall be carried out by the
shipbuilder to the owner’s or surveyor’s representative’s satisfaction, the test consisting of hosing the
window by means of a 20 mm nominal size hose held approximately 600 mm from the window and with a
water pressure of 172 kN/m2.
A similar test shall be carried out by the manufacturer before despatch, by means of batch tests at a
pressure not exceeding 172 kN/m2.
7.3 Inspection
The manufacturer shall afford the inspecting authority, the purchaser or his representative all reasonable
facilities to satisfy himself that the windows are in accordance with the requirements of this specification.
All inspections shall be carried out at the manufacturer’s works prior to despatch, unless otherwise agreed.
8 Identification
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All window frames shall be permanently marked with the following details.
1) Manufacturer’s name (or trade mark).
2) The number of this British Standard (i.e. BS MA 25).
3) The nominal dimension of the window frame.
4) The thickness of the glass to be fitted.
NOTE Attention is drawn to certification facilities offered by BSI; see the in side back cover of this Standard.
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Appendix B Suitable, apparatus for load stamp test of toughened safety glass
This Appendix describes the apparatus to be used for carrying out the load stamp test specified in 3.3.2.
The apparatus to be used for the testing of glass panes is illustrated in Figure 6a.
The dimensions of the punch to be used are given in Figure 6b.
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Figure 6a Figure 6b
Component
Component Material Specification
number
Of sufficient thickness to prevent
1 base plate steel deformation under pressure
Surface: flat
rubber, Thickness: 2 mm
2 flat ring
hardness 40–60 IRHDa Width: 15 mm minimum
Lower part flattened so that a diameter
3 punch steel
of 12.5 mm is obtained
felt Thickness: approx. 5 mm for felt or
4 pad or approx. 2 mm for fibre-board
fibre-board External diameter: approx. 50 mm
a International Rubber Hardness Degrees.
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BS MA 25:1973
Ships engaged only on voyages with not more than 250 passengers on board, to sea or in smooth or in
partially smooth waters in all cases in fine weather and during restricted periods, in the course of which
the ships are at no time more than 15 miles exclusive of any smooth waters from their point of departure
nor more than 3 miles from land.
L1
a = 1.0 + ---------
- for 2nd tier of unprotected fronts
120
L1
a = 0.5 + ---------
- for 3rd tier of unprotected fronts, for sides and for protected fronts
150
L1 x
a = 0.7 + --------------
- – 0.8 ---
- for aft ends of amidships
1 000 L
L1 x
a = 0.5 + --------------
- – 0.4 ---
- for aft ends forward of amidships
1 000 L
L = Length of ship (as defined in the Load Line Rules), in metres
L1 = Length of ship in metres (L1 shall not be taken greater than 300 m).
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BS MA 25:1973
x/L – 0.45 2
b = 1.0 + ---------------------------- for x/L u 0.45
C + 0.2
B
x/L – 0.45 2
b = 1.0 + 1.5 ---------------------------- for x/L W 0.45
C + 0.2
B
CB = block coefficient, 0.60 u CB u 0.80
NOTE When determining aft ends forward of amidships, CB need not be taken less than 0.80.
x = distance in metres between bulkhead considered and the aft perpendicular. When determining
sides of a deckhouse, the deckhouse is to be subdivided into parts of approximately equal length,
not exceeding 0.15L each, and x is to be taken as the distance between the aft perpendicular and
the centre of each part considered.
L – L/300 L 2
f = ------ e – 1 – ---------- for L u 150 m
10 150
L – L/300
f = ------ e for 150 m u L u 300 m
10
f = 11.30 for L W 300 m
y = vertical distance in metres from summer water line to midpoint of window
b'
c = 0.3 + 0.7 -----
B'
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b½ = breadth of deckhouse
B½ = actual maximum breadth of ship on the exposed weather deck at the position considered
NOTE b½/B½ is not to be taken less than 0.25.
The maximum allowable pressure head on toughened safety glass for standard sizes of ships’ windows is
given in Table 10.
Table 10 — Maximum allowable pressure head on toughened
safety glass for standard sizes of ships’ windows
Maximum allowable pressure head
10 mm 12 mm 15 mm 19 mm
mm × mm m m m m
300 × 425 9.90 14.20 22.20 35.70
355 × 500 7.10 10.20 15.90 25.50
400 × 560 5.60 8.00 12.50 20.10
450 × 630 4.40 6.30 9.90 15.90
500 × 710 3.60 5.10 8.00 12.80
560 × 800 2.80 4.10 6.40 10.20
900 × 630 2.20 3.20 5.00 8.10
1 000 × 710 2.50 4.00 6.40
1 100 × 800 3.10 5.00
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BS MA 25:1973
The maximum allowable pressure head for windows of non standard dimensions greater than those given
in Table 10 may be calculated from the following formula.
H =
where
H is the maximum allowable pressure head (metres),
t is the nominal thickness of glass (mm),
¶ is the factor from the curve in Figure 7,
b is the minor dimension of window (mm).
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BS MA
25:1973
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