ISO 17939:2015

INTERNATIONAL ISO
STANDARD 17939
First edition
2015-09-01
Ships and marine technology — Oil
tank hatches
Navires et technologie maritime — Huile trappe
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
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ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Classifications . 1
3.1 Types. 1
3.2 Structure and main dimensions . 2
3.2.1 Type A1 . 2
3.2.2 Type A1F . 4
3.2.3 Type A2 . 4
3.2.4 Type A2F . 6
3.2.5 Type B . 6
3.2.6 Type BF . 8
3.2.7 Type C1 . 8
3.2.8 Type C1F .10
3.2.9 Type C2 .10
3.2.10 Type C2F .12
4 Materials .12
5 Quality of manufacture .13
5.1 Appearance .13
5.2 Rust-proof and surface treatment .13
5.3 Performance .13
6 Testing of watertightness .13
7 Designation .13
Foreword
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The committee responsible for this document is ISO/TC 8, Ships and marine technology, Subcommittee
SC 8, Ship design.
iv © ISO 2015 – All rights reserved

INTERNATIONAL STANDARD ISO 17939:2015(E)
Ships and marine technology — Oil tank hatches
1 Scope
This International Standard specifies the classification, structure and main dimensions, materials,
quality of manufacture, testing of watertightness and designation for oil tank hatches for application on
board ships in order to ensure interchangeability of the hatches. The remaining dimensions, welding,
and other details are left to the manufacturer.
These hatches generally conform to the requirements of the International Convention on Load Lines
1966 (ILLC66). These structures and specifications of oil-tight hatch covers in this International
Standard meet IACS UR S26 requirements. The possibility for application in position 1 and position 2
has to be considered for each situation and, where necessary, the hatch covers shall be provided with
additional stiffening.
This International Standard is applicable to the design, manufacturing, and test of accommodation
ladders, as well as accommodation ladder used specifically in combination with pilot ladder (hereinafter
referred as “pilot accommodation ladder”).
Users of this International Standard should note that while observing the requirements of this
International 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.
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 8501–1, Preparation of steel substrates before application of paints and related products — Visual
assessment of surface cleanliness — Part 1: Rust grades and preparation grades of uncoated steel substrates
and of steel substrates after overall removal of previous coatings.
3 Classifications
3.1 Types
Oil tank hatches are divided into the following types, see Table 1.
Table 1 — Classification of oil tank hatches
Dimensions in millimetres
Application in
accordance with
Types Definition Nominal size
ILLC66
in position (s)
A1 circular flat hatch cover 2
A1F circular flat hatch cover with stiffener 1
600, 700, 800,
A (circular)
900, 1 000, 1 200
A2 circular curve hatch cover 2
A2F circular curve hatch cover with stiffener 1
B long circular hatch cover 600 × 800, 750 × 1 200, 2
B (long circular) 750 × 1 300,
BF long circular hatch cover with stiffener 1
750 × 1 500, 850 × 1 500
flat hatch cover
C1 2
(upper circular, lower long circular)
a
750 (750 × 1 200)
flat hatch cover with stiffener
C1F a 1
C (upper circular, 750 (750 × 1 300)
(upper circular, lower long circular)
a
lower long 750 (750 × 1 500)
curve hatch cover
a
circular) 850 (850 × 1 500)
C2 2
(upper circular, lower long circular)
a
900 (900 × 1 500)
curve hatch cover with stiffener
C2F 1
(upper circular, lower long circular)
a
The data between parentheses are the size of lower long circular.
3.2 Structure and main dimensions
3.2.1 Type A1
Structure and main dimensions of type A1 hatch cover shall conform to the detail of Figure 1 and
Table 2.
2 © ISO 2015 – All rights reserved

Dimensions in millimetres
4 5
D₁
D
11 12
Key
1 coaming 8 lock catch
2 bearing 9 wing clamp
3 actuator 10 stiffener
4 junction plate 11 measuring hole cover (optional)
5 cover plate 12 clamp plate
6 seal ring 13 bearing pad welded on the bracket of a toggle bolt for metal to metal contact
7 clamping ring
NOTE Thickness of coaming shall comply with the related requirements, such as the requirements of
classification societies.
Figure 1 — Structure of type A1 hatch
Table 2 — Main dimensions of type A1 and type A1F
Dimensions in millimetres
Nominal sizes Deck opening sizes
H t Number of clips
D D
600 570 4
700 670
800 770
≥600
900 870 6
1 000 970
1 200 1 170
H
t
3.2.2 Type A1F
Structure and main dimensions of type A1F hatch cover shall conform to the detail of Figure 2 and
Table 2.
Dimensions in millimetres
4 5
≥M20
D₁
12 (min. 16 mm gross)
D
-75 × 10
11 12
Key
1 coaming 8 lock catch
2 bearing 9 wing clamp
3 actuator 10 stiffener
4 junction plate 11 measuring hole cover (optional)
5 cover plate 12 clamp plate
6 seal ring 13 bearing pad welded on the bracket of a toggle bolt for metal to metal contact
7 clamping ring
NOTE Thickness of coaming shall comply with the related requirements, such as the requirements of
classification societies.
Figure 2 — Structure of type A1F hatch
3.2.3 Type A2
Structure and main dimensions of type A2 hatch cover shall conform to the detail of Figure 3 and
Table 3.
4 © ISO 2015 – All rights reserved
H
t
Dimensions in millimetres
D₁
D
Key
1 coaming 7 clamping ring
2 bearing 8 lock catch
3 actuator 9 wing clamp
4 connecting rod 10 measuring hole cover (optional)
5 cover plate 11 clamp plate
6 seal ring 12 bearing pad welded on the bracket of a toggle bolt for metal to metal contact
NOTE Thickness of coaming shall comply with the related requirements, such as the requirements of
classification societies.
Figure 3 — Structure of type A2 hatch
Table 3 — Main dimensions of type A2 and type A2F
Dimensions in millimetres
Nominal sizes Deck opening sizes
H t Number of clips
D D
600 570 4
700 670
800 770
≥600
900 870 6
1 000 970
1 200 1 170
t
H
t
3.2.4 Type A2F
Structure and main dimensions of type A2F hatch cover shall conform to the detail of Figure 4 and
Table 3.
Dimensions in millimetres
3 4
5 6
≥M20
12 (min. 16 mm gross)
D₁
D
-75 × 10
910 12
Key
1 coaming 8 lock catch
2 bearing 9 wing clamp
3 actuator 10 stiffener
4 connecting rod 11 measuring hole cover (optional)
5 cover plate 12 clamp plate
6 seal ring 13 bearing pad welded on the bracket of a toggle bolt for metal to metal contact
7 clamping ring
NOTE Thickness of coaming shall comply with the related requirements, such as the requirements of
classification societies.
Figure 4 — Structure of type A2F hatch
3.2.5 Type B
Structure and main dimensions of type B hatch cover shall conform to the detail of Figure 5 and Table 4.
6 © ISO 2015 – All rights reserved
t
H
Dimensions in millimetres
4 5
A₁ × B₁
A × B
11 12
Key
1 coaming 8 lock catch
2 bearing 9 wing clamp
3 actuator 10 stiffener
4 junction plate 11 measuring hole cover (optional
...