Section 2 Materials for hull construction at low temperatures – Winterisation H
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Clasifications Register Rules and Regulations - Rules for the Winterisation of Ships, July 2022 - Chapter 1 Rules for the Winterisation of Ships - Section 2 Materials for hull construction at low temperatures – Winterisation H

Section 2 Materials for hull construction at low temperatures – Winterisation H

Parent topic: Chapter 1 Rules for the Winterisation of Ships

2.1 Hull construction materials

2.1.1 The requirements in Ch 1, 2.1 Hull construction materials 2.1.2 are to provide steel grades with suitable notch toughness based on the thickness of the material and the location of the material. See Ch 3 Rolled Steel Plates, Strip, Sections and Bars of the Rules for the Manufacture, Testing and Certification of Materials, July 2022, for the properties and testing of steel grades.

2.1.2 The hull construction materials of exposed members identified in Table 1.2.1 Material classes and grades and Figure 1.2.1 Distribution of material classes for cold weather are to comply with Table 1.2.2 Materials for Class I, Table 1.2.3 Materials for Class II and Table 1.2.4 Materials for Class III.

2.1.3 Where the material class in Table 2.2.1 Material classes and grades of the Rules and Regulations for the Classification of Ships, July 2022 is higher than in Table 1.2.1 Material classes and grades and Figure 1.2.1 Distribution of material classes for cold weather, the higher material class is to be applied.

2.1.4 In addition to the requirements of Table 1.2.1 Material classes and grades and Figure 1.2.1 Distribution of material classes for cold weather, miscellaneous attachments are to comply with Table 1.2.5 Material classes and grades.

Table 1.2.1 Material classes and grades

Structural member category Material class
Within 0,4L amidships Outside 0,4L amidships
SECONDARY:
  • Deck plating exposed to weather, in general
  • Side plating above CWL, see Note 5
  • Transverse bulkheads above CWL, see Notes 5 and 6
I I
PRIMARY:
  • Strength deck plating
  • Continuous longitudinal members above strength deck, excluding longitudinal hatch coamings
  • Longitudinal bulkhead above CWL, see Notes 5 and 6
  • Top wing tank bulkhead above CWL, see Notes 5 and 6
II I
SPECIAL:
  • Sheerstrake at strength deck, see Note 1
  • Stringer plate in strength deck, see Note 1
  • Deck strake at longitudinal bulkhead, see Note 2
  • Continuous longitudinal hatch coamings, see Note 3
III II

Note 1. Not to be less than Grade E/EH within 0,4L amidships in ships with length exceeding 250 m.

Note 2. In ships with breadth exceeding 70 m at least three deck strakes are to be Class III.

Note 3. Not to be less than Grade D/DH.

Note 4. Within 0,4L amidships, single strakes which are required to be of Class III or of Grade E/EH or FH are to have breadths not less than 800 + 5L, but need not be greater than 1800 mm.

Note 5. The Cold Waterline (CWL) is to be taken as 0,3 m below the minimum design Ballast Waterline (BWL), see Figure 1.2.1 Distribution of material classes for cold weather.

Note 6. Applicable to plating attached to hull envelope plating exposed to cold air. At least one strake is to be considered in the same way as exposed plating and the strake width is to be at least 600 mm. If thermal stress calculations are performed then the extent of plate requiring consideration is to be adjusted accordingly.

Note 7. L is defined in Pt 3, Ch 1, 6.1 Principal particulars 6.1.1 of the Rules and Regulations for the Classification of Ships, July 2022.

Table 1.2.2 Materials for Class I

Thickness,

mm

 External design air temperature
−24°C to −28°C –29°C to –38°C –39°C to –48°C –49°C to –58°C –59°C to –68°C
MS HT MS HT MS HT MS HT MS HT
t ≤ 10 A AH A AH B AH D DH D DH
10 < t ≤ 15 A AH B AH D DH D DH D DH
15 < t ≤ 20 A AH B AH D DH D DH E EH
20 < t ≤ 25 B AH D DH D DH D DH E EH
25 < t ≤ 30 B AH D DH D DH E EH E EH
30 < t ≤ 35 D DH D DH D DH E EH E EH
35 < t ≤ 45 D DH D DH E EH E EH n/a FH
45 < t ≤ 50 D DH E EH E EH n/a FH n/a FH
Note 1. See Ch 3 Rolled Steel Plates, Strip, Sections and Bars of the Rules for the Manufacture, Testing and Certification of Materials, July 2022, for the properties and testing of steel grades.
Note 2. MS and HT are defined as Mild Steel and High Tensile Steel respectively.

Table 1.2.3 Materials for Class II

Thickness, mm External design air temperature
−24°C to −28°C −29°C to −38°C −39°C to −48°C −49°C to −58°C −59°C to −68°C
MS HT MS HT MS HT MS HT MS HT
t ≤ 10 A AH B AH D DH D DH E EH
10 < t ≤ 20 B AH D DH D DH E EH E EH
20 < t ≤ 30 D DH D DH E EH E EH n/a FH
30 < t ≤ 40 D DH E EH E EH n/a FH n/a FH
40 < t ≤ 45 E EH E EH n/a FH n/a FH n/a n/a
45 < t ≤ 50 E EH E EH n/a FH n/a FH n/a n/a
Note 1. See Ch 3 Rolled Steel Plates, Strip, Sections and Bars of the Rules for the Manufacture, Testing and Certification of Materials, July 2022, for the properties and testing of steel grades.
Note 2. MS and HT are defined as Mild Steel and High Tensile Steel respectively.

Table 1.2.4 Materials for Class III

Thickness, mm External design air temperature
−24°C to −28°C −29°C to −38°C −39°C to −48°C −49°C to −58°C −59°C to −68°C
MS HT MS HT MS HT MS HT MS HT
t ≤ 10 B AH D DH D DH E EH E EH
10 < t ≤ 20 D DH D DH E EH E EH n/a FH
20 < t ≤ 25 D DH E EH E EH E FH n/a FH
25 < t ≤ 30 D DH E EH E EH n/a FH n/a FH
30 < t ≤ 35 E EH E EH n/a FH n/a FH n/a n/a
35 < t ≤ 40 E EH E EH n/a FH n/a FH n/a n/a
40 < t ≤ 50 E EH n/a FH n/a FH n/a n/a n/a n/a
Note 1. See Ch 3 Rolled Steel Plates, Strip, Sections and Bars of the Rules for the Manufacture, Testing and Certification of Materials, July 2022, for the properties and testing of steel grades.
Note 2. MS and HT are defined as Mild Steel and High Tensile Steel respectively.

Figure 1.2.1 Distribution of material classes for cold weather

Table 1.2.5 Material classes and grades

Structural member External design air temperature for structural member °C Material class
Exposed structures of length greater than 0,09L and subjected to hull girder stress t Constructed of the same material class to that of the material to which they are attached, however need not be greater than class II
Hatch coamings, hatch covers, crane pedestals and windlass seats t + 5 Constructed of the same material class to that of the material to which they are attached, or class II, whichever is the greater
Forecastle deck t + 10 Class II
External bulkheads of accommodation block t + 20 Class II
Forecastle side shell plating
Plating and stiffeners attached and contiguous to the exposed boundary plating distance 'x', see Figure 1.2.1 Distribution of material classes for cold weather and Note 2 t + 10 Class I, but need not be taken greater than D or DH
Other exposed structures of length less than 0,09L, e.g. bulwarks, breakwaters, unlagged gas turbine intake structures, side screens, etc. Need not be taken lower than –33 Class I
Stern frames, rudders, rudder horns, shaft brackets and stem (including the strake of shell plating to which the item is attached) Fully immersed t + 20 Class II
Periodically immersed or exposed t

Note 1. For built-up stiffeners within the distance ‘x’, the web and flange are considered to be a single stiffening member and both members are to comply with the material requirements. For bulb stiffeners and stiffeners with the flange outside the distance ‘x’, the web only may be required to comply with the material requirements.

2.1.5 Steel plate materials for stern frames, rudders, rudder horns, shaft brackets, and stem (including the strake of shell plating to which the item is attached) and internal members attached to these items are to be in accordance with Table 1.2.2 Materials for Class I, Table 1.2.3 Materials for Class II and Table 1.2.4 Materials for Class III, using the appropriate temperature in Table 1.2.5 Material classes and grades. The steel casting and forging materials for the rudders, rudder stocks, rudder horns, shaft brackets, stern frames and stem are to be in accordance with Table 1.2.2 Materials for Class I, Table 1.2.3 Materials for Class II and Table 1.2.4 Materials for Class III, using the appropriate temperature in Table 1.2.6 Steel casting and forging materials for rudder, rudder horn, rudder stock, shaft bracket, stern.

2.1.6 The materials for cast anchors are to be in accordance with Ch 10, 1.4 Cast steel anchors of the Rules for the Manufacture, Testing and Certification of Materials, July 2022, and anchor chain cables are to be, at least, grade U3, suitably Charpy tested and confirmed for the external design air temperature.

2.1.7 Welding consumables are to be suitable for the applicable steel grades, see Ch 11 Approval of Welding Consumables of the Rules for the Manufacture, Testing and Certification of Materials, July 2022.

Table 1.2.6 Steel casting and forging materials for rudder, rudder horn, rudder stock, shaft bracket, stern

Item Condition External design air temperature for item,°C Steel grade (see Notes 1,2 and 3)
Casting Forging
Rudder horn & Shaft brackets Fully immersed t + 20 Special Grade Structural
Periodically immersed or exposed t Ferritic Grade or Ni steel Ferritic
Rudder & Rudder stock Fully immersed t + 20 Normal Grade Structural
Periodically immersed or exposed t Ferritic Grade or Ni steel Ferritic
Stern frame Fully immersed t + 20 Special Grade Structural
Periodically immersed or exposed t Ferritic Grade Ferritic
Stem, (including the strake of shell plating to which the item is attached) Fully immersed t + 20 Normal Grade Structural
Periodically immersed or exposed t Ferritic Grade or Ni steel Ferritic

Note 1 For ferritic grade cast steel, see Ch 4, 7 Ferritic steel castings for low temperature service of the Rules for Materials or equivalent to achieve an average Charpy energy of 27J at the testing air temperature t + 5°C, or -20°C, whichever is lower.

Note 2 For forgings installed without welding, the Charpy testing temperature may be increased by +20°C, but is not to be taken higher than 0°C, as in Table 1.3.5 Charpy testing temperature (°C) for all classes.

Note 3 For forgings, see Ch 5 Steel Forgings of the Rules for the Manufacture, Testing and Certification of Materials, July 2022.

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