Section 2 Materials

2.1 General

2.1.1 All materials, including steel castings and forgings used for sternframes, rudders, rudder stocks, rudder pintles, rudder palm bolts and propeller shaft brackets, are to comply with the relevant sections of the Rules for the Manufacture, Testing and Certification of Materials, July 2022 and Pt 3, Ch 2 Materials of the Rules and Regulations for the Classification of Ships, July 2022, except as indicated in Ch 4, 2.2 Rolled steel plates, strip, sections and bars and Ch 4, 2.3 Protection of steelwork of these Rules.

2.1.2 The requirements for welding are given in Pt 3, Ch 10 Welding and Structural Details of the Rules and Regulations for the Classification of Ships, July 2022 and Ch 13 Requirements for Welded Construction of the Rules for the Manufacture, Testing and Certification of Materials, July 2022.

2.2 Rolled steel plates, strip, sections and bars

2.2.1 Steel, when manufactured in accordance with Canadian Standards Association (CSA) G40.21 may be accepted as equivalent to LR grades, see Table 4.2.1 CSA Equivalent Steel Grades. This is subject to the steel being certified by LR and manufactured at a steel works approved for the manufacture of the equivalent LR grade. The CSA grade is to have the same condition of supply and combination of grain refining elements as the LR approved grades.

Table 4.2.1 CSA Equivalent Steel Grades

LR Grade	CSA Grade - MPa
	260W	260WT	300W	300WT	350W	350WT
	CSA Grade – (k.s.i)
	(38W)	(38WT)	(44W)	(44WT)	(50W)	(50WT)
A	√	√	√	√	√	√
B	(1)	CSA category 2⁽²⁾	(1)	CSA category 2⁽²⁾	(1)	CSA category 2⁽²⁾
D	–	CSA category 3	–	CSA category 3	–	CSA category 3
E	–	CSA category 4	–	CSA category 4	–	CSA category 4
AH27S	(1)	CSA category 2⁽²⁾	(1)	CSA category 2⁽²⁾	(1)	CSA category 2⁽²⁾
DH27S	–	CSA category 3	–	CSA category 3	–	CSA category 3
EH27S	–	CSA category 4	–	CSA category 4	–	CSA category 4
AH32	–	–	(1)	CSA category 2⁽²⁾	(1)	CSA category 2⁽²⁾
DH32	–	–	–	CSA category 3	–	CSA category 3
EH32	–	–	–	CSA category 4		CSA category 4
AH36	–	–	–	–	(1)	CSA category 2⁽²⁾
DH36	–	–	–	–	–	CSA category 3
EH36	–	–	–	–	–	CSA category 4
Note 1. Steel may be accepted with a thickness of t ≤ 12,5 mm when supplied in the fine grained condition, and for thicknesses in the range of 12,5 mm < t ≤ 50 mm, steel may be accepted subject to it being fine grained and normalised. Additionally, for thicknesses in the range of 12,5 mm < t ≤ 50 mm, the IIW carbon equivalent value (CEV) is to be less than 0,45 per cent. Note 2. Steel may be accepted under CSA category 1 if the actual certified Charpy value exceeds 27 Joules for normal strength and higher strength 27S steels, and exceeds 31 Joules for higher strength 32 and exceeds 34 joules for higher strength 36 steels.

2.2.2 The frequency of testing is to be as stated in the Rules for Materials for the equivalent grade.

2.2.3 The limit for the specified minimum yield stress in mild steel is stated in Pt 3, Ch 2, 1.2 Steel 1.2.1 of the Rules for Ships. Steel having a higher specified minimum yield stress is regarded as higher tensile steel.

2.2.4 For the determination of the hull girder section modulus where higher tensile steel is used, a higher tensile steel factor k _L as given in Table 2.1.1 Values of k L of the Rules for Ships will apply.

2.3 Protection of steelwork

2.3.1 Pt 3, Ch 2, 3 Corrosion protection of the Rules and Regulations for the Classification of Ships, July 2022 is applicable except that for vessels for freshwater service only, it may be considered suitable not to apply protection to the underwater portion of the hull. The limit of service for freshwater operation is the St. Lawrence River, west of the eastern end of the Ile d’Orleans, see Figure 4.1.1 Sketch of the map of the Gulf of St. Lawrence and River St. Lawrence showing the seaward and freshwater limits of service.

2.3.2 The requirements of Pt 4, Ch 1, 2.2 Protection of steelwork 2.2.2 to Pt 4, Ch 1, 2.2 Protection of steelwork 2.2.3 of the Rules and Regulations for the Classification of Ships, July 2022 are to be complied with, except that the increase of 5 mm min. on the inner bottom plating, for cargoes to be regularly discharged by grabs, as per Pt 4, Ch 1, 2.2 Protection of steelwork 2.2.2 on self-unloading bulk carriers, under the cargo holds, may be omitted.

2.4 Structural details

2.4.1 The requirements specified in Pt 3, Ch 10, 5.2 Arrangements at intersections of continuous secondary and primary members of the Rules for Ships, are applicable except that when using Table 10.5.1 Total load transmitted to connection of secondary members, in determination of the loads, D ₂, in metres is to be taken as the least of D or 1,6T or T + C _wL. C _wL is to be as defined in Ch 4, 5.1 General 5.1.3.