Section 1 General

1.1.1 This Chapter applies to propelled and nonpropelled tankers (barges) of Types C, N Closed, N Open with flame arrestors and N Open, intended for the carriage of dangerous liquid oil and chemical cargoes of Classes 3, 6.1, 8 and 9 in bulk, in association with a List of Defined Chemical Cargoes and with class notations as indicated in Pt 4, Ch 6, 1.4 Class notation.

1.1.2 For further information on international regulations, the significance of tanker types and further information on dangerous liquids, see Pt 4, Ch 4 General Requirements For Tankers Carrying Dangerous Liquids in Bulk.

1.1.3 This Chapter mainly provides for requirements regarding structural aspects. For basic midship configurations and particular aspects and requirements regarding the design and arrangements of Type C and Type N tankers, see Pt 4, Ch 4 General Requirements For Tankers Carrying Dangerous Liquids in Bulk.

1.1.4 Alternative arrangements which are proposed as being equivalent to the Rules will receive individual consideration taking into account any relevant National Authority requirements.

1.1.5 The requirements of this Chapter take into account the European Provisions concerning the International Carriage of Dangerous Goods by Inland Waterway (ADN) which assume heavy traffic on relatively narrow waterways through heavily populated areas.

1.1.6 Ships intended to be used on waterways with conditions different from those stated in Pt 4, Ch 6, 1.1 Application 1.1.4 and where ADN requirements are not applicable will receive special consideration and the requirements may be modified to suit the actual conditions, see also Pt 4, Ch 4, 1.2 International Regulations.

1.1.7 Although the contents of this Chapter and those of Chapter 4 take ADN technical Regulations into account, the issue of an ADN certificate by or on behalf of the relevant Authorities, requires full compliance with their Regulations which are to be consulted in all cases.

1.1.8 Where requested to do so by the Builder or Owner, Lloyd’s Register (hereinafter referred to as LR) will investigate compliance with the ADN Regulations indicated in Pt 4, Ch 6, 1.1 Application 1.1.7 with a view to issuing a Statement of Compliance.

1.2.1 Self-propelled tankers are to have the machinery aft.

1.2.2 For ADN related requirements such as the arrangement of cofferdams, double sides (as applicable), service spaces and accommodations, entrances and the protection against the ingress of gases and special requirements for Type C and N tankers, see Pt 4, Ch 4, 3 Ship Arrangements.

1.2.3 The maximum tank capacity in accordance with the ADN is to be determined in accordance with Pt 4, Ch 4, 3.2 Hold spaces, cargo tanks and service spaces. The ADN, however, offers deviations of the prescribed tank capacities, provided the crashworthiness of the vessel is suitably increased. This may be achieved by one, or a combination of the following measures described in Pt 4, Ch 6, 1.3 Structural configuration 1.3.4.

1.2.4 Arrangements and scantlings forward and aft of the midship region are to comply with Pt 3, Ch 5 Fore End and Aft End Structure and Pt 3, Ch 6 Machinery Spaces so far as applicable. The remaining requirements of Part 3 are also to be complied with as appropriate for the intended arrangements.

1.3.1 The arrangement and requirements in the following Sections are for tankers having a length not exceeding 135 m, a ratio of length to depth not exceeding 35, a ratio of breadth to depth not exceeding 5 and the midship region as defined in Pt 3, Ch 3, 2.1 Definition of requirements. When the limiting length of the ship or ratio of L/D or B/D are exceeded, the scantlings may have to be determined by direct calculation, see Pt 3, Ch 1, 3.2 Alternative scantlings and Pt 3, Ch 4 Longitudinal Strength.

1.3.2 This Chapter provides for a basic structural configuration of ships having integral cargo tanks of the flush deck (Type C or Type N) or the trunk deck (Type N) type. It also provides for the structural configuration of ships having tanks independent from the ship’s structure, seePt 4, Ch 6, 8 Construction of tankers with cargo tanks independent from the ship’s structure and Pt 4, Ch 6, 9 Construction of cargo tanks independent from the ship’s structure.

1.3.3 The bottom, side shell and deck plating may be framed transversely or longitudinally or a combination of the two, but it is recommended that ships over 50 m in length be built according to the longitudinal framing system in bottom and deck.

1.3.4 In case the ship is provided with tanks exceeding the maximum tank capacity in accordance with the ADN as described in Pt 4, Ch 6, 1.2 Ship arrangement 1.2.3, one, or a combination of the following measures, need to be taken:

• Increase in sideshell and/or tank plating thicknesses, increase of stiffening arrangements or scantlings and spacings of primary members.
• Increase in the overall width of the double skin.
• Introduction of additional structural members.
• The appliance of special crashworthy structures.
• The use of alternative materials. The use of these materials is to be approved by the Society.

In the above cases, the increased collision capabilities are to be proven by additional direct and statistical calculations as required by the ADN. These calculations should be submitted to, and be approved by the Society.

1.4.1 The Regulations for classification and the assignment of class notations are given in Pt 1, Ch 2, 2 Character of classification and class notations.

1.4.2 Type C Tankers complying with the requirements of this Chapter and other relevant Rule requirements will be eligible to be classed:

together with the appropriate design pressure valve setting and design specific gravity and in association with a List of Defined Cargoes, e.g.:

1.4.3 Type N Closed Tankers complying with the requirements of this Chapter and other relevant Rule requirements will be eligible to be classed:

together with the appropriate design pressure valve setting and design specific gravity and in association with a List of Defined Cargoes, e.g.:

1.4.4 Type N Open Tankers with flame screens complying with the requirements of this Chapter and other relevant Rule requirements will be eligible to be classed:

together with the appropriate design specific gravity and in association with a List of Defined Cargoes, e.g.:

1.4.5 Type N Open Tankers complying with the requirements of this Chapter and other relevant Rule requirements will be eligible to be classed:

together with the appropriate design specific gravity and in association with a List of Defined Cargoes, e.g.:

1.4.6 Type N Tankers complying with the requirements of Pt 4, Ch 4, 3.7 Special requirements for Type N tankers 3.7.1 and other relevant ADN requirements will be eligible to receive the additional notation ‘Double Hull’, e.g.: ‘A1 I.W.W. Tanker Type N Closed, Double Hull, p.v. +25 kPa, S.G. 1.00 in association with a List of Defined Cargoes’.

1.4.7 Other notations, as appropriate to the arrangements, scantlings and service, may be assigned as provided for in Pt 1, Ch 2, 2 Character of classification and class notations.

1.5.1 The List of Defined Chemical Cargoes, for the carriage of which the ship has been approved, will be attached to the Classification Certificate.

1.5.2 Only those chemical cargoes which are included in the List of Defined Chemical Cargoes may be carried.

1.5.3 The List of Defined Cargoes will be issued by the Society and will be based on Table C of Part 3 of the ADN. Parameters will include the tanker type, cargo tank design and cargo tank type as well as the characteristics of all relevant equipment fitted in the cargo zone. All relevant requirements of Table C will be used as a basis for the list, including any relevant additional requirements contained in column 20. Attention is drawn to Pt 4, Ch 4, 1.5 Designation of dangerous liquids to ship types 1.5.3 and Pt 4, Ch 4, 1.5 Designation of dangerous liquids to ship types 1.5.4 in respect of material compatibility.

1.6.1 Additional notations may be assigned for the following features:

• Tanks constructed of corrosion resistant materials, e.g. stainless steel ‘CR (s.stl)’, or lined with corrosion resistant linings, e.g. rubber lining ‘CR (r.l)’.

1.7.1 Where it is intended to carry cargoes at temperatures higher than 80°C in integrated tanks, a thermal stress calculation needs to be submitted for verification of the scantlings and arrangements.

1.8.1 For materials and grades of steel, the use of materials and protection of steelwork, reference is made toPt 4, Ch 4, 2 Materials.

1.9.1 The material is to comply with the requirements of Ch 4, 2 Castings for ship and other structural applications and Ch 3, 7 Austenitic and duplex stainless steels of LR’s Rules for the Manufacture, Testing and Certification of Materials, July 2022 (hereinafter referred to as the Rules for Materials). Other types of stainless steel will be specially considered.

1.9.2 The use of clad stainless steel instead of solid stainless steel will be specially considered.

1.9.3 Where the specified minimum yield stress or 0,5 per cent proof stress at the operating steel temperature is less than 235 N/mm² (24 kgf/mm²), scantlings will have to be increased and will be specially considered.

1.10.1 Within the cargo tank region, including cofferdams and under deck pump-rooms, the thickness of all plating and structural members is to be not less than:

1.10.2 For stainless steel structures, the thickness obtained with 1.10.1 may be reduced by 0,5 mm.

1.11.1 For the information required to be submitted, see Pt 3, Ch 1, 5 Information required. In addition, the following are to be supplied:

1. The desired tanker type notation and the cargo tank type.

2. The opening pressure of the high velocity vent valves.

3. The proposed design cargo relative density (specific gravity).

4. Maximum cargo temperature in °C when loaded or carried.

5. Details of corrosion protection of cargo tanks, ballast spaces and void spaces if applied.

6. Details of materials to be used in the construction of the cargo tanks if not made of mild steel.

7. Loading sequence desired and data on any other nonuniform loading conditions that may be applicable.

8. The flag of the vessel and the country issuing statutory certificates.

9. Any other relevant information that may influence the design of the ship or the proceedings during the approval process.

1.12.1 The following symbols and definitions are applicable to this Chapter unless otherwise stated:

L, B, D, T are as defined in Pt 3, Ch 1, 6.1 Principal particulars

k_L is given in Table 2.1.1 Values of K_L