Section 1 General

1.1.1 This Chapter applies to propelled and non-propelled tankers (barges) of Type G, intended for the carriage of dangerous liquids of Class 2 in bulk, in association with a List of Defined Chemical Cargoes and with class notations as indicated in Pt 4, Ch 5, 1.5 List of Defined Cargoes. Although the ships will be primarily designed for the carriage of Class 2 liquids they could also be entitled to carry products of Classes 3, 6.1, 8 and 9 as permitted by the ADN.

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

1.1.3 For further information on dangerous liquids, see Pt 4, Ch 5, 2 Cargo characteristics and requirements for carriage.

1.1.4 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 G tankers, see Pt 4, Ch 4 General Requirements For Tankers Carrying Dangerous Liquids in Bulk.

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

1.1.6 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.

1.1.7 Ships intended to be used on waterways with conditions different from those stated in Pt 4, Ch 5, 1.1 Application 1.1.6 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.

1.1.8 Although the contents of this Chapter and those of Pt 4, Ch 4 General Requirements For Tankers Carrying Dangerous Liquids in Bulk 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.

1.1.9 Where requested to do so by the Builder or Owner, LR will investigate compliance with the ADN Regulations indicated in Pt 4, Ch 5, 1.1 Application 1.1.8 with a view to issuing a Statement of Compliance.

1.2.1 The ship is to be so arranged that the cargo is carried in pressure tanks independent from the ship’s structure.

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

1.2.3 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 G tankers, see Pt 4, Ch 4, 3 Ship Arrangements.

1.2.4 Individual cargo tanks are to be protected, as far as possible, against collision damage. The requirements are deemed to have been met if:

1. The side shell is reinforced by side shell stringers supported by web frames over the cargo compartment length in accordance with Pt 4, Ch 4, 3.5 Special requirements for Type G tankers or

2. longitudinal bulkheads are fitted at least 800 mm from the side shell over the cargo compartment length.

For details, see Pt 4, Ch 5, 8.4 Reinforcement of single skin side shell and Pt 4, Ch 5, 9 Longitudinal bulkheads.

1.2.5 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 crash worthiness of the vessel is suitably increased. This may be achieved by one, or a combination of the measures described in Pt 4, Ch 5, 1.3 Structural configuration 1.3.5.

1.2.6 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.

1.2.7 The number and disposition of transverse bulkheads are to be as required by Pt 3, Ch 7 Bulkheads. Watertight transverse bulkheads without openings are to be fitted at the ends of the cargo compartment space.

1.3.1 This Chapter provides for a basic structural configuration of a single flush deck or trunk deck hull with single or double bottom arrangement and single or double skin side construction in way of the cargo compartment space, the cross-section of the ship in way of the cargo compartment space in general being in accordance with Figure 4.1.2 Examples of possible hull configurations for Tankers of the Types G. C and N, for Type G ships in Chapter 4.

1.3.2 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 30, a ratio of breadth to depth not exceeding five 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.

1.3.3 Transverse or longitudinal framing may be adopted. For ships having a length, L, of not less than 50 m, it is recommended longitudinal framing be applied to deck, trunk sides and trunk deck in association with either longitudinal framing in the bottom or transverse framing in the bottom with additional efficient longitudinal stiffening integral with the tank supports. Longitudinal framing adopted for deck and/or bottom in ships with longitudinal bulkheads according to Pt 4, Ch 5, 1.2 Ship arrangement 1.2.4.(b) may be restricted to the areas between the longitudinal bulkheads.

1.3.4 For ADN related structural requirements regarding double and single hull structures, the arrangements of cargo tank supports and miscellaneous structural requirements, see Pt 4, Ch 4, 3.5 Special requirements for Type G tankers.

1.3.5 In case the ship is provided with tanks exceeding the maximum tank capacity in accordance with the ADN as described in Pt 4, Ch 5, 1.2 Ship arrangement 1.2.5 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.

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 Ships complying with the applicable 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 Chemical Cargoes, e.g.: ‘A1 I.W.W. Tanker Type G’ p.v. +400 kPa, S.G. 1.00 in association with a List of Defined Cargoes.

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

1.5.2 Only those cargoes which are included in the List of Defined 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 parameters of Table C will be used as a basis for the list, including any relevant additional requirements contained in column 20. Attention is also drawn to Pt 4, Ch 4, 1.5 Designation of dangerous liquids to ship types in respect of material compatability.

1.6.1 Additional notations may be assigned for the following features:

1. 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)'.

2. Minimum cargo temperature in °C for which the cargo tanks have been approved.

3. Ambient design temperatures (when the carrier is suitable for continuous service in high and/or low temperature climatic conditions).

1.7.1 For materials and grades of steel, the use of materials and protection of steelwork reference is made to Pt 4, Ch 4, 2 Materials. The materials and grades of steel used in the construction of the cargo pressure tanks are to comply with the requirements of Pt 5, Ch 9 Pressure Vessels other than Boilers, taking into account the minimum temperature and maximum pressure of the cargo, also the maximum temperature if heating arrangements are fitted.

1.8.1 The material is to comply with the requirements of Ch 8, 2 Aluminium alloy rivets and Ch 3, 7 Austenitic and duplex stainless steels of Lloyd’s Register’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.

1.8.2 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 be specially considered.

1.9.1 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 design pressure of the cargo tanks.

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

3. Details of corrosion protection of cargo tanks, ballast spaces and void spaces where applicable.

4. Details of insulation on cargo tanks (if applicable).

5. Details of materials of cargo tanks.

6. Design loading sequence including data on non-uniform loading conditions that may be applicable.

7. Particulars of filling, discharging, venting, relieving and inerting arrangements so far as applicable. Where filling, or discharging is carried out by vapour pressure, inert gas pressure or similar, the maximum pressure should be given.

8. Details of temperature control arrangements if required or proposed to be installed.

9. Details of tanks or spaces in the ship which will be used for carrying ballast water.

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

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

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

L, B, D and C_b 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