Section 1 General

1.1.1 This Chapter applies to ferries and roll on-roll off ships defined as follows:

1. A ferry is a self-propelled ship, designed primarily for the carriage of vehicles and/or passengers on a regular scheduled service of short duration.

2. A roll on-roll off ship is a self-propelled ship with machinery aft or a non-propelled ship, designed primarily for the carriage of vehicles and for cargo loaded/unloaded by wheeled vehicles.

1.1.2 The structural requirements of this Chapter are intended to cover the midship region, as defined in Pt 3, Ch 3, 2.2 Definition of midship region for ships having a length not exceeding 125 m, a ratio of length to depth not exceeding 33 and a ratio of breadth to depth not exceeding five.

1.1.3 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 Pt 3 Ship Structures (General) are also to be complied with, as appropriate to the intended arrangements.

1.1.4 The scantlings and arrangements are to be as required in Pt 3, Ch 1 General as far as applicable or as specified otherwise in this Chapter.

1.1.5 For ferries carrying passengers, the requirements of Pt 4, Ch 9 Passenger Ships are also to be complied with so far as applicable.

1.2.1 This Chapter provides for a basic structural configuration of a single flush deck or a multi-deck hull with a single or double bottom arrangement and a single skin side construction, see Figure 2.1.1 Configuration with single flush deck or a multi-deck hull with a single or double bottom arrangement and a single skin side construction, and for a basic structural configuration of a single deck hull with a long wide hatch opening, a double bottom and a double skin side construction, see Figure 2.1.2 Configuration of a single deck hull with a long wide hatch opening, a double bottom and double skin side construction.

1.2.2 Longitudinal or transverse framing may be adopted. Ships with a ratio of length to depth exceeding 25 or a length, L, over 70 m and having a double bottom, are generally to be constructed with longitudinal framing in the bottom. Alternatively, transverse framing may be adopted provided suitable longitudinal stiffening is fitted to the bottom plating.

1.2.3 The number and disposition of transverse bulkheads are to be as required by Pt 3, Ch 7 Bulkheads. Additional bulkheads many have to be fitted to provide for sufficient transverse strength of the ship. Web frames are to be fitted in line with deck transverses and floors, forming a ring system.

1.3.1 Ships complying with the relevant requirements of this Chapter will be eligible to be classed ‘A1 I.W.W. ferry’, ‘A1 I.W.W. roll on-roll off ship’ or ‘A1 I.W.W. roll on-roll off barge’, whichever is applicable.

1.3.2 The Regulations for classification and assignment of class notations are given in Pt 1, Ch 2 Classification Regulations, to which reference should be made on the survey request form.

1.3.3 Where a ship has been specially designed, modified and/or arranged in accordance with the additional requirements for Zones 2 or 1, for service extension, for any special loading or discharging sequence or for navigation in ice, the appropriate class notation will be assigned.

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

1. Cargo loading on inner bottom and if applicable, also on hatchways and deck, see Pt 3, Ch 3, 4 Design loading.

2. Details of wheeled vehicles to be used, see Pt 3, Ch 9, 2.2 Loading.

3. The maximum pressure head in service on tanks, also details of any tanks interconnected with side tanks if fitted.

4. Details of tanks which will be solely used for water ballast in the light condition and which will be empty in the loaded condition.

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

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