Section 1 General
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Ships, July 2022 - Part 4 Ship Structures (Ship Types) - Chapter 3 Tugs - Section 1 General

Section 1 General

Parent topic: Chapter 3 Tugs

1.1 Application

1.1.1 Sections 1 to 8 of this Chapter apply to tugs.

1.1.2  Pt 4, Ch 3, 9 Escort operation, performance numeral and trials of this Chapter applies to tugs and offshore supply ships intended to provide escort operation.

1.1.3 The scantlings and arrangements are to be as required by Pt 4, Ch 1 General Cargo Ships except as otherwise specified. The draught, T, used for the determination of scantlings is to be not less than 0,85D.

1.2 Class notations

1.2.1 Ships complying with relevant requirements will be assigned one or more of the class notations given in Table 3.1.1 Class notations.

1.2.2 Tugs intended to be operated only in suitable areas or conditions which have been agreed by the Committee, as defined in Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.6 to Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.10, will receive individual consideration on the basis of the Rules with respect to the environmental conditions agreed for the design basis and approval. In particular, tugs complying with the requirements of this Chapter and Pt 3, Ch 13, 7 Equipment for the relevant reduced equipment requirements, will be eligible to be classed:

  • A1 tug protected waters service; or
  • A1 escort tug protected waters service; or
  • A1 escort tug EPN (F,B,V,C) protected waters service; or
  • A1 escort tug EPN (CFD: F,B, V) protected waters service; or
  • 100A1 tug with service restriction notation; or
  • 100A1 escort tug with service restriction notation; or
  • 100A1 escort tug EPN (F,B,V,C) with service restriction notation; or
  • 100A1 escort tug EPN (CFD: F,B, V) with service restriction notation;

whichever is applicable.

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

Table 3.1.1 Class notations

Class Notation Applicable Sections
100A1 tug Pt 4, Ch 3, 1 General to Pt 4, Ch 3, 8 Fenders
100A1 escort tug Pt 4, Ch 3, 1 General to Pt 4, Ch 3, 9 Escort operation, performance numeral and trials, except Pt 4, Ch 3, 9.3 Performance numeral and trials and Pt 4, Ch 3, 9.4 Computational Fluid Dynamics Predicted Performance
100A1 escort tug EPN (F, B, V, C) Pt 4, Ch 3, 1 General to Pt 4, Ch 3, 9 Escort operation, performance numeral and trials except Pt 4, Ch 3, 9.4 Computational Fluid Dynamics Predicted Performance
100A1 escort tug EPN (CFD: F, B, V) Pt 4, Ch 3, 1 General to Pt 4, Ch 3, 9 Escort operation, performance numeral and trials, except Pt 4, Ch 3, 9.3 Performance numeral and trials

Note Tugs which comply with the anchor handler requirements in Pt 4, Ch 4, 1 General to Pt 4, Ch 3, 8 Fenders will be eligible for the additional notation anchor handler.

1.3 Information required

1.3.1 In addition to the information and plans required by Pt 3, Ch 1, 5 Information required, plans covering the following items are to be submitted for approval where applicable:

  • Support structure and foundations of towing equipment.
  • Skegs, propeller guards and other structures which support the weight of the vessel during dry-docking.

1.3.2 The following supporting documents are to be submitted for information:

  • Towing arrangements, including lines of action, magnitudes and corresponding points of application of towline pulls on towing equipment.
  • Details of the breaking strength of the components of the towline system, together with maximum pull and brake holding load, or equivalent, of towing winches where applicable.
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