Section 2 Principles
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Naval Ships, January 2023 - Volume 2 Machinery and Engineering Systems - Part 4 Propulsion Devices - Chapter 1 Propellers - Section 2 Principles

Section 2 Principles

Parent topic: Chapter 1 Propellers

2.1 Design and operating principles

2.1.1 Marine propellers are to be designed in accordance with user defined operating and performance criteria, taking account of ship type and service operating envelope. In multiscrew ships, consideration is to be given to operating modes where one or more propeller is out of service.

2.1.2 Marine propellers are to be capable of continuous operation between the maximum and minimum output power at specified operating conditions, see Vol 2, Pt 1, Ch 3, 4 Operating conditions and within the operational service profile required by Vol 2, Pt 4, Ch 1, 5.2 Plans 5.2.2 in this Chapter.

2.1.3 Marine propellers are to be designed and installed such that degradation or failure of any other propulsion system will not render the propeller inoperable.

2.1.4 Marine propellers are to be designed and installed such that power transmission can be maintained in the event of a single failure in an operational sub-system.

2.1.5 The propeller is to be capable of operating within defined vibration, cyclic or other loads during its service life.

2.1.6 Controllable pitch propellers shall be designed so that all blades are interchangeable and will fit into any blade seat on the hub.

2.2 Lifecycle principles

2.2.1 Propellers are to be operated and maintained such that the required performance, integrity and reliability can be achieved throughout the life of the ship.

2.2.2 To demonstrate continued compliance with the classification provisions for engineering systems (see Vol 2, Pt 1, Ch 1, 2.1 Provisions 2.1.1), surveys are to be carried out in accordance with the Regulations.

2.3 Enhanced assessment of manufacturing tolerance principles

2.3.1 Where the design of a propeller has used enhanced assessment methods for manufacturing tolerances as described in Vol 2, Pt 4, Ch 1, 8.4 Enhanced assessment of manufacturing tolerances – Fast ships and craft and Vol 2, Pt 4, Ch 1, 8.5 Enhanced assessment of propeller manufacturing tolerances – Noise reduced propellers, the ship will be eligible for the optional machinery class notation AP1 or AP2 as applicable. These optional class notations may be applied where the Owner requires detailed knowledge of a propeller's manufacturing tolerances and where noise or the effects of cavitation are required to be minimised for anticipated service conditions.

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