Section 1 General requirements
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 2 Prime Movers - Chapter 2 Gas Turbines - Section 1 General requirements

Section 1 General requirements

Parent topic: Chapter 2 Gas Turbines

1.1 Definitions

1.1.1 For the purposes of this Chapter, a gas turbine package is part of a larger system (e.g. the propulsion system) providing power for main propulsion, manoeuvring and/or other Mobility systems and Ship Type systems and is considered to be a series of elements, including all equipment and associated sub-systems necessary to provide specified functions within the intended context of use in the system.

1.1.2 The principal elements of a gas turbine package are:

  1. The gas turbine unit, comprising:

    • gas generator (inlet, compressor, combustion system, etc.);
    • power turbine;
    • engine management bleed air system;
    • accessory gearbox and
    • HP fuel systems.

  2. The on-engine instrumentation and engine control system, the means for monitoring, control and protection of the gas turbine, comprising:

    • hardware, sensors, control cables, processors and cabinets and
    • software.

  3. The gas turbine package installation, comprising:

    • mounting arrangements that support the gas turbine to maintain shaft alignment and which provide the required levels of shock/vibration/noise attenuation; where appropriate, this includes the base frame mounts;
    • package enclosure (where provided), including, where appropriate, the base frame supporting the gas turbine unit (and alternator);
    • package drains;
    • arrangements for lubricating the gas turbine unit and, where relevant, the alternator;
    • arrangements for air cooling of gas turbine and equipment;
    • combustion air inlet plenum and exhaust collector;
    • gas turbine start system (off-unit components);
    • fire protection arrangements (covering detection, containment and suppression of fire);
    • intercooler and recuperator systems fitted to the gas turbine;
    • combustion air filtration and arrangements to prevent ingestion of foreign objects;
    • package control system, the means for monitoring, control and protection of the package, including arrangements for maintaining its power supply against loss of ship’s supply.

  4. For an integrated gas turbine generator unit, the gas turbine package also includes:

    • alternator, including arrangements for its ventilation/cooling and bearing lubrication and for voltage/frequency control plus
    • high speed coupling shaft (alternator drive shaft).

1.1.3 A gas turbine system consists of the gas turbine unit plus its control, monitoring, alert and safety systems. See Vol 2, Pt 2, Ch 2, 1.1 Definitions 1.1.2 and Vol 2, Pt 2, Ch 2, 1.1 Definitions 1.1.2.(b).

1.1.4 Mobility and/or Ship Type support services/ship interfaces include:

  1. combustion air supply ducting;

  2. exhaust ducting;

  3. provisions for package ventilation/air cooling;

  4. ship’s cooling water supply;

  5. ship’s drains;

  6. fuel supply system;

  7. electrical power supplies for engine operation, including connections to/from uninterruptible power supplies;

  8. appropriate connections with the ship’s control, monitoring, alert and safety systems for remote monitoring/control of the gas turbine package;

  9. provision to duct away engine bleed air and

  10. arrangements for wet washing gas turbines, supply of washing water and detergents/cleaning agents, and collection arrangements for dirty wash water.

1.1.5 Safety critical systems/components are those which provide functions intended to protect persons from physical hazards caused by engineering system failures, e.g. fire, explosion, or to prevent mechanical damage which may result in the loss of a Mobility Category System.

1.1.6 A Platform Management System provides centralised access to the ship’s control, monitoring, alert and safety system functionalities.

1.2 Standard reference conditions

1.2.1 Where power, efficiency, heat rate or specific consumption refer to standard conditions (ISO 2314), such conditions are to be:

  1. for the intake air at the compressor flange (compressor intake flare):

    • a total pressure of 101,3 kPa;
    • an ambient temperature of 15°C;
    • a relative humidity of 60 per cent; and

  2. for the exhaust at the turbine exhaust flange (or recuperator outlet):

    • a static pressure of 101,3 kPa.
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