6.5 Emergency conditions due to drilling operations
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - International Codes - 2009 MODU Code - Code for the Construction and Equipment of Mobile Offshore Drilling Units, 2009 – Resolution A.1023(26) - Chapter 6 - Machinery and Electrical Installations in Hazardous Areas for All Types of Units - 6.5 Emergency conditions due to drilling operations

6.5 Emergency conditions due to drilling operations

  6.5.1 In view of exceptional conditions in which the explosion hazard may extend outside the above-mentioned zones, special arrangements should be provided to facilitate the selective disconnection or shutdown of:

  • .1 ventilation systems, except fans necessary for supplying combustion air to prime movers for the production of electrical power;

  • .2 main generator prime movers, including the ventilation systems for these;

  • .3 emergency generator prime movers.

  6.5.2 In the case of units using dynamic positioning systems disconnection or shutdown of machinery and equipment necessary for maintaining the operability of the dynamic positioning system should be based on a shutdown logic system designed to preserve the capability to maintain operational control over the integrity of the well and station keeping capability. Shutdown of generators and related power supply equipment needed for the operation of the dynamic positioning system should be divided into independent groups to allow response to gas detection alarms while maintaining position keeping.

  6.5.3 Disconnection or shutdown should be possible from at least two strategic locations, one of which should be outside hazardous areas.

  6.5.4 Shutdown systems that are provided to comply with paragraph 6.5.1 should be so designed that the risk of unintentional stoppages caused by malfunction in a shutdown system and the risk of inadvertent operation of a shutdown are minimized.

  6.5.5 Equipment which is located in spaces other than enclosed spaces and which is capable of operation after shutdown as given in paragraph 6.5.1 should be suitable for installation in zone 2 locations. Such equipment which is located in enclosed spaces should be suitable for its intended application to the satisfaction of the Administration. At least the following facilities should be operable after an emergency shutdown:

  • .1 emergency lighting under paragraphs 5.4.6.1.1 to 5.4.6.1.4 for half an hour;

  • .2 blow-out preventer control system;

  • .3 general alarm system;

  • .4 public address system; and

  • .5 battery-supplied radiocommunication installations.

Parent topic: Chapter 6 - Machinery and Electrical Installations in Hazardous Areas for All Types of Units
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