Obstacle marking and lighting
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 13 - Helicopter Facilities1 - 13.5 Visual aids - Obstacle marking and lighting

Obstacle marking and lighting

  13.5.23 Fixed obstacles and permanent equipment, such as crane booms or the legs of self-elevating units, which may present a hazard to helicopters, should be readily visible from the air during daylight. If a paint scheme is necessary to enhance identification by day, alternate black and white, black and yellow, or red and white bands are recommended, not less than 0.5 m nor more than 6 m wide.

  13.5.24 Omnidirectional red lights of at least 10 cd intensity should be fitted at suitable locations to provide the helicopter pilot with visual information on objects which may present a hazard to helicopters and on the proximity and height of objects which are higher than the landing area and which are close to it or to the limited obstacle sector boundary. Such lighting should comply with the following:

  • .1 Objects which are more than 15 m higher than the landing area should be fitted with intermediate red lights of the same intensity spaced at 10 m intervals down to the level of the landing area (except where such lights would be obscured by other objects).

  • .2 Structures such as flare booms and towers may be illuminated by floodlights as an alternative to fitting the intermediate red lights, provided that such lights should be arranged such that they will illuminate the whole of the structure and not interfere with the helicopter pilot’s night vision.

  • .3 On self-elevating units the leg(s) nearest the helideck may be illuminated by floodlights as an alternative to fitting the intermediate red lights, provided that such lights should be arranged such that they will not interfere with the helicopter pilot’s night vision.

  • .4 Alternative equivalent technologies to highlight dominant obstacles in the vicinity of the helideck may be utilized in accordance with the recommendations of the ICAO.

  13.5.25 An omnidirectional red light of intensity 25 to 200 cd should be fitted to the highest point of the unit and, in the case of self-elevating units, as near as practicable to the highest point of each leg. Where this is not practicable (e.g., flare towers) the light should be fitted as near to the extremity as possible.


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