IALA has created a recommendation for the correct marking of man-made offshore structures, including oil & gas platforms to aid to vessels navigation.
Each of the platforms shall be marked as a single unit, a block or field, which simplifies the marking process.
MAIN & SECONDARY LIGHT(S)
• Morse letter “U” every 15 secs
• Light colour white visible in any direction
• Intensity range 10 nm
• Vertical divergence 2.5º
• Constructed and fixed as to ensure that at least one light is visible upon approaching the structure from any direction.
SUBSIDIARY LIGHTS
• Flashing red light
• Morse letter “U” every 15 secs
• Intensity range 3 nm
• They shall be located at the horizontal ends of the structure and at interconnecting bridges
ID PANELS
• Visible in all directions
• Black letters or numbers 1m high on a yellow background.
These are the main aids to navigation, in addition to which ATON may be included:
MAIN & SECONDARY FOG SIGNALS
• Autonomy 96h for a power source independent
• Morse letter “U” every 30 secs
• Sound range 2 nm in any direction (MAIN)
• Minimum sound range 1/2 nm in any direction (SECONDARY)
• A visibility detector will typically be used
RACON
• Frequency range*
– X band: 9,300 – 9,500 MHz
– S band: 2,900 – 3,100 MHz.
• Broadcasting uniformity: ±2 dB in X+S bands over 360° (horizontal).*
• Vertical divergence: ±3 dB in bands X+S / 15° (vertical).*
* ITU-R M.824-4 standard
In the following drawing we can see how to place the aids to navigation on an offshore platform:
