The ‘best point of passage’ may be indicated by a white light or lights located under the span and exhibiting a safe water mark character. If there is more than one navigable channel under the bridge, the same system should be used for each channel. The ‘best point of passage’ will be determined by the competent authority, taking into account all relevant factors, such as:
- Maximum available headroom
- Water depth under the bridge, particularly where it is not uniform
- Protection of the bridge piers and other obstructions
- The need to have one-way or two-way traffic
Red or green flashing navigation lights may be used to mark the navigable limits of the channel in accordance with the IALA Maritime Buoyage System. Bridge spans other than those marked by red and green lateral — such as spans to be used by very small craft — may be indicated by special yellow lights as prescribed in the system.
If navigation is possible in the full passage span, the lights should be located on the bridge piers. If navigation is possible only in a part of the span, the lights should be located under the span or on buoys and beacons placed in the water to indicate the limits of the navigable channel.
The power supply is often a critical consideration when specifying navigation lights to mark a bridge. If mains power is readily available, then this is usually the easiest solution. However, the lights may sometimes be sited some distance from a mains supply. In this case, a solar power supply needs to be considered.
Self-contained solar lights are relatively simple to deploy, but the structure of the bridge will often mean the lights are not in direct sunlight. If this is the case, then standalone lights with a separate solar power supply mounted in direct sunlight will be required.
For additional information, please contact Hydrosphere to discuss your requirements.