Illumination and Lighting

A satisfactory level of lighting should be available to enable the bridge personnel to complete such tasks as maintenance, chart, and office work satisfactorily, both at sea and in port, daytime and night-time (IMO, 2000). The following bulleted list and table contain an overview of important lighting points (IMO, 2000): [19]

Essential information will need to be identified as such. Cross-system consistency will be required.

SCC layout	Information	The layout needs to	SCC design needs to
and design	provision to each	allow supervision	proceed in an
	operating position	and teamwork.	integrated manner.
	will need to be		Proving that this aim
	fully considered.		has been met will require user-centred design through the life cycle.

Source: ATOMOS.

Some system Layout needs Equipment location needs Alarm messages need integration to provide to avoid causing to support the bridge may be good access distraction. If it is not team and pilot in required to to part of SCC operations it location and ensure that information should not be on the visibility. operational and to allow bridge. If it is relevant, status is defined, assessed, and indicated. teamworking. then it needs to be appropriately located.

FIGURE 9.1 Manoeuvring a ship close to an oil rig cannot be done by one person. (Draw­ing by E. Jacobson after a photo. With permission.)

• The lighting system should enable the bridge personnel to adjust the light­ing in brightness and direction as required in different areas of the bridge and by the needs of individual devices. Table 9.3 lists the recommended general illumination levels and colours.

• A light-dimming capability should be provided.

• Utmost care should be taken to avoid glare and stray image reflections in the bridge environment.

• Lighting sources should be designed and located to avoid creating glare from working and display surfaces.

• Reflection in windows of devices, instruments, consoles, and other reflec­tive enclosures should be avoided.

• Devices should be designed and fitted to minimise glare, reflection, or obscuration by strong light.

Related to lighting is the choice of colours for interior surfaces. For the interior, unsaturated colours should be chosen that give a calm overall impression and mini­mise reflectance. Bright colours should not be used. Dark or mid-green colours are recommended; alternatively blue or brown may be used. In spite of these guidelines, a very common complaint is about the lack of dimming (Lutzhoft et al., 2007). The bright light destroys night vision, disturbs the keeping of a safe lookout, and distracts attention (see Figure 9.2).

TABLE 9.3

General illumination for the Bridge

Colour/lllumination

Red or filtered white, continuously variable from 0 to 20 lux White, continuously variable from 0 to at least 300 lux Red or filtered white, continuously variable from 0 to 20 lux Red spotlights, continuously variable from 0 to 20 lux White floodlight, continuously variable from 0 to 1000 lux Filtered white floodlight or spotlights, continuously variable from 0 to 20 lux

Source: IMO (2000).

Not only modern displays cause dimming trouble. Many disturbing points of light are visible on many bridges, and the problem mainly stems from the amount of different manufacturers providing equipment, and the lack of integrated or system design thinking. Homemade dimmers abound, some more innovative than others (see Figure 9.3).