Lighting installed in crew staircases on a cruise vessel must be designed to provide a combination of functionality and safety yet still match the overall design. Lighting in staircases is often underestimated. The function of staircases is not only to provide connections between the different decks of a cruise vessel, but they must also function as main escape routes in case of emergencies.
Different areas on a ship require special demands on the lighting
One of the most important factors to consider when selecting lighting for crew staircases is 24-hour runtime, as the lighting must operate reliably at all times in seldom daylight conditions.
Staircases are major public areas on a cruise vessel and so have very specific requirements on the lighting installed there. The design of staircase lights is important and should harmonise with the overall interior design of other crew areas of the ship. There is rarely any daylight in a crew staircase, which means that light fittings must fulfill the requirements of illumination. 24-hour operation calls for long life light fixtures, low power consumption and low or zero maintenance. In case of emergencies, the lights should also ensure a safe passage through the staircase and guide the crew to safety.
To ensure safety on-board, the crew must be able to locate emergency exits in complete darkness throughout the whole of the cruise ship. As a result of the high demands placed on the quality and durability of its products, the Glamox Group operates modern assessment and testing laboratories in Norway and Germany for the simulation of a wide variety of environmental conditions, including ship staircases.
Important factors when working with lighting solutions for crew staircases:
- Restricted space (low ceiling heights).
- Mechanical design/impact resistance.
- Emergency lighting (low location lighting) and escape route signs.
- Design and lighting comfort.
- No maintenance and reduced power consumption (high energy efficiency)
Crew staircases are often narrow and have restricted space, both in terms of ceiling heights and widths. Nevertheless, staircases have a critical function to perform in terms of moving people up and down the decks of the ship in a safe manner. Daylight is seldom available and so illumination must be provided by the light fittings on a continuous 24-hour cycle. Multi-level stairs or open stair designs require a wall installation of luminaires or the use of LED strips in the steps of staircases.
Low ceiling heights in staircases require low surface mounted or recessed luminaires that are designed to fit different ceiling thicknesses, which can vary between 0.6mm and 50mm. Fire classifications of ceilings must also be taken into account in order to avoid extra fire protection inside ceilings. Glamox recommends the use of dedicated downlights for B15 approved ceilings or surface mounted fixtures if possible. All plastic parts should be flame-retardant materials to prevent fire and toxic gases from spreading. The European standard, IEC 60092, requires that light fittings installed in staircases should be designed for ambient temperatures of 45°C. As vibration can create disturbing noise levels from the luminaires, it is also important to choose marine-approved lighting products that are designed to prevent excess noise (i.e. vibration-resistant). Loose internal wiring due to vibration is dangerous and can cause short-circuits. Therefore, the luminaires should be designed according to the relevant marine standards. To avoid lengthy installation times and to reduce maintenance costs, Glamox recommends the use of quick connectors. Dust protection should also be considered, as this can be important during the ship construction/fitting phase in order to prevent dirt from getting inside the luminaires, as well as later during normal ship operations to prevent the ingress of dust and insects to the light fittings.
Emergency lighting (low location lighting) and escape route signs
In the case of a mains power failure, emergency/back-up systems are required to ensure that power is provided at all times to the light fixtures. Emergency systems can be designed in two ways, either as centralised UPS (Uninterruptible Power Supply) or as a decentralised system with integral batteries in each luminaire.
Providing light in an emergency situation is essential for the safe passage and guidance of people around the cruise ship. Escape route lighting (low location lighting) is a method of communicating information to people by using light signs, such as exits, escape routes, staircase lighting, etc.
Design and lighting comfort
An adequate Kelvin factor ensures a good balance between the light output and comfort of crewmembers, which results in a safe and functional area. With no daylight in a staircase, the colour-rendering index (CRI) factor should be above 80 in order to provide good quality light that is visible to the human eye. Glare is an important factor in a corridor, as people travel underneath the light fittings, which are installed at short intervals, and so do not wish to be blinded by the glare as they walk by. The goal of staircase lighting designs should always be to ensure a low uniform glare ratio (UGR) and homogenous light distribution. Glamox luminaires provide features such as trim rings, décors, diffusers and unique reflector designs to limit this glare. Lighting designs can be optimised by using light calculation programs such as Optiwin® and by using high quality luminaires that can limit the effects of shadowing and glare. Flexible light distribution can be provided using adjustable luminaires combined with wall-mounted light fittings.
No maintenance and reduced power consumption
Maintenance-free, easy installation and various mounting options ensure flexibility and time savings, primarily because some lights may be located in areas that are difficult to reach or often with no access at all. The luminaires should consume as little energy as possible in order to reduce the size of power generators, to save energy and to reduce pollution/emissions. Therefore, LED lighting is recommended. LED luminaires are virtually maintenance-free, which means that cruise vessels with LED lighting will have lower operating costs compared to vessels with conventional luminaires. In addition, the reduced power consumption of LED lighting onboard has a positive impact on the cruise vessel’s Air Conditioning system, as less heat is emitted from the lighting, which means less AC power is needed and fuel consumption is reduced. The initial investment of the LED installation may be higher than a traditional lighting installation, but the reduced energy consumption and lower maintenance costs of LED lighting means that this price difference will be quickly recouped and payback on the investment is recovered quickly.
All lighting products in crew staircases should be designed in accordance with marine standards and regulations.