This is the largest Design Clinic I have ever done. Container parks often measure several hundred metres in each direction. Although the illumination level required may be fairly low, you still need efficient, high output floodlights to deliver a safe working environment. This Design Clinic shows better ways of illuminating a large area compared with older, conventional methods.
A standard container is approximately 2.5m high and 6m or 12m long. Whilst the length may not be important, the height is. Containers can sometimes be stacked four units high, which is about 10m. Unless the floodlights are much higher, this can cause dark shadows on the roadways and between the containers.
For this reason, SLL Lighting Guide 06 recommends that for stock yards and heavily obstructed areas, the ‘throw’ distance should be no more than two to three times the height of the column. Thus, the higher the mast, the further you can space them apart and the fewer you need. A high mast also reduces the length of dark shadows near the containers.
In terms of illumination level, recommendations can be found in EN 12464 Part 2 which deals with outdoor work spaces. The main recommendation is an average horizontal illuminance of 20 lx with 25 per cent uniformity. But note that this recommendation refers to storage areas; higher uniformity and illumination may be required for the actual roads and circulation routes.
Container parks are usually located beside transport hubs such docks, railways and airports so it’s likely that there may be other criteria related to outdoor lighting and signalling. It is impossible to show a complete container park on screen and the images represent an area of approximately 150m x 100m. Figures given in the Tech Spec are representative of the whole area.
This is the best option and uses 25m masts with the Galileo floodlight. This is a really adaptable luminaire with a huge range of beam spreads and light output from 10,000 lm to almost 50,000 lm. There are optics for streetlighting as well as general area lighting.
The Galileo will operate in ambient temperatures from -40C to +50C and it’s good to see on their data sheet that Kingfisher give correction factors for the lumen output across the temperature range.
On the layout shown in the renderings, we have used six Galileo with a wide angle asymmetric lens. These are mounted at equal angles radially.
The 25m height means that shadows between the containers are minimised. It also means that you can space the masts at long distances apart. In our layout, they are at 110m x 65m centres and we still achieve good uniformity.
Another big advantage of LEDs for this type of scheme is that they can be dimmed. I know of a dockyard which dims the lighting to 25% for security. When the ships arrive, the lighting is boosted to full output for loading and unloading the containers. This ability to have a wide range of dimming is not something you can do with HID lamps
Tech spec A
- Luminaires24 No, 6 per mast, Galileo LED
- Light sourceBanks of LEDs
- Optical controlSpecular aluminium reflector
- ArrangementSix per 25m mast
- Average illuminance on roadways
- >40 lxElectrical load per luminaire
- ProsFewest lighting positions, lowest electrical load
High levels at 16m
Sometimes, you can’t use a high mast for environmental reasons. The height may intrude on the daytime and night-time appearance of the surrounding area.
In this option, we have used 16m columns. Again, we could have used a lower wattage Galileo. Instead, we have used a high performance Scorpius floodlight with a 1kW metal halide lamp. This is a really punchy floodlight which will also accept a 2kW metal halide and 1kW hps.
An advantage of this unit over many other floodlights is that there is a range of hoods for various aiming angles (55°, 60° and 65°) that blocks any upward light. In effect, it becomes a flat glass lantern that is aimable.
Due to the lower mounting height we need an extra column on the long sides to achieve good uniformity and minimise shadows. The Scorpius floodlights are aimed parallel to the roadway.
Tech spec B
- Luminaires Scorpius
- Light source12 No 1kW Metal halide 110,000 lm
- Optical controlA combination of wide beam diffuse and specularArrangementAs shownAverage illuminance on roadways40 lux
- Electrical load per luminaire1kW
- ProsWhere you want metal halide
This is how we used to do things! As mentioned, with large areas you need high output light sources in order to minimise the number of lighting positions. Apart from specialist 2kW metal halide sports lamps, the 1kW high-pressure sodium has the greatest light output at around 130,000 lm.
Mind you, it’s worth bearing in mind that some 1kW metal halide lamps can give you over 100,000 lm and that has the advantage of white light and good colour rendering.
Apart from the colour, the disadvantage of the hps lamp is its long arc tube. In effect, it means that in an asymmetric floodlight, you can only control the beam in one axis. When designing a scheme using this lamp don’t simply look at the lumens and LOR. You need to consider where the light is actually going.
The uniformity from this unit is poor such that the value of the average illuminance does not have any real meaning.
Tech spec C
- Luminaires 12 No A N Other floodlight
- Light source High pressure sodium 130,000 lm
- Optical controlHammered aluminium
- ArrangementAs shown
- Average illuminance
- Not enough uniformity to be meaningfulElectrical load per luminaire1kWProsIt used to be a good solution but not anymore