When people think about lighting a container terminal, the conversation usually centres on lux levels, mast heights, glare and energy use. One area that often gets far less attention is optics. More specifically, asymmetric optics.
They play a much bigger role than most realise.
Optics shape and direct the light from each individual LED. They control how the beam spreads, the direction it travels in and how intense it is. Without the right optics, even the most efficient LED will waste light in the wrong places.
In a port environment, that can be an expensive and operationally challenging issue.
Asymmetric optics are designed to push light in a controlled, directional pattern rather than in a neat, symmetrical cone. Instead of distributing light equally in all directions, they send more of it forward or sideways. This is exactly what is needed on high masts in ports, where the aim is to illuminate large working areas without lighting the sky or the back of the pole.
They help solve some of the most common challenges in port lighting.
Symmetric optics often spill considerable light backwards or into areas that do not need illuminating. Asymmetric optics push the light forward, directly onto container lanes, trailer routes, RTG paths and quay edges.
This allows designers to use fewer luminaires, avoid excess overlap and prevent the familiar issue of over-lighting one part of the yard while another remains too dark.
Poor uniformity creates shadows, bright spots and visual distraction. For terminal operators and crane drivers, that can become a real safety risk. Asymmetric optics help deliver a more even spread of light across the working plane, supporting safer operations during night shifts and in low-visibility conditions.
Glare is a well-known problem in terminal environments. It affects crane operators, truck drivers and staff working at height. Asymmetric optics limit upward and backward light, reducing glare without compromising performance.
Keeping the light on the site also helps avoid spill into nearby neighbourhoods or waterways, which supports environmental targets and reduces ecological disruption.
Many ports now specify zero upward light output ratio (ULOR = 0%). Asymmetric optics help designers meet these requirements without relying on bulky shields or sacrificing lighting quality.
Take a 35 metre high mast lighting a container yard. With symmetric optics, you usually need several fittings aimed at awkward angles to achieve acceptable coverage, and glare and spill are still hard to avoid.
Switch to asymmetric floodlights and the picture changes. Each luminaire is engineered to cast light in a specific direction and shape. Coverage improves across the full yard, from the front apron to the far container rows, while keeping the array tidy at the top of the mast. No glare, no dark patches and no wasted energy.
Every terminal has its own layout quirks. Some have narrow reefer corridors, irregular yards or curved crane tracks. Asymmetric optics give designers the flexibility to fine-tune each mast to match these constraints.
Long-throw optics can cover distant yard sections, while wide-angle side optics can illuminate adjacent stacks, all from one pole. This level of precision is one of the major advantages of modern LED floodlighting.
Choosing floodlights based on wattage or lumens alone will only get you so far. Optics are what determine where that light goes and how useful it is once it gets there.
The right asymmetric optics make a lighting installation more effective, safer to operate and far more efficient.
If you would like to explore how asymmetric optics can improve your terminal or want a tailored lighting design for your site, our team is ready to help. Get in touch.