A look at street lights

Considering this illuminating presence in our lives.

Lamp-posts as part of our lives

Progress comes in different guises but how often do we consider the intangible cost. A beautiful new running track along a nearby beach is bringing residents out for exercise as never seen before. LED lighting in turquoise-coloured lamp-posts punctuate the route; toilets have been erected and ironically, a host of food outlets have also been set up. All of this opposite a row of desirable residences whose owners no longer venture to the sea-shore in solitude. And, no longer can we gaze at stars from a light pollution free beach. We can argue the benefits of the fitness track. We can argue the effect on the value of these residences. While we understand the benefit to the community of the fitness track we ponder when and why street lighting was introduced; its sources of illumination and current types and finish of the posts available.

Imagine your walk or journey home from work or the shops without street lighting. How would you feel? Would your senses be heightened? Would you fear what might be around the corner? If we’re lucky we might have moonlight to guide us or we have headlights from passing cars to illuminate familiar features. Without it our residential and urban areas would take on a different perspective at night.

Security from street lighting

Historically, it would appear that security is the leading justification for street lighting. Crime levels are high in locations where it fails or is sporadic. Electric lighting has been referred to as the ‘efficient policeman’. In modern societies, we think nothing of street lighting outside our houses, in high streets and shopping centres, in car parks, at stations, subways and alleys; to name a few places. It’s there and we’d miss it if it weren’t. By allowing us to see objects and people at night, street lighting offers security and an element of protection.

The history of public lighting

This need to feel safe dates back to about 500 BC. In China, populations near Beijing were able to channel natural volcanic gas emissions via bamboo pipes to lamps in the street. Elsewhere, the ancient Romans used vegetable oil to fuel lamps they hung in front of their homes. Somewhere in the passage of time the innovation wasn’t developed for hundreds of years. In England, the first use of public street light is said to have been introduced in the 15th century when a law was passed requiring all houses to hang lanterns outside at night during winter. No doubt not all alleys and passages could be lit and the necessity to carry a lamp and some form of weapon or paid security, neither of which was a guarantee of safety, continued into the early 19th century in Europe. In many parts of the world today, however, this is still very much a way of life.

Gas street lighting

With the introduction of gas lamps on poles, street lamps, had a mixed reception but for the first time it allowed people to go about their business feeling safer with them than not and crime levels fell.

In the UK some of these Victorian 19th century gas lamps survive with credit for their survival, protection and restoration due to English Heritage. In London, working examples of gas lamps may be seen in the City of Westminster and St James Park amongst a few other places. They are still lit and extinguished manually and daily.

Early gas lit street lighting was hung on poles at a height sufficient to light the passage of hand-pulled carts and horse drawn carriages. With the development of the motor industry and transport infrastructure street lights evolved as well. In residential areas street lighting has seen the lamp post rise to several metres high and cast light downwards for pedestrians to walk and motorists to drive safely.

Street lights powered by electricity

The light from gas lamps was a soft glow effect which was replaced by a harsher and brighter light with the installation of electric lamp posts. Arc lamps and incandescent lamps were used before today’s high pressure sodium lamps were introduced. It’s hard to believe street lights used to be switched on and off manually, one by one, by policemen on the beat until they became automated to turn on and off when natural light achieves certain levels.

What are lamp-posts made of?

The styling, materials and finish of lamp posts has also changed from the traditional decorative cast iron post to the more sleek and elegant; though traditional styles still have their place in design schemes. Some now argue that street lighting could be made ‘smart’ and programmed to turn on when there is movement within their vicinity.

As LED has been introduced so the styling of the lamp post has changed. Artistic structures, often with branch type fixings on slender poles, coupled with neat light housing, provide attractive, fun looking, sometimes colourful and functional street elements.

Compositions of contemporary lamp post include concrete poles pre-stressed with steel cable and an all-weather textured finish. Depending on the location of the lamp posts, the finish needs to resist salt sprays, smog and air borne chemicals including acids and alkalines. A weathering and self-healing steel is designed to not require surface protection and is unaffected by scratches, chips and surface damage.

Aluminium, treated with a protective and non-corrosive powder coating, is also used. Stainless steel is however, more popular due to its inherent strength. A galvanized steel version incorporates a thin zinc layer that protects steel, or iron, from corrosion. Other steel finishes include zinc-rich polyurethane primer and polyuria finishing coat; which is also a graffiti deterrent.

We are fortunate to generally be able to move safely within our western societies thanks to street lighting of one sort or another.