SOX lamps in the UK and overseas

Left: An American Electric SRX-55 (55W SOX) lantern. This is rare in America but is typical of the sort of lamp found in areas in the USA where SOX installations were made. (reproduced with permission of James Sweet)

So where are the best areas in the UK for finding SOX lanterns?

It seems that Wales is a good area, particularly north and south (mid-Wales has a higher concentration of mercury lamps). For example, Neath Port Talbot is estimated at 90% SOX, and the figure is probably similar in the Wrexham area. If you are a fan of Thorn Alpha 1s (and these lamps do seem to have practically their very own fan club), Abergele apparently is the place to go. I myself would recommend Flintshire for having a good range of old models of SOX lanterns, with many other areas having somewhat newer models. Also, it is worth looking for older lamps in less affluent areas as it seems that councils are less reluctant to spend money in new streetlighting in areas where there might be vandalism!

Liverpool and Manchester city centres are also good SOX areas: Liverpool uses Thorn Beta 5s and Philips XGS104s on side roads and the Philips SRS (formerly MA 50s and MA 90s). An estimated 95% of side roads & 60% main roads are SOX (ref: Colin Grimes)

Edinburgh is apparently an excellent place to find SOX lamps: home to Phosco P107s, Thorn Alpha 1s, Beta 5s (side- and top-entry), top-entry GEC9454s (mostly mounted on CU pendant columns), Philips MAs/MIs, plus numerous GEC turtles, Eleco GRs and HW747s. There are also some Relite Hyperion ‘C’s to be found, which have apparently been giving good service since their installation in the early 1970s. Although some lamps are now being replaced with non-SOX alternatives, lantern replacement in Edinburgh isn't quite on the same scale as it is in other cities. (ref: Steven Oliver)

On the other hand, London is almost entirely non-SOX. Metal halide lamps are very popular there as new installations. And in Lancashire, the area where I come from, there has been a massive reduction in the number of SOX lights since around 2001.

Some areas are still installing new SOX lanterns: as mentioned in this book, Thorn, Philips, CU Phosco and WRTL are manufacturers who still make them. Wrexham, Flintshire and Newport are three Welsh counties continuing to install SOX; there are probably others also. The future of SOX lanterns in general will be covered later on.

There are also many SOX lanterns overseas, with some markets very buoyant and other new ones emerging. Belgium and Holland, for example, use SOX (there is a Philips factory in Holland, and possibly one in Belgium); there is an interest in low-pressure sodium there because of the technological development in which they were involved in the late 1970s and early 1980s. In parts of Holland, many mercury lanterns were converted to use SOX instead. However, overall numbers of SOX are now declining in Holland. SOX is far less common in Germany, and is apparently banned from use in residential areas in Denmark because of their lack of colour rendering. (ref: Sjef Jansen, Philips Lighting)

Japan and Korea also use some Philips SOX lighting for tunnels and roads as they are impressed with the quality. (ref: Allan Court, Philips Lighting)

There is also now an interest in SOX by the Chinese. James Hooker of Sylvania in Belgium was recently approached by the authorities in Beijing who requested that he assist them in setting up local production of some six million pieces a year — which would quadruple world production of this lamp! There are apparently some difficulties regarding the supply of glass for these additional SOX tubes, but I myself certainly hope that China’s request can be met. In China there are severe energy shortages, and they see SOX as being the way out of this difficulty. However there are very large import taxes imposed on anything brought into China, so they need local production. (ref: James Hooker)

In many parts of the USA, SOX lanterns are very rare (Americans refer to SOX lanterns as LPS — low-pressure sodium). Apparently there were some test installations in the late 1970s, but the public reaction was very negative, and so most of these have since been removed; however LPS is widespread in Arizona, partly because of the observatories there, used by astronomers who prefer SOX/LPS as it is easier to filter out the light when they are surveying the skies. There is also some LPS in Northern California although apparently some of these installations are also starting to disappear. At one time Southern California also had some extensive installations but these have now all gone, although a few LPS lamps exist in Los Angeles, and more exist in San Diego. Other small pockets of LPS lamps seem to exist elsewhere in the USA. The Rite-Aide chain of stores, which exists all over the USA, uses some 35W lamps for security. As another example, there are some Philips MA-60 installations in Illinois.

My American correspondent suspects that the reason that SOX/LPS lighting was rejected for street and road lighting in many areas is the poor or improper application of the technology by people who didn't understand it well enough, causing the strengths to be under utilized and the weaknesses to be made much more glaring. It seems that the Americans have rejected diesel engines in cars for similar reasons. LPS lights were installed in town centre areas and car parks, two places where colour rendering is more important; some were even placed indoors in warehouses!

In the USA it's not uncommon for long stretches of highway outside of cities etc. to not be lighted at all, so there was not such a need for highly energy-efficient lighting for those sorts of areas.

SOX lighting is however more common in Australia, having been used quite extensively. Here it is also referred to as LPS. However, in Australia also, low-pressure sodium lamps are being phased out and replaced with high-pressure sodium varieties. It is interesting to learn however that most Australian LPS streetlights are the same as in the UK because Philips, Thorn, GEC, Eleco, REVO etc. had suppliers there, as Australia used to be part of the British Empire. There are many photos of Australian streetlights in my book, courtesy of Michael Greenslade. (ref: Michael Greenslade, Colin Grimes, Sjef Jansen)

The information for the UK in this section was correct as at 2004/05. (It's a difficult area in which to find up-to-date information!)

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