The Thorn Alpha 4 was a very common sight on British and Irish roads from the 1960s right through to the 2000s! It was designed purely for SOX lamps and gave off the gold/orange glow that defined so many streets and main roads of the time. The Alpha 4 had a distinctive look and was often found lighting dual carriageways and major routes. They’ve mostly disappeared today but are now one of the classics of British and Irish streetlights.
My town in Ireland used to be covered with these, but they've very swiftly been replaced by HPS/SON and more recently LED fixtures. The last one in my town was recently replaced with an LED.
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