High Pressure Sodium Lamps

The High Pressure Sodium lamps are the favoured light type in Australia to be utilised on arterial roads. Since their introduction in the late 1980's, these lights have spread extremely quickly. High Pressure Sodium lights give off a very bright pinky-orange colour. Their casing varies only slightly, making this light family rather predictable and boring. Nevertheless, these lights have revolutionised street lighting - they are extremely bright, aren't as prone to bugs, have a longer life, warm up quickly and generally takes far less of them to effectively light a road than the other, older street lights. Additionally, because of their pinky-orange colour, at night objects aren't illuminated in a monochrome style - actual colours of objects can be seen more easily.

Click on the thumbnails below for the full sized image.

HPS #1 (circa 1988-onwards)
Locations: Everywhere
Rate of Extinction: Extremely Low

	Wilcannia (2003) - New South Wales
	Canberra (2003) - Australian Capital Territory
	Queanbeyan (2003) - New South Wales
	Canberra (2003) - Australian Capital Territory

This was the first High Pressure Sodium lamp to be utilised in Australia. Introduced in the late 1980's, this style and casing is still in production and used when older lights are to be replaced. While the casing is commonly used for the High Pressure Sodium filament, it can disguise a Mercury Vapour light (white) globe. The top photo has a protective cage around the light, usually installed in regions of high crime.

The bottom photo is the newer style of High Pressure #1 without the glass casing underneath. Many of the new lights now have a flat cover instead of the ones shown above to cut down on diffusion and enable the light to be directed more at the road. When approaching these lights, it appears they are not even on until you are close to them. This principle has long been used around airports.

HPS #2 (circa 1990-onwards) Locations: Everywhere Rate of Extinction: Extremely Low

	Canberra (2003) - Australian Capital Territory
	Canberra (2003) - Australian Capital Territory
	Morphett Vale (2004) - South Australia

Perhaps the most common High Pressure Sodium lamp. Introduced later than the first style, however the amount of these has significantly increased in more recent times. Since Victoria's widespread street light changeover, this style of High Pressure lamp has become the favoured replacement. Similarly for Adelaide, however only when a Low Pressure Sodium lamp has burnt out. Like HPS #1, this casing can also hold a Mercury Vapour globe though uncommon.

The top photo is the newer flat covered version, also to cut down on diffusion

HPS #3 (circa 1990's)
Locations: NSW and ACT only
Rate of Extinction: Low

	Canberra (2003) - Australian Capital Territory
	Canberra (2003) - Australian Capital Territory

Similar design to Mercury #7, however this style generally has only a High Pressure Sodium filament installed inside the cover.

HPS #4 (circa 1990's-onwards) Locations: Generally QLD (highest proportion in Gladstone), Canberra, Kangaroo Valley Rate of Extinction: Low

	Canberra (2003) - Australian Capital Territory
	Ipswich (2003) - Queensland

Uncommon casing for High Pressure Sodium lamps to reside in. While they are prominent in Gladstone, QLD - they are extremely rare elsewhere, even in the places listed above. While the casing appears unusual, the characteristics are the same as HPS #1 & #2. The photo on the right is the newer style with the flat cover to again minimise light diffusion.

HPS #5 (circa 1970-1980's)
Locations: Wagga Wagga and Cootamundra
Rate of Extinction: Medium

Wagga Wagga (2002) - New South Wales

Very rare fixture - so rare that I have only found them suspended and not on poles. I havent seen this species anywhere but in south-west NSW.