Low Pressure Sodium (LPS) Lamps

Possibly my favourite style of street lighting - mainly because of the different casing they come in and I have always liked the colour they emitted. As previously mentioned on the index page, all of these lights give off an orange glow at night. Low Pressure Sodium lamps are now only installed for residential purposes and in some tunnels. On arterial roads, they face extinction as they will all eventually be replaced by High Pressure Sodium fixtures in the near future. Please click on the thumbnails to access the full sized image.

LPS #1 (circa 1930's)
Locations: Adelaide only
Rate of Extinction: Extreme
Technical Name: Unknown

	Kensington (2003) - South Australia
	Oakey (2003) - Queensland

The first of the early LPS models. The only working ones I have seen reside in Adelaide. The shape of the casing is unusual - huge cubic area, protecting the small filament in the middle. The bottom photo is the only LPS #1 I have seen outside South Australia, being in Oakey (QLD) however it is missing its filament. These lights were created and installed well before light poles were utilised thus the light fitting will only ever be found from a bracket on a power or stobie pole.

LPS #2 (circa 1940's-1950's) Locations: Adelaide only Rate of Extinction: High
Technical Name: Mazda SOX (90W)

	Kensington (2003) - South Australia
	Darlington (2003) - South Australia

The next of the LPS early models. Casing is made smaller and flares out - obviously the wider exit angle allows more light to be shed onto the road. Again, the only examples I've seen are located in South Australia - again, these lights were installed before individual light poles were used and thus appear only from power or stobie poles.

LPS #3 (circa 1960's-1970's) Locations: Generally South Australia, Wangaratta Weigh Station, Broken Hill Rate of Extinction: High
Technical Name: Thorn Alpha 1 (90W)

	Paringa (2004) - South Australia
	Broken Hill (2003) - New South Wales
	Whyalla (2003) - South Australia

An unusual design with less shading of the filament from the previous two fittings. Light can escape not only downwards but to surrounding region thus these lights appear a little brighter at night. There is a small reflector above the filament preventing light escaping upwards - was a popular model back in the 1960's but soon became redundant which was a shame as the extra light that escaped I thought was a good feature. This design was the earliest model to appear on light poles however I have not photographed any examples at this stage.

LPS #4 (circa 1960's) Locations: Generally South Australia, Cowra, Canowindra, Wagga Wagga, Parkes, Forbes, Newcastle, Narrabri, Toowoomba, Warwick, Stanthorpe, Mudgee, Taree Rate of Extinction: Moderate
Technical Name: Eleco (Phillips) GR100 (90W)

	Canowindra (2003) - New South Wales
	Parkes (2004) - New South Wales
	Cowra (2003) - New South Wales

A more recent model - still a very common fixture - many of these still in use through country NSW and of course SA. The middle photo on the shows a burnt out filament without its outer or inner casing which is rare. The bottom photo demonstrates that this model also occurs on light poles.

LPS #5 (circa 1960's-1980's) Locations: Generally South Australia, Newcastle, Toowoomba Rate of Extinction: Moderate
Technical Name: GEC Z9554 (135W)

	Morphett Vale (2003) - South Australia
	Morphett Vale (2003) - South Australia

The first of the higher wattage low pressure sodium lamps - means that this light has the potential to give off more light than the others previously mentioned and is therefore mostly found around main highways, thoroughfares and busy intersections. Due to the brighter orange emitted, this light is commonly found on light poles (bottom photo) as less lights are required to illuminate a greater area.

LPS #6 (circa 1960's-1980's)
Locations: Generally South Australia, Cowra, Toowoomba, Ipswich, Weipa, Dalby, St George (QLD), Forbes, Wagga Wagga, Newcastle, Taree, Warwick, Orange, Sydney-Newcastle freeway interchanges
Rate of Extinction: Moderate
Technical Name: GEC Z9454 (90W)

	Murray Bridge (2004) - South Australia
	Payneham (2003) - South Australia
	Cowra (2003) - New South Wales
	Ipswich (2003) - Queensland

Probably the most common low sodium light still in existence today. In Adelaide and perhaps SA alone, this would be still the most common style of arterial road street lighting. Quite a few of these remaining in some parts of the NSW and QLD. This style of low sodium was still being manufactured and installed during the mid to late 1980's so many of these light fittings are still relatively new.

LPS #7 (circa 1960's) Locations: Adelaide, Wagga Wagga, Forbes, Parkes, Bowning, Goulburn, Yass, Blayney Rate of Extinction: High
Technical Name: Eleco (Phillips) GR150 (135W)

	Forbes (2004) - New South Wales
	Glenelg (2003) - South Australia
	Goulburn (2003) - New South Wales
	Goulburn (2003) - New South Wales

Bigger brother to Low Sodium #4, as it emits more light due to a larger filament and wattage although is less frequent. The third photo actually contains a 90W filament (instead of 135W), so is actually a cross between LPS #7 and #4.

LPS #8 (circa 1970's - 1980's) Locations: South Australia only Rate of Extinction: Moderate
Technical Name: GEC ?? (135W)

	Port Pirie (2003) - South Australia
	Henley Beach (2003) - South Australia

Another Low Sodium lamp that has the larger filament - this casing is a little wider than Low Sodium #5 and again, these lights are generally found only on larger arterial roads and busy intersections. This design was purposely "cut-off" to minimise glare - typically installed around airports. Another model which is exclusively found on South Australian roads.

LPS #9 (circa 1970's) Locations: Adelaide, Willunga, Robe, Molong, Coonabarabran, Gulgong Rate of Extinction: High
Technical Name: Eleco (Phillips) GR551

	Coonabarabran (2003) - New South Wales
	Molong (2003) - New South Wales
	Toowoomba (2004) - Queensland
	Molong (2003) - New South Wales

Smaller version of LPS #5 actually resembles LPS #4. Rare in numbers as it was a late contender for pole monopolization before the Low Sodium series were phased out. The third photo forms an unusual casing, so far only found in Toowoomba.

LPS #10 (circa 1975) Locations: Generally South Australia, Narrabri, Newcastle, Queanbeyan, Taree, Goulburn, Yass, Forster, Coolah, Toowoomba, Blayney, Mudgee Rate of Extinction: Moderate
Technical Name: Phillips MA (90W-150W)

	Marion (2004) - South Australia
	Queanbeyan (2003) - New South Wales
	Cowra (2003) - New South Wales
	Coonabarabran (2003) - New South Wales

One of the newest arterial road sodium lamp. It was introduced in the mid 1970's and replaced many of the first LPS lights that had burned for 30 years. While there are plenty of these still on roads today, there would have been more had the High Pressure Sodium lamps not come into existence as early as they did. The more exploring I have done, the more subtle differences of this model are found as they can hold various filaments thus emit various wattages.

LPS #11 (circa 1960's) Locations: Wagga Wagga and Forbes only Rate of Extinction: Extreme
Technical Name: Unknown

Forbes (2003) - New South Wales

Extrememly unusual low pressure sodium casing - Quite a few remaining in Wagga Wagga and a couple in Forbes rendering them rare and almost exotic in design. The design itself is baffling considering all other models have some form of protection or shading.

LPS #12 (circa 1960-70's)
Locations: Adelaide only
Rate of Extinction: Extreme
Technical Name: Unknown

West Beach (2003) - South Australia

Rare LPS fixture that is even hard to find on Adelaide roads. Most of these originally resided on main arterial roads and there were select spots that they were in abundance. The casing is similar to LPS #6, however has an open bottom as they were primarily used for areas around airports to minimise diffusion.

LPS #13 (circa 1950-60's) Locations: Gympie, Toowoomba, Warwick, Stanthorpe, Ipswich Rate of Extinction: High
Technical Name: AEI SOX (90W)

	Ipswich (2003) - Queensland
	Gympie (2003) - Queensland
	Gympie (2003) - Queensland

Another unusual design which has similarities to LPS #7, however native only to south-eastern QLD. Very few of these around, despite being in a LPS friendly zone. The bottom two lights are from Gympie and have since been replaced by High Pressure Sodium lamps.

LPS #14 (circa 1960's)
Locations: Parkes
Rate of Extinction: High
Technical Name: Unknown

Parkes (2003) - New South Wales

Similar to LPS #7, another rare casing holding a larger filament. This is the only one I have seen and was found in Parkes (NSW).