Genre: Enclosed Horizontal Traverse High Pressure Sodium Lantern
As soon as the low pressure sodium lamp (LPS) was developed, the race was on to develop a version which would run at high pressure (HPS).
The research was stimulated by the prospect of the spectral broadening of the light emitted from such a bulb and
the improved colour rendering which would result. However the development was hampered by the lack of a translucent material which
could withstand the chemical attack of sodium vapour at extremely high temperatures and pressures.
It wasn’t until the early 1960s that General Electric (GE) cracked the problems,
closely followed by the GEC and Philips. A prototype high pressure sodium lamp was
exhibited at the APLE's annual conference in 1963, but it wasn’t until 1966 that the GEC erected an experimental installation
along East Lane, Wembley (which, incidentally, also saw the first experimental medium-pressure mercury installation over thirty years before).
The first commercial installation in the UK was erected along the Southend ring road, but it was the City Of London who gained the most
recognition by beginning a radial upgrading of all their lighting to high pressure sodium in 1967. As the early HPS bulbs were designed
to be retrofitted into existing mercury installations, the lanterns chosen by the City Of London were slightly modified versions of
existing mercury lanterns.
The first true HPS lanterns (designed from scratch with the new light source in mind) appeared in the late 1960s and early 1970s. All
these lanterns utilised a cross-over design: whilst this was an adaption of existing mercury lanterns, it also moved the lamp up into
the lantern’s canopy (where it could not be directly viewed by drivers, thus minimalising the glare) and allowed designs to cater for
both cut-off and semi-cut-off.
Wider adoption of high pressure sodium was stalled by the energy crisis, as it couldn’t match the efficiency of its low pressure sodium brother.
Councils, believing in the simple maximum lumens per watt paradigm, replaced existing tungsten, mercury and fluorescent schemes by
low pressure sodium. So it wasn’t until the 1990s that HPS started appearing in greater quantities.
With its efficiency between high pressure mercury and low pressure sodium, HPS became even more attractive when LPS was finally exorcised
from the British Standards of street lighting (as it didn't provide an adequate colour rendering). However, it didn't remain as first choice for
new and replacement lighting schemes for long. Renewed interest in fluorescent (from compact fluorescent sources), the emergence of affordable
metal halide and the possible introduction of LED have all questioned the automatic selection of high pressure sodium for schemes.
Therefore by the end of the first decade of the new century, high pressure sodium’s position as the natural choice for street lighting
was coming under pressure.
Name: Industria Vectra 265122.603
Date: Circa Mid 1980s -
Dimensions: Length: 75cm, Width: 32cm, Height: 26cm
Light Distibution: Conforms with BS 5489-1 / EN 13201.
Lamp: 150W SON-T.
The Vectra was the main street lighting workhorse of the Dutch based
Industria group, initially designed for use on main roads and motorways. As a second-generation
high-pressure sodium lamp, its reflector was multi-facetted, thus improving light distribution and performance.
Various sizes of lantern were produced with the smallest intended for motorway slip-roads (100W SON-T) through to the
largest (400W SON-T) which was intended for motorway lighting. A smaller version of the lantern was also introduced
which was used for subsidiary roads and residential areas and could take the smaller 70W SON-T lamp.
Its main competitors during this period were the GEC Z8600 range and the
Thorn Alpha 8.
The lantern was also sold through Whitecroft in the UK throughout the 1980s and 1990s. After
Industria and Whitecroft merged in the 2000s, the newly formed
Whitecroft Road And Tunnel Lighting, continued with the Vectra line where it remained their
main general purpose high-pressure sodium-lantern for road lighting.
It was eventually discontinued when it was replaced by the Arc.
It was a popular lantern and could be found installed throughout the country. Some examples do look rather the worst for
wear now: the GRP canopy attracts lichens and moss and some of the bowls tend to yellow.
The Vectra was easily identified thanks to its angular chunky modular design and two-tone colour scheme.
Other lanterns from the period were becoming more streamlined so the Vectra’s sharp edges made it stand out from its competitors.
The optical system was developed around a multi-facetted one-piece pot reflector. The characteristics of the top
of the beam, referred to as Low Threshold Increment (LTI) or Medium Threshold Increment (MTI) were changed by
altering the position of the lamp. A full-cut off distribution required the lantern to be fitted with a flat-glass bowl.
The gear is housed in its own gear compartment. This has a lower IP rating than the lamp compartment and access is
achieved by unclipping the back plastic cover.
The gear is mounted on a removable gear tray at the back of the lantern.
Three components are usually screwed in position: the main lamp choke, a power correction capacitor and the ignitor.
The Industria Vectra In My Collection
This Industria Vectra came from Cambridge. It was probably installed in the early 2000s as part
of a junction relighting scheme and later removed in 2016 when the Cambridgeshire-Northamptonshire PFI replaced the
The bowl is secured by a stainless steel clip mounted at the front of the lantern. Given the smaller area of
the bowl (as compared with the earlier larger HPMV and SON lanterns), the clip and gasket are able to seal the lamp
compartment to IP 66.
The profile of the lantern is easily identifiable thanks to its chunky linear lines and two-tone colouring of the
various compartments of the main body. The plastic used for the bowls is high quality and doesn’t seem to suffer
from discolouration and/or cracking which was a problem with other manufacturers' products.
The black plastic gear compartment was designed to be easily accessible. Therefore the black rear covering was
easily removable by pushing two spring clips.
The top of the canopy shows the modular construction. It also reveals an Industria logo which was cast into
the top of the gear compartment covering.
The lantern was available in various sizes and this was the mid-sized option. It could take a 150W SON lamp.
A special facetted refractor, two types of bowl profile and various lamp mounting positions could be used to alter the
The lantern could also be mounted either side entry or post-top. A hinged cover in the base of
the gear compartment could be moved to provide either mounting option.
The entire optical system within the lamp compartment can be seen with the bowl open. The lamp position could be
moved higher into the reflector optic, providing either a Low Threshold Increment (LTI) or Medium Threshold Increment
(MTI) distribution. Full cutoff could be achieved by fitting the lantern with a flat-glass bowl.
The gear compartment was separate, sealed to IP 54 and opened by pushing two spring clips. It was not entirely
separate and was still connected to the main body of the lantern by a plastic tie and the wiring
for the NEMA photocell socket.
The entire gear compartment could be removed by pressing another spring clip and unplugging various
connectors. The main ballast (a Parmar HSZ163222B3) was mounted on one side of the
folded sheet-metal plate and could drive a 150W SON lamp.
The power correction capacitor and ignitor were mounted on the other side of the plate. These included a
DNA 20uF capacitor (dated 2002) and a Tridonic ZRM 6-ES/B T1 Ignitor for 100-400W SON.
industria vectra as aquired
This lantern originally stood on the intersection of Coldhams Lane and Cromwell Road, Cambridge. (It's the one on the left in
the picture). Vectras
were only used sparingly in the city and were used for lighting junction upgrades. This was the case here where
the Vectras were installed in the 2000s when the road junction was remodelled.
It was removed in 2016 as part of the Cambridgeshire-Northamptonshire PFI scheme.