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gec z5565np

Genre: Closed dome refractor lantern

The closed dome refractor lantern appeared in the 1920s, a result of the burgeoning scientific approach to street lighting. By using a refractor dome positioned around the upper parts of a symmetrical point light source, beams of light could be fashioned and positioned to illuminate the road surface. The flux emitted in the lower hemisphere of the light source was uncontrolled, producing a circular pool of light below the lantern. In this way, the road surface for some distance and the environs around the lantern were illuminated.

Most manufacturers made a range of Group A and Group B lanterns lanterns utilising this optical system. The GEC sold their range as the Wembley lighting system and Wembley lanterns were extremely popular.

This lantern design changed little during the next seventy years, although the glassware, refractor assembly, lamp holder and lantern canopy became steadily simpler.

In cases where no precise focusing mechanism was present, the filament of the bulb was either located at the base of the refractor, or at the position marked on the refractor glass (usually indicated by "LC" or "Lamp Centre"). In the case of high-pressure mercury bulbs, the arc tube was positioned in the same place as the filament.

Bowls were initially glass and available in a variety of shapes, either simple 'well-glass' types or more shapely 'acorn' shapes. Some form of diffusion, to soften the effect of the main beams, was available with rimpled glass or semi-opaque opal options. When plastics became available after the Second World War, manufacturers used the new material, and a range of bowls was available in Perspex, acyrlic, polycarbonate and Diakon.

The use of pendant style lanterns with dome refractors started to diminish in the 1960s as horizontal lamp lanterns (such as SOX and SON) using reflectors became more popular.

Name: GEC Z5565NP
Date: Early 1950s - Mid 1960s
Dimensions: Length: 31¼", Width: 9½", Height: 11"
Light Distibution: Non Cut-Off (BSCP 1004:1952)
Lamp: 60-200W GLS
Bracket: GEC Z2311 Pole Bracket


The Z5565 series was the result of a rationalization by the GEC in the early 1950s to consolidate the previous smaller Wembley (Z5540 series) and Oxford (Z5543 series) side road lanterns.

A wide canopy allowed an extensive lamp focusing system to be incorporated, allowing the lantern to take, and correctly focus, a wide range of tungsten, mercury and sodium lamps.

The lantern could also accommodate a series of different dome refractors and bowls, supporting both the Wembley, Oxford and Difractor lighting systems.

The company made these lanterns for over a decade before redesigning and further simplifying the canopy which resulted in the Z 5580 and Z 5590 ranges.

Note: Documentation for this range has yet to surface. I'm happy to predict that the Z5565 has a BC lampholder, the Z 5566 a 3BC lampholder and the Z 5567 an ES lampholder. But the various letters which specify the dome refractor and bowl combinations are not yet known. An educated guess, based on subsequent lanterns, suggests this lantern is a Z5565NP.


The lanterns were popular being installed throughout the UK. However, they were not as numerous as the Z 5580 and Z 5590 series which succeeded them.


The lantern's large sculptured canopy, large 'GEC Made In England' logo cast into the canopy, and its range of GEC designed refractors and bowls makes this range easy to identify. Care needs to be taken however, as the earlier Z 5543 series supports a similar canopy, but there are subtle differences.

Optical System

The lantern supports the: Wembley lighting system which uses a simple dome refractor in association with a plain or diffusing bowl; the Oxford lighting system for tungsten filament lamps which uses a symmetric dome refractor and supporting bowl refractor; and the Difractor lighting system for the longer discharge lamps which utilizes just a bowl refractor.

The secondary optical system includes a white-enameled over-reflector. This has 'Street Side' baked into the enamel, which indicates the position of the road for axial and non-axial asymmetrical dome refractors and bowls to be correctly positioned.


The lanterns didn't have gear.

the gec z5565np in my collection

facing profile

This lantern and bracket were originally saved a car enthusiast who wanted an authentic old street light to illuminate the path by his collection of old Rovers. I was given it when the shed and telegraph pole (on which the bracket was bolted) were demolished. It was probably an old parish street light but wasn't typical for Cambridgeshire so probably came from somewhere else.

front profile

The lantern was in extremely good condition. The bowl was still clear, suggesting it was made of the more expensive anti-vandal acrylic which does not discolour and cloud over time. The bowl and canopy profile were typical , but there was no doubting its make, as a large GEC logo was also cast into the side of the canopy.

trailing profile

The lantern had also retained its glass refractor dome which was used to redirect the light emitted above the horizontal into two main beams. The bowl was essentially to protect the lamp and dome refractor from the elements, prevent the accumulation of dirt and improve maintenance.


The wide canopy was extensively grooved and sculptured, a throwback to earlier pre-war designs. Its width was simply a design choice to match the size of the various bowl options, but later versions of the lantern slimmed and simplified it. The bowl ring was secured by a hinge (far side) and a large toggle catch (near side).


The lantern was originally finished in primer and matt-aluminium coloured paint. At some point the whole lantern was painted green, but the lantern was later given a coat of silver coloured paint to restore it to its original appearance. Some of the green is starting to show through where the silver coating is starting to chip away.

pedestrian view

The dome refractor was connected to a steel enameled reflector which acted as a secondary reflector, redirecting some of flux from the lamp down back onto the street and path. The rim of the refractor was marked "GEC Z 6508 60 Made In England". The Z 6508 is a 160° non-axial asymmetrical refractor, so this lantern was used to illuminate a road and not an open area. The "60" designation was the date code for the glassware, indicating that it'd been manufactured in 1960.


All light control was done by the dome refractor, so the bowl was simply used to protect the lamp from the elements and keep it clean. The shape of the plastic bowls was a nod to the old dispersive opal stepped bowls of previous lanterns.

open bowl

With the toggle catch undone, the lamp swings open, and if correctly orientated, the bowl swings to the side of lantern, and not to the back where it could hit the bracket or column. A green enameled "Street Side" on the reflector allows the lantern to be correctly orientated, the refractor engaging with lugs in the reflector, so its correctly orientated with respect to the street.

focusing mechanism

The reflector is fitted on a hinge and can be opened to reveal the focusing mechanism. This comprises a metal spine on which are printed various lamp designations (200W GLS/125W MBF/U, 150W GLS, 80W MBF/U and 100W GLS/75W GLS/60W GLS) and a movable lampholder with a locking wing-nut.

The lantern is focused by moving the lampholder so the window shows the correct lamp wattage and then tightening the wing-nut.

The entire mechanism is quite small and compact and reveals that the width of the canopy was an aesthetic choice only.

the gec z5565np: as aquired

A friend was asked to demolish an old shed in neighbouring village Elmdon in preparation for new building work. "I think it had an old street light on a telegraph pole next to it," he said. "Anyway, I wasn't sure, but I saved it anyway and left it by your back door."

I returned home that evening to find a near mint GEC Z5565NP on a rusting GEC Z2311 Pole Bracket.

The lantern was stripped down and cleaned; the bracket had all its paint removed, was rust treated, then primed and painted.

I later explored Elmdon on Google Streetview and found the lantern. The owner of the property collected old Rovers and his shed, which was in the front garden, was plastered with Rover memorabilia and automobilia. The old street light, on its own telegraph pole, was added to create that 1960s/1970s scene.

The front garden has since been developed and a house stands on the site.

My thanks to Stuart for rescuing this lantern for me.