GEC Z9539

Lantern acquired in May 2010.

This lantern was installed on an abandoned Stanton 10F concrete column on a road that was once within the perimeter of the Pastures Hospital site in Mickleover. Following the closure of the hospital in the early 1990s, many of the identical installations around the site fell into disrepair, however, the lighting on this particular road remained in use, owing to the small number of business that occupied the lower section of the road. The most notable business was the Grangecraft Garden Centre; this itself closed briefly in 2005, but re-opened as the Mickleover Garden Centre a few months later. The garden centre closed again in early November 2008, and this time, it didn't re-open. The site was subsequently cleared and currently (as of May 2010) is being prepared for a new use. Whilst the lighting along the road hadn't worked since approximately 2003, the columns still carried a live supply until April/May 2010, when the cable was disconnected and removed from the former hospital-related building at the end of the road that had provided the isolation and switching point for these lights.

The first couple of photographs show the lantern, as it appeared in March 2004; when the garden centre was still open.

Fast-forward to May 2010, and the lantern is now no longer installed. It was removed just under a week before these pictures were taken. The column door was also missing by then.

The lanterns and brackets were missing from all but one of the installations visible from the locked gate. I suspect that the remaining bracket was left alone due to it being in a poorer state of repair than the others were.

The lantern comprises an aluminium canopy and (discoloured) polycarbonate refractor bowl.


This lantern is not fitted with a photocell, as the lighting was group-switched from dedicated control points. When removed, the canopy was (almost literally) caked in bird dirt. A few minutes under the jet of a pressure washer soon sorted this problem out!


A small drainage hole had been drilled in the centre of the bowl.


This Z9539 had not been in use for several years prior to its removal; damp has been able to enter the lantern (helped by the lack of a gasket), leading to corrosion setting in on the gear tray. In addition, the bowl on this example probably hadn't been opened in around sixteen years - the OSRAM lamp seen here dates to April 1994; the last time any maintenance was undertaken on this lantern! Prior to the lantern's pressure-washing, the inside of the canopy was awash with numerous dead spiders and woodlice - even after cleaning, the lantern still carries a revolting earthy smell...just think yourselves lucky that this smell cannot be conveyed on the pages of a website - it was rather horrific!


The gear tray is held in place with a single screw (two would have been fitted originally); however, this was found to be seized, and had to be drilled out before access could be gained to the gear.


The gear is in terrible condition - both the ballast and capacitor are severely corroded. Notice that the capacitor is positioned at an angle. This, combined with unused slots on the gear trays suggest that these lanterns were originally designed for the 'bottle-shaped' capacitors, as seen on the aluminium-canopied Z9532, but by the mid-1970s, when this lantern was produced, cylindrical capacitors were fitted instead. This wouldn't be altered until the Z953# range of lanterns was modified towards the end of that decade, in order to cater for the then-new, and more efficient Z1616P ballasts with 6.5 μF-rated capacitors.


A few days after the above pictures were taken, I decided to free the ballast from the gear tray, just to see whether the bolts were seized or not. After much effort, I was successful in freeing them, however, the ballast still could not be moved. I was able to lever it away from the gear tray using a screwdriver; doing so produced the sound usually heard when two items that have been glued together are being separated. The reason behind this was soon all too clear - it appears that the internal oil within the ballast had leaked and then congealed between the ballast and the gear tray. This would have contributed to the strength of the unpleasant smell mentioned above. Owing to the age of these components, I was rather concerned that this oil might be a harmful Polychlorinated Biphenyl (PCB). The gear tray will therefore be discarded in its entirety. The canopy will be retained.


Restoration of the lantern commenced towards the end of 2018. Despite the earlier comments, the gear tray was not scrapped in the end, but it did need sand blasting and a complete repaint before it could be re-used in the lantern. This was completed by the 16th November.


The leaked ballast gunge disappeared completely after this work; however, the years of disuse, and subsequent corrosion to the steel gear tray left a slightly pitted appearance to the finish in parts.


The canopy followed in February 2019. Along with being bead blasted, this was repainted in a light hammered grey finish, in order to replicate the original appearance of the aluminium.


The inside was repainted in the same way.


The two components were reunited temporarily, and a far clearer bowl fitted. The lantern was still an empty shell at this stage; the next step was to fit new wiring, and (would you believe) a new ballast.


By the 23rd February, the lantern was re-assembled properly. It had also had a new top-entry wall bracket fitted at this time.


Amazingly, despite the years of dereliction, coupled with its ballast failing, the 1994 lamp worked when tested, so was reunited with its lantern. Two new fixing holes are visible on the gear tray; these support the replacement Philips electronic 55 Watt SOX ballast, which fits perfectly in the lantern.


A new sealing gasket was fitted around the inside of the lantern rim, and new stainless steel fixings for securing the lampholder and gear tray were installed.


With new wiring connected, the whole assembly was attached to the wall.


The 25-year-old lamp produced a gorgeous crimson colour when powered up.


The bowl refractors are designed to start just after the lamp's electrodes; the surrounding polycarbonate being clear.


This view demonstrates the refractor distribution against the wall.


The lamp support is plainly visible in the centre of the lantern.


The lantern's distribution causes a small amount of light to be visible above the horizontal.


The working lamp provided a streak of colour amongst the industrial grey and silver.


The top-entry bracket comprises a 1′′ BSP right-angled bend fitted with a ′′ BSP reducer, and finally, a male-male coupler.


I never expected a lantern that looked so sorry for itself upon acquisition to be emitting the distinctive low pressure sodium glow ever again - how wrong I was!


Frontal view.


Lamp warm-up video:

Testing with my energy monitoring device revealed the following results:

Test Voltage (V) Current being drawn at full power (A) Measured wattage (W) Apparent Power (VA) Frequency (Hz) Power Factor True Power (W) Difference to rated wattage Percentage Difference
243.2 0.28 64 68 49.9 0.98 66.73 11.73 21%

Philips FGS 103 | Philips 'Mini Iridium' BGS 451


Lanterns in the Z953# range in collection

Z9531 Z9532 (aluminium) Z9532 (GRP) (1) Z9532 (GRP) (2) Z9536 (aluminium) Z9536 (GRP) Z9538 Z9539




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