GEC Z8455
Lantern acquired in June 2024.
This lantern was bought from an eBay seller in Leicestershire, who had, in turn, purchased it at a car boot sale some years earlier. Thus, nothing is known of the lantern's history, although it appears to have been out of service for a considerably long time, and its condition has deteriorated from these years of disuse, particularly internally. Production of the Z8455 seems to have been from the early 1960s until the mid-1970s, when the energy crises that marked that decade saw it discontinued - no doubt, the materials used in its construction were also expensive, compared to the cheaper aluminium construction of the similar ZD10807 lantern, and being a 'heritage' lantern, would also have limited appeal outside of Conservation Areas and the like. A small number of Z8455s survive in the area known as Promenade, in Cheltenham, Gloucester, and within Lincoln, however, but they have been converted to take lamps other than their original twin 40 Watt fluorescent configuration, and look to be more modern than this example is.
The lantern measures 39 inches (990 mm) in height, and 19 1/2 inches (495 mm) in width, and weighs 30 lb (13·6 kg). The majority of its construction is brass, with a copper canopy and gunmetal (a copper, tin and zinc alloy) top finial. The base section appears to be cast iron painted bronze. As the rest of the lantern is unpainted, years of exposure to rain and the atmosphere generally have dulled the metal, and also formed a slight verdigris in places.
The access door (the central panel in the image below) uses a Perspex glazing panel with a refractor positioned vertically. The panel on the opposite side of the lantern is the same (but fixed in place). All other glazing is patterned Morocco glass. Notice that the thumbscrew used in securing the access door is missing.
With the lantern rotated, one of the two 2 ft (600 mm) 40 Watt fluorescent lamps is visible through the glass.
All but one of the lower glazing panels is missing, revealing a very rusted internal support spine. The lantern is also bent between the base casting and the lower frame, with one of the frame pieces having detached. Unusually, the lantern is designed to be attached to a 2 3/8 inch (60 mm) diameter spigot, which, although common in Europe, is not prevalent in the UK (especially not at the time when this lantern was made), where a 3 inch (76 mm) spigot is preferred. The base casting has an octagonal exterior, with a grub screw installed on every side. Naturally, all of these are stuck fast!
The one piece of remaining glass from the lower section. I will endeavour to use this as a template to have replacements made.
The spine is 3/4 of an inch in diameter, and is secured within the lantern using a locknut located inside the base casting. This is larger than 11/4 inch (the largest socket size that I have available), but also appears to be jammed.
Opening the door reveals the positioning of the two lamps. Both have a formed sheet of aluminium behind them, to act as a reflector. The reflectors too are corroded heavily.
The two lamps are Sylvania 'Lifeline' products, with both carrying the date code: - ······ / · , which represents January (- ······) 1985 (/ ·). All four end caps are in poor condition from the dampness suffered while the lantern was in storage for its extended period.
The control gear components are visible within the top section of the lantern, where the spine forms an X - there is no additional reflector employed to concentrate the luminous flux downwards.
As acquired, the top finial was seized (surprise, surprise!), and had to be loosened using a pair of Stillsons (a pipe wrench) for additional leverage. Once freed, I applied a coating of lubricating grease to both threads, in order to make future removal easier. Removing the tent part of the canopy allows the gear components to be seen in all of their rusted glory. A ballast and separate Quickstart transformer operate the lamps, while an oval-shaped capacitor provides the necessary Power Factor correction. Two smaller capacitors provide suppression for any Radio-Frequency Interference (RFI) generated by the ballast and transformer. Sadly, the terminal screws to these components have also turned to rust, and in the process, have lost their heads. The fused terminal block for the supply cable has lost the screw for the incoming live wire, requiring this wire to be stuffed into the same terminal as the internal lantern wiring uses. This probably occurred during installation, meaning that the fuse has probably never had any current passed through it from new!
Using a junior hacksaw, I set about slicing through the (seized!) bolts that held the capacitor's clamp together, in the hope of this component carrying a manufacturing date code. Unfortunately, if anything of this nature did exist, corrosion has long since obliterated it.
Surprisingly, the suppression capacitors turned out to provide a likely manufacturing date, when I looked at them closely - these carry the number '0160'; the first week of 1960 would be a reasonable date for their manufacture.
Naturally, the four lampholders, which should be sprung, to allow lamp replacement whilst maintaining a strong contact ordinarily, were also fixed solid. I thought that I might have to smash the lamps if I could not free them (as an absolute last resort), but eventually, using a thin screwdriver, I was able to prise them free. The cap of one disintegrated immediately, and the others didn't look brilliant. Oddly, neither lamp looks to have had much use, and applying a continuity test to the less corroded ends confirms that these electrodes are intact - just a shame that the opposite ends are wrecked! Going on the 1985 manufacturing date mentioned above, if the lantern were removed from service not long after being re-lamped, it had probably lain out of use for nearly 40 years by the time that it entered the Collection (thus, has spent far more of its approximate 64-year-old life disused than in operation) - no wonder that it is in such a state!
I foresee that this lantern could prove to be one of the most challenging, and in all likelihood, expensive, to restore...ever - watch this space!
Thorn Beta 5 × 2 (c.1975 / 1976) | Simplex Solumbra
CLICK HERE TO MAKE A MONETARY DONATION
© 2002 - English Street Lights Online