My Collection: Thorn Gamma 9

With thanks to Lichfield Council for giving me permission to save this lantern, and collector AgentHalogen_87 for helping me obtain it. This lantern is the prize of my collection, and probably the rarest asset in it. I had vowed to rescue it since I knew of its existence, and the fact it had been disconnected from mains supply and abandoned for two decades, meant it was essentially sitting and waiting for its demise at the hands of vandalism. Although it took over one year to get formal permission to rescue it, it was well worth the wait! I would also like to thank a family member and support worker for helping me get this lantern painted. To complete it, all it will now need is a new bowl. That may sound like an easy last step, but finding even a used one in better condition than this will be a massive challenge!

The lid of the lantern is held on via an aluminium cap, which can be unscrewed and removed in its entirety.

Unlike the Gamma 6, the mounting apparatus in these is recessed into the lantern itself, and the grub-screws are located inside. The cover is held together at the base by a length of insulation tape but despite this, it is complete.

Unscrewing the cap mentioned before allows the inside of the lantern to be accessed. The lanterns hat is quite a bit smaller than the Gamma 6s, but bears a similar design.

Inside the lantern is a relatively-rare 160W self-ballasted mercury lamp. These were not an option with the Gamma 9, so this example was likely GLS originally, before, on the 13th November 1998, a self-ballast mercury lamp was installed. This is the shortest version of the Gamma 9, which was not advertised for SOX, but a SOX lamp 26W-35W can fit with ease. There was the known presence of an AC Ford box on the bridge which would've housed the cut-out. These self-ballasted mercury lamps can get very, very hot, so despite me switching it on once, I won't be running it in this lantern due to fears of damaging the cover. I will likely install a SOX or GLS lamp instead. With the lid and cover removed, the Gamma 9's simple structure is obvious. Essentially, this version of the Gamma 9 is just a tube of acrylic with a lamp inside.

The bowl has ridges on the inside which act as refractors.

An exact date is present on the lamp's base, as well as a signature. I do genuinely wonder if this lamp has ever worked in service, but I'd guess it hasn't, or didn't for very long.

The original sticker inside is heavily faded, and very crispy. Great care was taken when cleaning the lantern as to not damage the sticker anymore, and you can see that I decided to keep the original sticker in the end. I did manage to reconstruct this sticker, and a reproduced sticker was supplied by Mike Barford.

The Gamma 9 lit with it's 160W self-ballasted mercury lamp.

As a bonus, here is the lantern running a 35W SOX lamp. This version of the Gamma 9 was never sold for SOX, but a 35W SOX (or 26W SOX-E) lamp could fit.