12RD. Centurion Close, Barnsbury, London Borough of Islington With thanks to 'HCarter' for discovering this Survivor. Located near a footpath leading onto Caledonian Road is a 15 ft (5 m) Concrete Utilities' Estate Minor concrete column fitted with a top-entry Byway bracket and GEC Z9481 lantern, running a 35 Watt SOX (low pressure sodium) lamp. This column seems to have survived an earlier redevelopment scheme, with the road having been known as Ponder Street from 1937, and Cumberland Street prior to that. No other concrete columns remain on this road, and how this example avoided replacement is a mystery, but I am, of course, pleased that it did!

When photographed in January 2025, the lantern was operating in daylight, and appeared to have been doing so for a considerable amount of time - since June 2015 (at least).

The bracket had developed a slight forward lean, but this wasn't a recent change either.

The original flat inspection door had been lost, leading to a curved replacement door being rather crudely inserted into the base compartment instead. I peered into the exposed base through the top curve and observed some relatively modern Philips lamp control gear inside, but was unable to determine if any sort of switching device also existed - the lantern didn't seem to have a photocell fitted.

As the bins still make reference to Ponder Street, this part of the road may still be known as such, despite maps identifying it as Centurion Close, and only the footpath link is Ponder Street.

The characteristic 589 nm wavelength of the low pressure sodium lamp was very much a rarity by the time that these pictures were taken.

The replacement tubular steel columns supporting WRTL 2000 post-tops are visible in the background, when this installation is pictured from the other side.

A black spot had formed on the lamp's external oxide coating, suggesting that some of the sodium vapour had been drawn out of the arc tube through the conductivity of the lamp's barium getter, as well as the oxide film itself, which is susceptible to attack from the released vapour, as has occurred here.

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