GEC Z9481

Lantern acquired in March 2005.

This lantern was on a Stanton 7 concrete column in the parking area of the Markeaton St allotments (just a stone's throw away from the park where the 2600 used to be installed, incidentally), and was removed when the column was decommissioned. The lantern was switched from the cell on a column on the main road, and so the base of the column did not contain any other switching device. I do not know of any other Z9481s in the City area; however, Walton Road in Drakelow was home to several.

Although this lantern is one of the SRL 35's ancestors (with that having begun life as the GEC Z9580), it bears little resemblance to the Siemens lantern.

There are a few very small pieces of concrete around the top-entry thread on the canopy, but no rust patches from the bracket, so the lantern was probably easily removed.

The bowl was in an excellent condition, with the only real damage being a slight crack by one of the hinges. What is odd is that when the Z9454 range was brought out in place of the Z9450, the bowl was changed, in order that it had refractors running along the bottom; however, the clear-bottomed bowl was retained for the Z9480 range. Etched in the bowl's rim is the part code 'Z6764', along with '6266 with hinges' (I assume that a separate type existed where the bowl slotted into a support ring). Another detail is '5863', with the '63' surrounded by a circle - a possible indicator of when the lantern was made.

Opening the bowl reveals that everything inside is also in good condition. The gasket is loose in places but this can be stuck down again. The spring is missing from the lamp support, but a new one shouldn't be too hard to find.

The gear for the Z9481 comprises a GEC Z1619G ballast, Z1757X 6.5 F capacitor (dated to 1979) and a more modern Parmar ignitor. As all of these components are likely to be newer than the lantern is, I suspect that the original gear must have been renewed in around 1980. The supply cable to the lantern may have been replaced at this point too, as the surviving length of twin-and-earth cable seen within the lantern in the above image appeared newer than the lantern would be.

The lantern was restored on the 27th May 2005 - the canopy was repainted (both inside and out), the bowl cleaned up and the gasket was washed and then reattached.

With the canopy repainted, the position where the side-entry spigot on the alternative model is more apparent.

The gasket had shrunk slightly in the wash, and so I used two small pieces of bubblewrap to plug the space.

I was surprised that the gasket material was bright green after cleaning.

I also made a new spring for the lamp support - this was done by wrapping a length of earth wire from some old Twin & Earth cable around a pen, and securing it to the frame. This setup was only temporary, however, as fellow collector Davy Warren sourced a replacement lamp support spring later.

The lantern was mounted to an AC Ford AC184 wall bracket on Tuesday, 9th August 2005. Notice the gear in the background - the wiring was about half completed when I took this photograph.

The wiring completed, I switched the lantern on and all was well. The ballast is quite noisy whilst in use, however they always were.

Lantern 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
232 0.24 42 56 49.7 0.74 41.20 6.20 18%

WRTL 2600 | Thorn Gamma 5




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