GEC Z5670
(Not to be confused with the Z5760, which is a bulkhead fitting.)
Thanks to Davy Warren for sending this. This lantern was removed from column 2 on Cressbrook Walk, Plymouth, in early 2004 and was replaced with a ZX1 on a stub bracket with a Zodion SS9 part night photocell (the Z5670 was controlled by an all-night Venner MSQP time switch.). There was no actual fault with the lantern - it was just removed due to the gradual phasing out of time switches in the Plymouth area.
The Z5670 in as-removed condition. It is similar to the Z5698U but is probably actually the earlier version of the Z5713. The 'mushroom' appearance of this lantern was quite a popular design in the past. Unfortunately, the grub screws have jammed solid and so will need drilling out, the holes for them then needing rethreading and then new grub screws have to be found.
The canopy is hinged but it can be removed if the two screws holding the hinge pin in position can be removed. The refractor can move up and down on the two support rods, depending on the type of focussing required.
This is not the moon, but is actually the canopy from above!
With the canopy removed, the lantern appears to be much narrower.
I had to remove the right hand rod in order to take the bowl securing rim off - the nut had jammed on the thread and had to be heated off! (There should be four nuts when the lantern is fully assembled - two below and two above the rim.) The lampholder support is also adjustable, and can be raised or lowered depending on the lamp type. When the lantern was removed, it ran a SON lamp, but originally may have been mercury, and so it will be converted back by the fitting of a 3BC lampholder.
The bowl is yellowed, but the top third of it is clearer than the other two thirds. Notice the amount of spots of dirt on the bowl - some Exodus required I think!
Yes, that's better!
I then removed everything from the base casting in preparation for the work I was to do with it.
Looking at the underside of the casting, the marks from a hammer can be seen. This was the only way that the lantern could be removed from the column!
New grub screws were fitted to the base casting on the 31st July 2004. By this time, I had also attacked the base casting with some Nitromors to try and remove the old paint. As can be seen, this was only partly successful, and so the casting will be bead blasted and then re-sprayed.
And here is the casting and top rim after this work was completed (6th August 2004). They are both now extremely smooth.
The casting from the side. The paint must be quite thick - the GEC logo is not as legible as it was with the old paint.
I then reassembled and rewired the lantern - it's ready to be powered up now.
The canopy was repainted both inside and out - so it's nice and shiny too!
The lantern was first powered up on Monday, 9th August 2004, using the Vennerette time switch and 125w gear from the Sturgess School footpath (see the Backboards page for details.), however the time switch was faulty, and so I had to manually switch the lantern on/off.
Here is the lantern after being powered up. Although the light looks quite yellow/green here, it gives off a good mercury colour in real life, despite the yellowed bowl.
With the flash switched on, there looks to be less of the green-ness in the light than before.
Although the lantern had been restored, the heavily yellowed bowl still showed that the lantern was old. But nothing could be done about this, I thought. However, I then noticed that a couple of WRTL lanterns, the PTBTS and PTCHS, had a bowl that looked almost identical to the one used in the Z5670. I sent an email to the company asking for prices of these bowls, but received no reply, so more or less believed that it would be the yellowed bowl, or nothing, for the lantern...
That was until I received an email from a company called Marwood Electrical, who are a major lighting supplier in the UK. It soon became clear to me that they dealt with a lot of WRTL equipment, so I again asked if there was a possibility of obtaining a new bowl for the Z5670. One was found, and to cut a long story short, was delivered on Monday, 24th January 2005. I fitted it to the Z5670 and was quite taken aback at how much I could now see inside the lantern!
This is how the bowl arrived - covered in Bubblewrap!
Removing the Bubblewrap revealed a brand new, clear and very shiny new bowl.
I fitted the new bowl, and then stood back in amazement - I couldn't believe that this is what the lantern would have (more or less) looked like when new! By now, the time switch had been repaired and was working properly again.
Now when the lantern is powered up, the lantern is much brighter!
With the camera's colour balance set to 'fluorescent', the mercury lamp looked a lot whiter.