Atlas Alpha 10

Lantern acquired in March 2006.

This, and the following lantern came from Mike Docherty, though this lantern has very much come home as it was originally located in Derbyshire. The lantern would have originally used a 100 W SOX lamp - this rating is what eventually became the 90 W lamp. The Alpha 10 is a rare lantern these days - the fact that it was meant for cut-off light distribution restricted its use somewhat. A small numbers of Alpha 10s existed in Hatton (this example may once have been used there itself), though there were a couple of others on a bridge over the A52 at Borrowash until mid-2005.

The Alpha 10 is very shallow due to it being cut-off; however, it makes up for this in width, in order to help spread the light along the road.


The cut-off cover is made from acrylic, and is very clean. Unfortunately, it has a slight crack in it near the lampholder, but this is hardly noticeable.


Opening the cover makes very little difference to the photograph! I am surprised that there are not more of these lanterns about - just look at the simplicity of it!


A limited restoration was undertaken on the lantern in May 2018. The cover, reflector and lampholder were removed and much of the lantern was wiped clean. One of the two grub screws used in securing the lantern to a bracket had seized and had to be drilled out, and the subsequent hole re-threaded.


With the lampholder support bracket removed, I was interested to see that there were two positions that could accommodate it - I assume that the inner position could be used in the event of the lantern being required to accommodate a (shorter) 55 W / 60 W lamp - functionality that Atlas/Thorn also employed with their Alpha 1 lantern.


Officially, however, the lantern could only accommodate a 100 W SOX lamp.


The lantern was attached to a wall bracket on Friday, 18th May 2018, in a position that (deliberately) situated it below its big brother, the gigantic Atlas Alpha 8.


A 90 W control gear set was wired up remotely from the lantern, and switched on.


The wide canopy surrounding the lamp made for a rather spectacular effect.


The cut-off distribution worked well, and the lantern's positioning alongside the Alpha 9 (on the left) demonstrated how very different two lanterns employing the same wattage could be!


Lamp switch-on 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
240.4 0.6 121 144 49.8 0.82 118.28 28.28 31%

Philips SGS 203 | GEC ZD10606




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