Thorn Alpha 4
This lantern was all ready to be used, however its bowl and clips were required for another job, and so has not been installed anywhere. It has a fair amount of dust and dirt on it from being in the van, but this will wipe off easily. Alpha 4s are often used to replace failed Alpha 1s in Derby, but have also been used on new lighting schemes as well.
This photograph shows the Alpha 4 before I fitted the new bowl and clips. Yes, two clips are visible, but they are not yet glued in place. You heard me right; the clips have to be glued to the lantern!
A close up of the gear shows that the ballast is not a Thorn one, but a Transtar. I was surprised to see the capacitor fitted in the shoe, but the rest of the gear fitted in the lamp compartment. This lantern is narrower than the MA 90, and so there is not enough space to fit all the gear together!
The label is located at the very front of the lantern and uses all kinds of coding, but the most important is the 'QA4' bit, as this is the Alpha 4 identification code.
Gluing the clips didn't take long, but the glue took a while to set. I put the bags below each clip 'area' in case of drips, but luckily there weren't any. The photocell socket has been wired out, but there is no cover over it.
When the glue dried, I fitted the bowl. Although all the clips are all the same, they have to be fitted differently to both sides of the bowl. One side opens completely, whereas the other acts as a hinge.
The lantern was fitted to an AC Ford AC872 wall bracket and powered up on Sunday, 28th August 2005.
A cutoff bowl is also available for the Alpha 4, though it isn't as common as the regular semi-cutoff one.
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