Lantern acquired in March 2006.
Nothing is known about this lantern's history, however it may have been used locally. If so, this must have been a good long while ago as I have never seen a HW-918 in use in this area; including in 'Old Derby' photographs. This example has a prismatic glass bowl, though different plastic options were available as well - including the 'toffee' style polycarbonate; an example of which can be seen here. In fact, this lantern may be the HW-922, as the '918' designation seems to be for lanterns with plastic bowls, although there is no difference between the two types apart from this.
The lantern is very shallow, but is quite a long lantern for a Group 'B' mercury fitting.
The lantern's elliptical shape suggests that it was designed for elliptical lamps as well.
The prismatic glass refractor bowl is surprisingly clean - though sadly it has been bumped at some point and as such a crack has appeared. I do have a spare, however the refractors form a different pattern on this bowl:
Whereas the refractors in the existing bowl 'comb over', the ones on the new bowl merge together, and there are vertical refractors at either end.
The inside of this lantern is probably the most interesting bit - surrounding the lamp is an open glass cylinder. This simply fits between the lampholder and the canopy. Thanks to Wayne for finding out that in the 1960s the cylinders were recommended by manufacturers, in order to prevent the lamp from overheating and exploding. This was obviously found not to happen as later lanterns did not utilise the cylinder.
The lantern was protected by a 6-amp fuse in a Lucy MISL cutout, switched by an all-night Venner MS2SP time switch, and controlled with some GEC gear.
The lantern was prepared for restoration on Sunday, 29th October 2006. I decided that the blackening on the inside of the canopy was a good enough reason for me to get the metalwork sand blasted and then repainted. The photograph below shows the canopy after having all internal components removed.
The various masking tape labels visible are instructions for what I wanted done to each section.
The freshly restored canopy returned on the following Wednesday (1st November). I was very pleased with how it looked!
The finish on the 'exterior' side of the canopy reminded me of the standard finish applied to an WRTL Arc.
The insides also impressed me - though they didn't look right without being fitted with the components!
Whilst the canopy was being restored, I cleaned the porcelain terminal block and lampholder and refreshed the brass screws and terminals by dipping them in vinegar overnight.
The new bowl was fitted, and the lantern was installed on an AC Ford AC 872 wall bracket.
I decided to reuse the glass cylinder and gently positioned this around the new lamp.
The gear and time switch were connected up, and then I switched on:
The cylinder can clearly be seen behind the front part of the bowl.
The refractors on the bowl are very effective at distributing the light.
Lantern warm-up video:
Thorn Beta 8 / AEI Junior Amberline | AC Ford AC 850
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