Local Thorn Alpha 4s

 The Alpha 4 first appeared here in the late 1970s-early 1980s and was still being installed in 2005. It was popular in both its 90 W and 135 W SOX versions; with both the gear-in-base and gear-in-head versions of the latter. It has been used on new installations and for replacements of older lanterns. Its popularity kept the Philips MA range in second-place, which must be something of an achievement!

This 90 W example used to be able to be seen on St Helen's Street opposite BBC Radio Derby. In fact, this column (35180) was frequently mentioned by presenters on the station as it is one of the few things that could be seen from the studio windows! The gym behind the column has since been demolished.

This 90 W example in Willington is mounted at the unusual height of 6 m.

This Alpha 4 replaced a damaged Alpha 1 around the 5th November 2002.

Another Alpha 4 replacement below; this example in Duffield would have replaced a defective Alpha 9 lantern in the early 2000s. The 1970s' Stewart & Lloyd column is leaning slightly; perhaps as a result of being struck by a vehicle in the past (this could be why the lantern required replacement).


This now-removed 135 W remotely-geared Alpha 4 on the A6 Duffield Road in Allestree has been fitted with the bowl from a GEC Z9554 - from the ground, this actually appears to be quite a good fit!

A little further up the A6, more remotely-geared 135 W Alpha 4s can be seen; these examples are in Milford.


The detector for a Royce Thompson ER4N two-part photocell can be seen protruding from the lantern's canopy.


The bowl is missing from this example.


This close-up reveals that the lantern's rear panel is also missing.


Another nearby example was dayburning at the time of photographing.


This 135 W gear-in-head Alpha 4 on Derby's old Nottingham Rd is on a column, which would have supported an Atlas Alpha 8 originally.


This soon-to-be-removed 135 W example is on Rykneld Rd. From the angle that the photograph was taken, it appears that the Holophane Syracuse Medium (QSM) is mounted post-top to the existing column. This is not the case - a new column has been erected for the new lantern!

The QSM was itself later replaced due to the Derby Street Lighting PFI - click here for details.

An altogether less common variant of the Alpha 4 that is seen locally is the type with a cutoff bowl. These appeared on roads that required re-routing as a direct result of the A50 Derby Southern Bypass' construction in the mid-1990s. The examples below are to be found on Willington Road and Heath Lane in Findern; there are both 90 and 135 W types to be seen.


The shallower bowl type is clearly visible here.


A number of overhead High Voltage transmission lines pass by this area; necessitating the use of Abacus base-hinged columns for the lighting positions that are within the proximity zones of the lines.


This particular example was dayburning at the time of photographing in April 2015; the Zodion SS9-DLS part-night photocell having failed. This does, however, allow for the cutoff distribution to be appreciated.


Underside view of the lantern.


The bowl on another example was missing completely; judging by the rusting present on the ballast, this has probably been the case for a while.


This 135 W example is also attached to a base-hinged column.


This close-up view reveals that the lantern's canopy fibres are beginning to shed.


This example is fitted to a 10 m Stainton tapered octagonal column.


Again, the shallowness of the bowl becomes apparent when seen alongside the deeper gear shoe.






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