Rodney

The Rodney Lampworks was a very small operation, the factory being peculiarly situated in between a row of houses on a small crescent. Its precise origin is not known, although it eventually came under the control of Thorn Lighting who retained it for many decades specifically to produce the smaller runs of special types, to avoid interference of production of the main high volume lamps which were made on Thorn's higher speed machinery at its other factories. Following the takeover of Thorn by GE Lighting, the factory was promptly closed with most of its production being transferred to Leicester.

The precise origin of the Rodney lamp works is not known, although its owner, Omega Electric Lamp Works, is cited in the 1969 Competition Commission Report on the Supply of Electric Lamps as having been founded in 1918. An Omega lamp works is also known to have existed in Sheffield, formerly known as Beacon Lamps Ltd, but it is not known whether there is a link between the two sites or perhaps if the Rodey plant may have been a successor to Sheffield. Strangely, the earlier 1951 Competition Commission Report on the Supply of Electric Lamps makes no reference to either of these operations. Rodney is also mentioned in some 1940s lamp manufacturing specifications of the Ponders End Works of BTH as "Factory No. 5", and at that time appears to have been related to BTH.

In 1957, Omega Lamp Works was taken over by Thorn Electrical Industries. Omega had built up a significant market share in cheap single coil lamps for the retail sector, in which Thorn also wanted to increase its presence, and it effectively bought the company including the factory as a way of buying Omega's customers. At that time the production of many of the high volume more standardised lamps was shifted out to Thorn's other factories which had faster and more efficient machinery, however the product portfolio of the Rodney works was very wide, including numerous special lamps having unusual lifetime and electrical ratings. These were required for applications such as incandescent streetlighting, coal mine and railway carriage illumination. It would have represented a great hindrance to the high speed automatic production of Thorn's other factories to be continually interrupted to make very short runs of these specialised types, so the Rodney works was retained for their manufacture.

Later still, once Thorn had upgraded all of its main GLS lines to produce lamps having coiled-coil filaments, all of the single coil types were transferred back to Rodney again. Single coil lamps cannot be made on such high speed equipment as coiled-coil types because of the greater number of filament supports that are required, as well as the more difficult nature of handling the longer filaments.

In 1991, Thorn sold its light sources division to General Electric of America, but the Rodney lampworks was not included in the sale. The factory continued to be onwed by Thorn but since GE Lighting took over the entire sales portfolio of all of Thorn's lamps, the transitionary company GE-Thorn was formed to manage the Rodney lampworks - along with the other factories at Merthyr Tydfil and Preston Kent Street which were in a similar situation.

Just like in the Thorn days, GE faced the same difficulty that the product range of Rodney was so wide that it could not easily transfer those lamps to its own operations - not even to the Hungarian Tungsram company, which it had taken over a few months before Thorn. Many of them were required exclusively for the UK market and in such small volumes that it would not have been economic to produce them overseas. Meanwhile government contracts also meant that their production could not simply be abandoned. As part of GE's plans for consolidating its UK manufacturing, the decision was therefore taken to transfer their production to the GE-Thorn factory at Leicester, and Rodney's production came to an end in July 1993.

Lines R1, R2 and R3, making 60mm, 68mm and 80mm single coil lamps were transferred and continued running at Leicester until 1996, when the old-fashioned single coil lamps they produced finally came to an end. The few remaining customers requiring these special single coil lamps, most notably the city of Derby for its remaining incandescent lamps, and British Rail for its 65V and 85V GLS lamps used in series circuits for the lighting of older railway carriages, were transferred to the Crompton factory at Guiseley.

In 1952 the company developed the "Omega Pluslife" lamp, a range of GLS lamps having a guaranteed life of 2500 hours vs the industry standard rated life of 1000 hours, which achieved considerable success and was manufactured for more than fifty years. Such design would normally result in a significant drop of luminous flux, however Omega attempted to limit that loss by deliberately designing them at the upper end of the wattage limits detailed in the British Standard 161 specification. That stipulates that the maximum individual lamp wattage should not be higher than 104% of the rated value, and Omega instead aimed for the average of its production at 104% of rated watts. Given the normal variation in lamp wattage across all production, some individual lamps could in fact be as high as 106% of rated watts. The consumer was of course not advised of the increase in power consumption and lamps were marketed in the normal ratings of 25, 40, 60, 100 and 150W.

Omega also manufactured two other ranges of long-life lamps. The first was according to the NCB 241/64 specification, and these were made exclusively for the National Coal Board, later British Coal, and also for British Railways. These offered a slightly shorter rated lifetime of 2000 hours and a moderately higher luminous flux than the Pluslife range. Omega as well as its later owners Thorn Lighting tried repeatedly to persuade the NCB and BR to accept its more standard 2500-hour lamp, but without success. The volumes required for these types were, however, sufficiently large that production of the special 2000h rating could be justified.

The third range of long life lamps was made according to the IEC 64A specification which required effectively the same luminous flux, power and 2500h lifetime specifications as the Pluslife range, but having differently sized bulbs. IEC64A lamps were particularly popular in the Nordic countries where Omega's later owners, Thorn Lighting, enjoyed a rather large market share. A high proportion of the electricity generated in that region is provided by hydro-electric sources, with prices considerably lower than other methods of electricity generation. Consequently for this region alone, it was often more economical to accept a less efficient long-life lamp and make some small saving on maintenance costs. For normal power generation methods, a shorter-life higher efficacy 1000-hour lamp was however the most economically viable solution - except in cases where the costs of maintenance are high, such as in coal mine or street lighting, where the longer life lamps were favoured. The longer life lamps also have somewhat thicker filaments than the standard 1000h coiled-coil range, and were preferred in these applications because of their improved shock and vibration resistance.

Consideration was given at some point to manufacturing all of the Omega Pluslife lamps according to the IEC64A specification, but the difference in bulb shape was troublesome for many of Omega's British consumers, particularly for street lighting. The 100W Pluslife lamp in an 68mm diameter bulb with long neck had become something of a standard in older British road lighting installations, and the shorter-neck lamps in smaller 60mm bulbs as detailed in the IEC64A specification gave poor optical results due to their shorter light-centre-length - as well as occasional problems of shattering in in the rain. Omega did eventually bring its Pluslife range in-line with the IEC64A specification, but a special range of 100W lamps in PS-68 and even PS-80 bulbs was continued for sale exclusively to local authorities for street lighting. Right up to the end of the factory's existence these were still produced in ever-dwindling quantities, most notably for the town of Derby which was one of the last to be lit with what had by then become known as the "Derby 100" incandescent lamp.