GEC Z8526 250w/400w MBF/SON Lantern. Also known as a 'Turtle' (because the large pressed aluminium canopy is shaped a little like a turtle shell), this large wattage fitting was one of a range of these types of lantern offered by GEC for main road lighting from the 1960's up until the 1980's. Designed to give better light distribution from the larger elliptical MBF(and later SON) lamps, these lanterns saw  widespread use throughout the UK in the 1960's and 1970's. GEC stated that these lanterns should be used with 250w lamps when mounted on 10 metre high columns, but 400w lamps should be employed on 12 metre high columns.

In the West Midlands, Birmingham City Council (a loyal GEC customer) was one of the biggest takers of these lanterns, where they were used in numbers throughout the City in the 1970's to replace ageing 1950's GEC 'Clearmain' lanterns. In the East Midlands, Mansfield was a stronghold for these types of GEC lanterns, but they also employed similar types of lanterns made by Thorn and Eleco. Although other manufacturers made similar 'Turtle' type lanterns, the only real rival to the GEC lanterns was the Atlas/Thorn Alpha-3, which was probably more popular.

Eventually, lighting technology moved on with the advent of the tubed High Pressure Sodium lamp, and lantern design changed to accommodate the new technology, with the emphasis on smaller lanterns with exacting optics for improved lighting distribution and efficiency. By the 1980's the 'Turtle' lantern was phased out of production by manufacturers.

Although declining in numbers, many examples of these large GEC lanterns can be seen in Birmingham and in Mansfield, as well as many other cities around the UK.

The Z8526 in profile. All GEC 'Turtles' are easily recognisable by the deep, flat upright fronts to the canopy, which is quite different to the tapered front of its rival, the Thorn Alpha-3. The car keys show this to be a big lantern, but with its pressed aluminium canopy and having no internal control-gear; it is in fact very lightweight. This example has been fitted with a two-part photocell, which can be seen sticking out of the top of the canopy. Also note the position of the side-mounted bowl release spring-clip, which again is in a different position to the Alpha-3.

This Z8526 has a frosted 'Diakon' bowl with large white spot to distribute the light, but the clear moulded 'Diakon' bowl was more common. Earlier models still employed the white spot, but had a clear plastic bowl with deep 'ribs' moulded into the bottom of the bowl to help distribute the light.

With the bowl opened; we can see into the Z8526's large pressed aluminium canopy. There is nothing complicated about these GEC 'Turtle' lanterns, which are very basic in their design and layout. 'Ribbing' has been incorporated into the pressed canopy to help refract the light from the large 400w HPS lamp. There is the facility to focus the lamp, as the lampholder is on a long adjustable arm, which retracts into the slot on the underside of the die-cast spigot mounting when the lamp is pulled back in the canopy.

The Z8526's bowl hinges from the front of the canopy, and when shut is secured by two clips at the back of the canopy. This is the opposite way around to its rival, the Thorn Alpha-3, which has its bowl hinged from the rear of the canopy and is secured towards the front end.

Similar to the example held in the collection, this Z8526 is one of several used for lighting the platform of a railway station near Grimesthorpe in Sheffield. Picture taken in June 2006.

Here's a later Z8526 lantern with the anodised finish, rather than the grey painted finish of the lantern in the collection. This 250w SON lantern is pictured in Mansfield, Nottingham in June 2006.