REVO/Relite/Simplex 'Diadem' 80w/125w MBF Lanterns. Originally designed and produced by REVO of Tipton, these remote-geared side-entry lanterns proved popular with many local authorities and rural district councils for use on minor roads and side streets in Britain. In areas such as rural Staffordshire, the Diadem was used extensively to extend and improve existing mercury installations during the 1970's. But the Diadem also found favour in cities like Birmingham, where hundreds of the type where put to use as replacements for outdated and damaged fittings on the City's network of minor roads; and these still exist in numbers to this day.

The Diadem was at the height of its popularity during the 1970's, and saw a long production run that began in the late 1960's with REVO, and ended in the 1980's under the ‘Simplex Lighting’ banner. This was brought about by the fall in demand for mercury lighting and remote-geared lanterns in general, and because Simplex Lighting (once part of the Tube Investments Group) was absorbed in to the WRTL group of companies, where the Diadem would have duplicated contemporary product lines. Although many examples the Diadem can still be found, especially in the West Midlands, the type is now in rapid decline.

Made from cast-aluminium, the more aesthetically pleasing Diadem shared the same type of lozenge-shaped prismatic bowl as its bigger brother, the 'Diadem-Major', which was the geared version of the lantern. Access to the lamp is identical for both lanterns, and is made by releasing the toggle-action side catch and allowing the bowl to hinge downward on its side-mounted hinge. There is no dedicated reflector plate within either type of lantern; instead, the inside of the canopy is pained white. Access to the spigot receptor and electrical connector block is gained with the bowl in the opened position.

Earlier versions of the lantern used prismatic glass bowls, but these were superseded by prismatic plastic look-a-likes; unfortunately, the plastic versions tend to 'yellow' over time due to the UV rays emitted from the mercury lamps. The hinge that's moulded into the side of the plastic bowl is another weakness, being easily broken if forced. It's understood that replacement plastic bowls for these lanterns were still available from WRTL in 2005.

There are two Diadems in the collection. The first example came from rural Staffordshire in 2003 and ran a 80w MBFU lamp; it has no photocell switching device fitted to it, so was either group switched or worked from a time-switch. The lantern is in very good condition and came attached to its concrete bracket, which it will be removed from. Like most surviving Diadems, the plastic bowl has yellowed, but a replacement has already been sourced.

The second Diadem came from the City of Birmingham, where the type is still in widespread use. Again, this lantern is a 'Simplex' 80-watt MBF example, but sports a NEMA socket for one-part photocell for automatic switching. The lantern was acquired still attached to its No7 bracket (so-called because of its resemblance to a number 7) and is in very good condition, although its bowl has slightly yellowed. Both lanterns have been placed in storage until time allows for their renovation.

The ex-Birmingham Simplex Diadem 80-watt MBF lantern is seen still attached to its REVO 'No7' bracket.

A Diadem burning an 80-watt MBF/U lamp at night, Wolverhampton.

Simplex Diadem 80-watt lantern on AC Ford bracket in Seisdon, Staffordshire