ELECO HW-852 (Ware Mk. 3)

Lantern acquired in April 2021.

This lantern was removed from the junction of Water and Barn Streets in Lavenham, Suffolk on the 22nd March 2021, and at the time of removal, was the last lantern running a mercury vapour lamp to remain in service in the village; the rest having been replaced with WRTL / Indal / Philips Stela Long LED lanterns, owing to the lower power consumption, as well as the obsolescence of mercury lamps a few years earlier. Indeed, a tubular steel column supporting the same was used as the replacement for this lantern and its wall bracket. With the vast bulk of mercury stock having been replaced during the 1980s in Derbyshire, HW-852s were not a sight to be seen on my own County's roads. Thank you to Suffolk County Council's Street Lighting Department, as well as Lavenham Parish Council, for their assistance in saving the lantern for me.

The installation, as it appeared in July 2020. Even at this time, the writing was on the wall, or rather, the floor, for it, with the proposed new column position sprayed on the paving below.

The zoomed-in view allowed me to confirm that a mercury lamp remained installed; in this case, the lamp was made by Venture.

Much of the wall bracket pipe, along with its (normally) diagonal support bar, remained attached to the lantern. The actual wall mounts were left in place, however, as there was concern that attempting to remove them could cause damage to the brickwork of the (listed) building. The first task was to file down the cut ends of the two pieces of metal, as they were razor-sharp and only too keen to cut my fingers!

The lantern comprises a die-cast aluminium canopy, transparent Perspex bowl, and glass refractor ring. It measures 12 1/16 inches (306 mm) in height (the canopy itself being six inches (152 mm) high) and 9 5/8 inches (244 mm) in diameter.

The ELECO logo is cast into the rear of the lantern canopy, whilst the "Across Road" arrow indicator is cast into the front.

The bowl is supported by an aluminium ring that tucks inside the canopy when secured. Some small holes in the bowl have allowed wasps to congregate inside, which have then become trapped and died inside the lantern.

A single clip secures the ring, with the other side being hinged to the canopy, ensuring that it cannot fall away. Not visible here, but cast into the inside of the canopy are both the HW-852 code, as well as HW-853; this lantern employing the same type of canopy, but fitted with a glass refractor bowl, rather than a transparent bowl and separate refractor ring, as exists here. Two sprung hooks secure the refractor to the lantern body - a notch on the canopy allows a small extrusion on the refractor to locate correctly, ensuring that the correct beam distribution is achieved. A three-pin bayonet lampholder is positioned between the two hooks. The lamp wasn't included, as it was worn out and discarded during removal.

This is the 'side' view of the refractor - the point seen here would be where the majority of the beam was cast, providing symmetrical distribution along the road.

A few cracks exist in the refractor, although I think that they pre-date the lantern's removal.

Moulded into the underside is "E.L.E. Co. LTD ST. ALBANS".

The part number (what appears to be "HW 333") is moulded opposite. Unfortunately, the year of manufacture does not appear to be included on the moulding, as appears on some glassware of GEC lanterns.

The lantern's initial stripping down commenced only days after acquisition; miraculously, every single fixing came undone with ease, and the lantern unscrewed from its bracket without any resistance. The green paint fleck on the canopy hints at an earlier colour scheme for the bracket.

The now-empty inside of the lantern shows that the lampholder bracket fixing holes were set at a 90 degree offset to the refractor spring fixing holes.

The lampholder bracket can be installed any way around (left-to-right, and up-and-down) in the lantern, although the way that it faces depends on the lamp type used. Interestingly, all of the lamp types listed use Philips nomenclature - this side should face downwards when 80 Watt HPL-N (MBF) or 100 / 150 Watt GLS lamps are to be used.

On the inverse, 125 Watt HPL-N, 200 Watt GLS and 160 Watt ML (MBFT) lamps are mentioned.

The two sprung clips that secure the lampholder attach into the canopy with a short threaded section. Notice that the springs are coated in lubricating grease.

Although the lantern has been rewired at some point in the past, using PVC singles cable, the heat generated by the lamp has caused the PVC to discolour and crack in multiple places, exposing the copper conductors within.

Restoration of the lantern commenced in late 2021, with the canopy being sent to R.L. Dumelow & Son, of Burton-upon-Trent for bead blasting and (re)painting. The exterior was painted chrome aluminium...

...while the interior was repainted gloss white. The two bolts visible here are simply sacrificial plugs, to ensure that the threads for the hooks that support the refractor were not clogged with paint.

The refractor was placed in the dishwasher (obviously), in order for it to be cleaned thoroughly.

The reassembled lantern was fitted to a wall bracket on Thursday, 3rd February 2022. A new (old stock) 80 Watt MBF lamp was installed.

The lamp control gear is housed in an enclosure on the other side of the wall. As soon as this was switched on, the lamp emitted the gorgeous mauve glow that is characteristic of mercury vapour lamps that haven't clocked up too many (or any, in this case) hours of operation.

This view demonstrates how the refractor is optimised for the central arc tube, and magnifies / distributes the beam accordingly.

Within a few minutes, the lamp was up to full brightness.

Looking up when standing beneath the lantern demonstrates how the refractor patterns differ at different points, in order that the majority of the beam is spread to the sides, rather than to the front or back.

Lamp warm-up video:

Testing with my energy monitoring device revealed the following results:

Test Voltage (V) Current being drawn at full power (A) Measured wattage (W) Apparent Power (VA) Frequency (Hz) Power Factor True Power (W) Difference to rated wattage Percentage Difference
236.1 0.4 87 94 50 0.93 87.83 7.83 9.79%

Thorn Beta Six / AEI Saxby | AEL Contempo 245




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