WRTL 'Arc 80' 2687

Lantern acquired in March 2017.

This lantern was removed from column 8216 on the A516 dual carriageway in Mickleover; the double-arm column being removed from service on Friday, 17th March 2017 as part of road realignments that would see the construction of a new roundabout providing access to a new housing development on the opposite side of the A516; the same scheme that saw the acquisition of five other lanterns for the Collection. This lantern was, presumably, a replacement for a defective Thorn Pilote T2 lantern of equivalent wattage; the other lantern on the double arm being such a product. Along with the larger Arc 90 lantern, the Industria / WRTL / Indal / Philips Arc lantern is a common sight in Derbyshire; its popularity being attributable to the variety of lamps and mounting heights that it could accommodate. This smaller version of the Arc was intended for side road use, although the 150 Watt variant, of which this is, acted as the 'transition' between the two types; it being an option with both sizes, and so, saw main road use as well.

The double-arm column that supported this lantern (foreground), on the 20th January 2017 - a few days after the westbound carriageway was closed to non-construction traffic, the road surface had been dug up and a contra-flow was in place on the eastbound carriageway.


By the 6th March, the roundabout construction was progressing steadily, although the westbound carriageway remained closed at the time.


The lantern on a rainy 18th March; a day after its column had been brought down. Notice the discarded Pilote bowl alongside.


Oddly, the double-arm bracket had been cut, leaving a short section of bracket connected to the lantern.


The lantern carried a 'battle scar' from where it had been scraped along the carriageway after its column was cut down. Although the lantern was fitted with a photocell when in use (not that this was required; the lighting along the bypass being group-controlled), the photocell was missing upon the lantern's acquisition. The white object propped behind the NEMA socket is still a switch, however - a convenient three-gang plate switch used as a way of preventing the lantern from rolling over while its side-on picture was being taken!


As with the larger 'Arc 90' that was also acquired from the bypass, the paint finish applied to this lantern's canopy has dulled over the years, although this lantern is slightly newer.


The Zodion-made NEMA socket is dated to July 2005.


The polycarbonate lantern bowl has yellowed slightly during the fitting's time on the road.


Opening the lantern reveals its internal construction, along with the wiring and lamp control gear.


The hinged canopy locks into its 'open' position by means of a sprung metal strip. This must be released manually in order to close the canopy. Also visible on the inside of the canopy is the fixing hole and support fins for the reflector on versions of the lantern where it lifts away from the bowl and lamp during maintenance visits.


The ballast and ignitor are made by Tridonic, whilst the capacitor is made by Italfarad. All components were made between July and September 2005, and the gear tray itself carries '0549'; suggesting that the components were fitted and wired on week 49 of the year (between the 5th - 11th December). The lantern part code on the label ('ASR150BN') can be interpreted as follows:

A = Arc Lantern

SR = Side Road version

150 = Wattage

B = Polycarbonate bowl

N = NEMA Socket


Access to the sealed optic area is gained by rotating the black plastic end piece at the front of the reflector anti-clockwise until the indicator arrow is adjacent the 'O' (Open) marker. The cable supplying the lampholder can be disconnected from this section, in order to allow the lampholder to be removed more easily.


Although the end piece is a common size on both this size of the Arc, and the larger version, the lampholder is positioned differently on both, owing to the optics on both lanterns being of proportions. Although the smaller Arc will run 150 Watt lamps without a problem (just as well; given that this lantern is so equipped!), the larger lantern offers a marginally improved spread of light with this wattage. The Philips-made SON lamp carries the date code of '0L', which represents November 2010. A hand-written date on the lamp cap suggests that the lamp was fitted in April 2011; probably as part of a bulk lamp changing session; given the expense involved in repairing street lighting that is located within the central reservation of a multi-lane carriageway.


The factory-set lateral focus position is 'C'; the central position. The equivalent vertical focus position is '1'.


The following photographs demonstrate the size difference between the small and large Arc lanterns - the small lantern measures (L) 670 mm [2 ft 2.4 in] (W) 325 mm [1 ft 0.8 in] (D) 275 mm [10.8 in], including the bowl. The large lantern measures 775 mm [2 ft 6.5 in] 380 mm [1 ft 3 in] 250 mm [9.8 in], including the curved glass, but excluding the photocell.


The smaller optic necessitates the need for the lampholder to be more recessed into the end section, though both lanterns are set to the same focal position - 1C.


The lantern was stripped of its gear and optic (in preparation for a surface clean of the metalwork) on Friday, 4th May 2018.


The reflector and bowl are bonded together (ensuring a high IP rating), but this is not quite so helpful when the optic needs to be cleaned internally! In the end, I poured soapy water in through the lamp entry point, and then wiped the interior with a cloth. This didn't remove the yellowing to the bowl, but still helped to clean it somewhat.


Attachment to a wall bracket followed.


In my haste to reassemble the lantern, I hadn't given its interior sufficient time to dry out following the wash. This resulted in poor insulation resistance between earth and both live and neutral when the lantern was tested prior to being powered up. Therefore, I had to wait about a week for the lantern to dry out before I was able to run it - had I attempted to do this sooner, in all likelihood, the RCD protecting the house's sockets would have tripped. Following a re-test, the insulation resistance readings were now clear, and so the lantern was plugged in and switched on. The smaller optic made for a slightly more glary overall appearance, I found.


Lamp warm-up video:

Testing the lantern 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 (W) Percentage Difference
241.9 1.04 183 252 49.9 0.74 186.17 36.17 24.11%

WRTL 'Arc 90' 2695 | Philips SGS 203

WRTL Arc Lanterns in the Collection

Arc 80 (70 Watt) Arc 80 (150 Watt) Arc 90 (150 Watt) Arc 90 (250 Watt)




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