WRTL 'Arc 90' 2695

Lantern acquired in February 2019.

This 250 Watt version of the popular WRTL (Industria / Indal / Philips) Arc lantern is believed to have been removed from column 48741 on the short dual carriageway section between the M1 motorway at Junction 29 (Chesterfield) and the small village of Doe Lea, just off the A617 at Glapwell, on approximately Monday, 25th February 2019, following the decommissioning of its twin-arm 12 m lighting column in preparation for the installation of a replacement column supporting two CU Phosco P862 90 Watt LED lanterns shortly afterwards. Owing to the increased power consumption, the 250 Watt SON Arc was used sparingly in Derbyshire, with the 150 Watt version being far more common on major roads throughout the County.

This image, taken from Google Street View, shows the double-arm column that, I believe, supported this lantern. The second lantern was rescued too, and has been passed on to another collector. The lanterns fitted before the Arcs were installed are unknown, but may have been 180 Watt SOX equivalents.


Unlike my 150 Watt Arc 90, which had suffered cosmetic damage to its canopy during removal, this lantern's canopy is undamaged - the grass verge may have softened the blow when the column was brought to the ground.

Owing to this lantern being of about the same age as the 150 Watt version is, the original, slightly glittery, finish applied to the canopy has faded in strong sunlight over the years.

A Royce Thompson Oasis 2000 photocell, rated at 55 Lux, is fitted. This is likely to be the lantern's original photocell.

A reducer cylinder fits into the bracket entry, allowing UK-style 42 mm brackets to be accommodated into the wider European 60 mm entry.

The Arc 90 was produced with a choice of curved or flat glass optics; this example is of the former type. As acquired, a short length of the bracket remained fitted in the lantern, but this was removed. The innermost grub screw employed to secure the lantern to the bracket was jammed and had to be coaxed free using a ratchet driver and a liberal spraying of WD40.

The lantern interior is sealed to a rating of IP66, as is the lamp optic.

The canopy hinges open, and remains fixed in this position until this locking mechanism is released manually.

The gear comprises a ballast and ignitor made by Venture Lighting, and an Italfarad capacitor, rated at 30 F. A date stamp on the other side of the ballast indicates that it was made on the 30th April 2003, with the capacitor dating from May of the same year.

The components are all installed on a removable plastic tray; here is how the lantern appears without the gear connected...the overall weight is reduced significantly!

The lampholder is attached to a plug that seals the optic when inserted. For ease when replacing the lamp, the cable feeding it can be unplugged.

The lantern was fitted to a wall bracket on Thursday, 31st December 2020.

The new 250 Watt lamp warmed up rapidly, producing a blindingly bright beam within only a few minutes.

Pointing the camera directly at the lamp under-exposed the image, allowing the glowing arc tube to be seen.

Lamp warm-up video:

Testing with my energy monitoring device revealed the following results; these proved that the seventeen-year-old capacitor had failed:

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
240.9 2.47 289 595 49.9 0.47 279.66 29.66 11.86%
CU Phosco P852 | CU Phosco P567A

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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