Philips MA 50

Lantern acquired in May 2011.

This lantern came from column 36396 on Uttoxeter Road, Mickleover; its removal brought about by a relighting scheme as part of Derby's Street Lighting PFI in April/May 2011. The column was a sleeved Stanton concrete, and would have originally been 8 m in height, with a 90 Watt SOX lantern fitted. I had previously thought that the columns were sleeved (and their heights increased to 10 m) in the early 1990s; however, the acquisition of this lantern suggests a slightly earlier date. As there was no adjacent replacement column for this installation (due to the new column being installed on the other side of the road), there was no need to wait for the service to be disconnected - the replacement column was already in use, and the lantern could be removed from service without creating a dark spot on the road. The lantern and gear were therefore removed on Tuesday, 3rd May 2011; being picked up on Monday, 16th May. Column 36396 was finally removed on Saturday, 14th May.

The inventory record for the column (as it appeared in 1997) is displayed below:

Unique Number: 36396 Location: O/S ROWDITCH FURNIS
Postcode: DE3 5DA Road: UTTOXETER RD
Road Number: B5020 Parish: MICKLEOVER
Sequence Number: 13 Patrol: Y06
Lamp Type: SXP3 Wattage: 135 Watt Control Type: PE2E
Lamps/Lantern: 1 Lanterns/Unit: 1 Control Setting: 4
Lantern Type: SE Lantern Manuf:   Control Gear:  
Height: 10  m Support Type: CM CONC COL/METAL SLEEVE
Bracket Proj'n.:    m Support Finish: U UNPAINTED SUPPORT
Bracket Type:   U/G or O/H: U UNDERGROUND
Board Code: E76 Status Code: 0 USUAL / NORMAL
Service Owner: A Is this lamp/sign an Isolation Point ?: N
EB Order number:      
No-supply sheet: 0 Isol Pt :   / Circuit:   / Seq:  
    Location :          
    Road :          
    Parish :          


LAMP FITTED 07 05 1996

The first few photographs show the lantern whilst still installed.


These first couple of photographs were taken on Saturday, 2nd April 2011, just after the new columns had been installed. The lantern's canopy was in a rather grubby condition, and dirt had accumulated in the lower portion of the bowl.


The lantern was still surviving and in use on Sunday, 17th April.


As this lantern is remotely-geared, the lamp extends to the full length of the lantern. The same lantern body is used for the integrally-geared, gear-within-lantern version of the MA 90, and the integrally-geared, gear-within-shoe version of the MA 50.


Notice that the canopy appears significantly cleaner in this photograph than it appears to have been whilst still installed. This is because the lantern was given a high dose of "pressure washer" treatment before these pictures were taken, in order to remove the worst of the moss and lichen that had accumulated on the canopy over the years. The canopy fibres are shedding quite badly, and further restoration will be required in order to prevent this from worsening. The two 'fins' in the rear aluminium casting are provided in order to assist with ensuring correct alignment of the lantern during installation.


The pool of dirt at the lowest portion of the bowl had also been removed. This must have proved a common fault with these lanterns, as later bowls feature a small plug in this section, which helps to alleviate the build-up of debris. Additionally, later lanterns incorporate another clip at the front of the bowl, to improve the IP rating of these lanterns.


The inside of the lantern couldn't be more different - it is still in (virtually) new condition. The lamp support in this lantern consists of an appropriately-shaped metal rod, which simply clips into the desired lamp setting position. Later versions incorporated a more elaborate (but better fitting) sprung lamp support. The lampholder positions can also be adjusted by a small amount. Position 3 is the 'standard' semi-cutoff distribution setting, and Position 1 is for a cutoff distribution. Position 2 is also for semi-cutoff distribution; however, this setting is only intended for use in Europe.


The identity label contains various codes and numbers, but I believe that the 'LHB915' in the top-right corner is the date code; specifically "B9", as my MA 60 carries "5H" in its code, which would signify August 1995, and would be accurate. Therefore, I believe that this lantern was made in February 1989. This theory is backed up by the age of the gear components...


The ballast carries a similar code; its being "LHD9" (April 1989). The Fisher Karpark SS55 photocell controller is dated to May 1989 (two dots are stamped into the plastic alongside '1987' (the highest year etched on the case)). The ESTA capacitor is dated to April 1988, and carries the historically (and politically) interesting statement that it was made in West Germany. The ignitor is the only 'new' component; it being a replacement fitted in either February or July 1998.


Restoration of the lantern commenced in earnest on Friday, 27th October 2017 - such was the lantern's excellent condition upon being removed from service that the only work required was to paint the canopy exterior, in order to prevent the fibres from shedding, as mentioned earlier. The rear shoe was removed during this work.


The canopy looked (almost) as good as it did when being assembled into a working lantern some 28 years earlier.


Reassembly followed; thanks to the nature of the lantern, this process was very quick, and in no time at all, the lantern was complete again.


The photocell detector was re-fitted, even though the lantern will not run in this way in preservation. The yellowed plastic of the detector provided a sharp contrast with the surrounding freshly-painted cream canopy!


The patented "dunk the bowl in the bath" method was employed here, and did rather a good job of removing the surface dust that had gathered on the lantern since its original basic cleaning.


The inside of the lantern was wiped thoroughly, in order to remove any remaining signs of dirt.


The lantern was attached to a wall bracket on Friday, 1st December 2017.


Once power was applied, the faithful Philips-made OSRAM lamp struck up without issue. Owing to the six-and-a-half years that had passed since the lamp was last lit, warm-up was noticeably slower than it is on lamps that have seen more regular operation.


Eventually, the room was illuminated in the unique glow that only a low pressure sodium lamp can produce.


Lantern operation video:

Testing the lantern with my energy monitoring device revealed the following results; amazingly, the total power consumption was somewhat lower than the stated wattage of the lamp was, and the Power Factor was one of the best I have ever seen on a SOX lantern:

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
241.9 0.51 119 123 49.9 0.97 119.67 -15.33 -11.36%

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