Old mercury street lamp bulb type

[high_vacuum_house]

Good afternoon,
The last of the old mercury street lamps has recently gone outside where my office is. It is a real shame as they must have been installed in the 50's or 60's and now replaced with a metal pole with an LED head. The nice looking concrete column with its vertical mounted bulb removed. I remember the bluey white glow they gave off as a kid which I much prefer than sodium or other light sources. But nearly all have now gone replaced with LED or sodium. Does anyone know what type of mercury vapour lamp was in these old street lamps.
Many thanks,
Christopher Capener

[Nickthedentist]

This is right up forum member Zelandeth's street (pun unintentional).

[Hunts smoothing bomb]

Hello Christopher,

The lamp would most probably have been an 80w or 125w MBFU which means it is a mercury blended fluorescent. There is a mercury arc tube enclosed in an eliptical bulb which is coated with phosphors on the inside, these phosphors emit light when the UV from the arc tube strikes them, it is known as blended because the phosphors on the inside of eliptical bulb add their own spectrum to the raw light given from the mercury arc which has a very green appearance.

Before these lamps were commonplace street lighting used to employ the "MAV" lamp which was a mercury discharge lamp in a clear envelope so would have been quite poor at colour rendering.

If you are interested in vintage street lighting (like I am) then there are some good sites on the internet.

http://www.streetlightonline.co.uk/

http://www.simoncornwell.com/lighting/


Regards
Lee

[pmmunro]

Christopher,

Why don't you try calling your local council's street lighting office and ask to speak to an engineer?

He/she might be willing to give you a scrap lantern and lamp or at least a lamp and ballast if you explain that you're a responsible person with sufficient technical knowledge to use them safely. Anyone administrative might see the legal dangers too readily but an engineer might be more understanding. You could try the responsible recycling approach, part of which - officially, is to re-use when suitable.

It is however possible that a private contractor looks after the street lighting in your area, in which case you could try contacting them but they might say that there is an agreed procedure for disposal of council property - it's still worth a try.

PMM

PMM

[Tractorfan]

Hi,
I remember seeing these greenish-white lamps, in my youth, along the central reservation on the road that passes through Crownhill, Plymouth and goes towards the Tamar road bridge. I was always curious about them as there weren't any in or around my home town (maybe some in Chester, now I come to think about it).
Cheers, Pete.

[high_vacuum_house]

Many thanks for the links, they are very informative.
I don't think there are any mercury lamps left in Rugby. They are now all a mix of LED, sodium and metal halide. The last time I saw any working was going through a village just west of Peterborough several years ago.
I would like to get my hands on an old street light fitting and get one working even if just as an unusual garden light!! I could call the council about old fittings though I would be surprised if anything comes of it.

Christopher Capener

[Nicklyons2]

Some wer MBTF (mercury ballasted tungsten filament) that's what were used for a while in my area. They take a couple of minutes to get up to full brightness but don't require any ballast - they'll work in an ordinary lampholder. This made it easy when the local authority changed from using 200W GLS lamps in the 'converted' gaslights. Might have a spare nearly new lamp if you're interested. (also a L.P. sodium)

[broadgage]

Yes, probably a mercury fluorescent lamp of 80 or 125 watts, with an E27 screw base. Not much used these days but still available.

Larger wattages exist but were less common.

If anyone is interested in these lamps, I would urge purchasing a few lamps and ballasts as I suspect that production may cease soon. Some countries have prohibited manufacture or import of these lamps.
Whilst I am not aware of any planned restrictions in the UK, it seems doubtful if continued manufacture could be justified by the small and declining UK market.

[Peter.N.]

I also liked the colour of these lights but I think the sodium and certainly the LEDs are more efficient, hence the change.

Peter

[high_vacuum_house]

Originally Posted by Nicklyons2

Some wer MBTF (mercury ballasted tungsten filament) that's what were used for a while in my area. They take a couple of minutes to get up to full brightness but don't require any ballast - they'll work in an ordinary lampholder. This made it easy when the local authority changed from using 200W GLS lamps in the 'converted' gaslights. Might have a spare nearly new lamp if you're interested. (also a L.P. sodium)

Good evening,
Spent all lunchtime going through the 2 websites mentioned above. Very interesting and have bookmarked them for the future.

I would love it if you do find a spare lamp or 2 that would certainly bring back a few childhood memories

Many thanks,
Christopher Capener

[Nicklyons2]

If I've still got it it'll be in the back of my 'airing cupboard' - I'll report back when I've had a look.

[Tractorfan]

Hi,
I used to rig up a couple of 125watt MBTF lamps when painting the ceilings as they made it much easier to see where I'd painted and where I was to do next. The fresh emulsion used to fluoresce ever so slightly.
Cheers, Pete.

[Rhgbristol]

The coding used in Mercury vapour lamp terminology indicates the lamp type and construction.

The typical ones used in street lights from the 1930s onward, used a ballast and power factor capacitor separate from the lamp.

These lamps were termed MBFU in more recent years.The coding M stood for Mercury, B indicated the pressure of the Mercury vapour in the discharge tube, F meant the outer bulb had a fluorescent coating and U signified lamp burning in any position.

Typical ratings were 50w, 80w, 125w, 250 w and 400w. Majority of side road street lighting used the 80 and 125w lamps.
Caps were usually ES or 3 pin bayonet.

The 'blended' Mercury lamp was one that used an internal tungsten filament to act as a ballast, and these lamps had a T in the terminology. Common rating for these was 160w and has usually a standard B22 bayonet.

All are still made but in declining numbers now.

An interesting but little known fact is that when linear fluorescent lighting was introduced in about 1938, the very common 5' 80w tube was so rated so that it could run using the same ballast as that made for the 80w Mercury lamp.

Typical efficacy rating for recent Mercury MBFU lamps was in the order of 70-80 lm/W.

Low pressure sodium (known as sox from the 1960s onwards)
lamps were often used instead of Mercury for street lighting applications, as their efficacy was higher at typically 130 lm/W and their monochromatic yellow colour was very near the human eye's peak sensitivity. Yellow light also good in fog.

Sox fell,out of favour in recent years due to monochromatic lighting being poor or almost non existence for colour rendering and crime prevention.

A red car and blue car both look brown under a sox lamp.

High pressure sodium lamps developed in the 1960s partly addressed this colour rendition issue but at lower efficacy.

Led lighting now beginning to address these issues allowing efficacy and good colour rendition but many led lamps and technology driving them is poorly executed resulting in lamp failure long before quoted typical 80,000 hours.

[cmjones01]

If you're nostalgic for mercury vapour lighting, come to Poland. It's everywhere, usually perched atop charismatic crumbly concrete columns. Lighting on main roads has generally been retro-fitted with pinkish-orange high-pressure sodium bulbs, but in back streets, housing estates and car parks the chilling hue of mercury is very atmospheric.

Chris

[Nicklyons2]

I've found and tried the MBTF lamp 'stashed' in the airing cupboard; yours for the postage if you want it. PM your address if you do,
Nick

[Boater Sam]

They are still on sale on E-bay, new.

[Phil G4SPZ]

I used be responsible for energy management at a County Council where the electricity consumed by street lighting amounted to over one-third of the Council's total. The move to LEDs and other reductions in energy consumption are long overdue.

[G6Tanuki]

Originally Posted by Phil G4SPZ

I used be responsible for energy management at a County Council where the electricity consumed by street lighting amounted to over one-third of the Council's total. The move to LEDs and other reductions in energy consumption are long overdue.

Here in Wiltshire there's any street lighting it's still a mix of MBFU and Sodium, though with LED coming in rapidly where any repairs/replacements are undertaken. In quite a number of areas they're turning the street-lights off after midnight to save energy.

Personally, I like the colour-rendition of the LEDs compared to sodium; it's much easier on the eye. So far I've not noticed any significant change in the RFI level from the LED installations; a few years back though there was one low-pressure-sodium I drove past regularly that put out enough 'hash' on 144MHz to block reception of the local repeater over about 1/4 mile. It took several complaints to the highways-people to fix it.

[Zelandeth]

Interesting...Can't think for the life of me why a low pressure sodium lamp would be throwing out RFI like that...the ballasts are generally just an autoleak transformer. The high pressure sodium lamps with superimposed ignitors can throw some real garbage out, but only for a few seconds when the lamp starts generally. You can get some interesting RF effects from the lamps if you get uneven wear on the electrodes, quite often at surprisingly high frequencies at harmonics of the main frequency, but I wouldn't have expected anything like that sort of range...I'm curious now and kind of wish I could have examined the unit in question...

As others have already said, the lamps mentioned in the original post were most likely 80W or 125W MBF lamps, which are still relatively easy to come by. However as of a year or two ago (can't remember the precise date off the top of my head), production and import of mercury vapour lamps into the EU has been banned, so most places are just going to be using up old stock, and the days for a lot of these old installations really are numbered. As it is, they are still readily available it seems from the likes of eBay or older wholesalers who will probably still have old stock on the shelves. Still envious of a couple of mates who managed to find a couple of old Atlas made 80W Delux Natural colour bayonet capped fluorescent tubes in one such old shop.

Blended mercury (MBT or MBTF) lamps weren't as far as I'm aware massively widely used for streetlighting (they offer relatively little in the way of energy savings over incandescent lamps) at around 15-20Lm/W, but were quite commonly used for industrial lighting where slightly better colour rendering was needed than mercury alone could offer. They did become a popular incandescent retrofit in industry as well because of the vastly longer lamp lives.

Blended lamps do get a mention as well as being the only light source which involves a warmup time that actually gets *dimmer* as the lamp warms up...

My opinion is that the mass switch to LED streetlighting is slightly premature. High pressure sodium and metal halide technology (from reputable sources!) compete well for efficacy and give much more consistently long lives, fluorescent technology is also a good contender for the lower output shorter columns in residential areas. The big issue with LEDs at the moment still seems to be that the lifetime of the drivers is hugely variable.

In the town I used to stay in quite a few areas had been changed to LED from SON, and about a year later were changed again, this time to fluorescent because they had suffered so many premature failures (this was done at the supplier's cost I might add!).

We've recently seen quite a mass change to LEDs down here in Milton Keynes, and I commend the LED lanterns they've used for their output, especially the larger ones on the main grid roads which really are impressive. One running theme I'm seeing though six months or so on is that I'm seeing a LOT of these new lanterns out...so long term reliability looks like it might not be the best...

They are also horrifically expensive compared to the traditional discharge options when it comes to initial purchase. Water gets into a SON lantern, you replace the ballast which costs a few quid. Water gets into an LED lantern and it's a several hundred quid write off.

I'm not bashing LED tech, and I do honestly believe that it is the future. I just think that if I was running a streetlighting department (which I don't, but I did until a year or so back have daily contact with them as I looked after other street furniture which usually had power feeds from lighting columns), I'd probably be waiting another three to five years before I would consider wholesale switchover.

For me at the moment I'd be sticking with fluorescent for residential and SON for highways, simply because they are decently efficient and reliable.

SOX (low pressure sodium) kicks the lot of them in efficacy terms, but the monochromatic amber colour puts a lot of people off, and while the gear is nigh on indestructible, the quality of the lamps has fallen off a cliff in the last five years or so and given that only Philips are still making them in one factory the prices have shot up into the stratosphere. For those reasons I feel that low pressure sodium is basically dead barring some unexpected miracle.

Nothing can beat old MBF lamps and gear for longevity though...Which is one of the reasons they were so popular in addition to being cheap. Generally they just lost output and turned more green as they aged until they would usually be replaced due to loss of output rather than being outright dead. My experience with mercury gear is that unless it gets drowned that it basically never* fails.

*Okay, there will always be occasional failures, but these things were very, very reliable.

That's turned into enough of a ramble from me (hey...me talking about lighting that's turned into a novel? Surely not...) so I'll wrap up here before people start hurling things at the stage again...

[happytiger]

I have several MBFT lamps 250 W GES base, I use one in the dining room, an excellent efficient light.
The GES base was common use for street lighting. and industrial use.