As the title suggests, when were the Lifeguard electrodes removed from Philips lamps?

I would say sometime between 1994 and 1998.

I have a Philips bulb from 1992 with large electrodes and one from 1995 with small electrodes.

I am pretty sure it is 1995 then, because I have a Philips 175W MV bulb on my eBay watch list from 1994 with modern Philips packaging and design, yet it still has the huge Lifeguard electrodes.

The “Lifeguard” electrodes were in fact never stopped - only the brand name was phased out.   Lifeguard refers to the type of emitter coating on the electrodes.  That was first introduced from Europe to America by GE in 1958 with its Bonus Line brand, followed by Sylvania’s Banner brand in 1960 and finally Westinghouse’s Lifeguard brand in 1961.

This style of emitter coating was maintained almost without change right up to the present day.  It became so ubiquitous that once all manufacturers had it there was no need for a separate brand name to indicate its presence.  As far as I know, Westinghouse dropped the name in 1989.

In the years following the takeover by Philips, several improvements were made to the dimensions of the Westinghouse electrode coils designs but always maintaining the same basic “Lifeguard” design.  One problem with some of Westinghouse’s electrodes was that they were simply too big.  Aside from wasting costs, they conducted too much heat away and notably lowered lamp efficacy and lumens.  Some also took too long to transfer from the initial glow discharge to the arc, after switching on.  That caused accelerated degradation and lumen depreciation during life.  A long overdue improvement was triggered by the lumen and life race of the 1990s, when all manufacturers became much more competitive and could no longer afford to keep outdated inefficient designs in production.  Customers were beginning to realise that Westinghouse’s mercury lamps were actually pretty poor by comparison to foreign competition and even other USA manufacturers. Their lumen output was worse and they blackened faster.  The electrode improvements introduced by Philips helped raise both the initial as well as through-life performance to much more competitive levels.

This emitter turns the arctube white, so why the arctube turns black then?

@James Ah, I see. But I thought that the bigger electrodes made the bulbs last longer? Isn't that right?

Lasts longer at the expense of lumen efficacy I think.

@dor123 - I think you are right. That's why they are the everlasting bulb, but not necessarily the brightest throughout life...

There is an optimum electrode dimension and geometry for each lamp wattage / current rating.  If the electrode is too small its life will be reduced due to higher temperature operation - but also if it is too big, life will be reduced due to delayed GTA (glow-to-arc) transition time and increased sputtering damage.  Westinghouse's old designs were apparently quite severely oversized and date back to a time when these finer details were not known.  Other manufacturers upgraded their electrodes quite early, but Westinghouse was kind of left behind from about the 1970s onwards.  Some of its lamps may indeed have lasted quite long, but since a lamp typically consumes about a hundred times more cost of electricity than its own initial purchase price, consumers quickly began to realise that it was costing them a lot to buy those inferior old lamps that consumed a lot of power for a rather low light output.

@dor123 the emitter coating indeed has a whitish colour, but tungsten is also lost from the electrodes and that is black.  The net result is that the arc tube appears to become black as it ages.

Would that mean that the big electrodes would only increase life when the bulb is run continuously with zero shutoff? But when run D2D, it would result in lower life, yes?

That’s a good point!  I don’t know for sure, but I suspect your theory is probably correct.

Just two questions, James. I've always noticed how small the auxiliary electrode is in mercury vapor lamps. Would making it bigger, meaning thicker, increase the number of times you could start the lamp, or would it just sputter away and decrease the number of starts you could do? Second, why is the section on electrodes for MV lamps crossed out on your website and not found on the server?

The “Lifeguard” electrodes were in fact never stopped - only the brand name was phased out.   Lifeguard refers to the type of emitter coating on the electrodes.  That was first introduced from Europe to America by GE in 1958 with its Bonus Line brand, followed by Sylvania’s Banner brand in 1960 and finally Westinghouse’s Lifeguard brand in 1961.

This style of emitter coating was maintained almost without change right up to the present day.  It became so ubiquitous that once all manufacturers had it there was no need for a separate brand name to indicate its presence.  As far as I know, Westinghouse dropped the name in 1989.

In the years following the takeover by Philips, several improvements were made to the dimensions of the Westinghouse electrode coils designs but always maintaining the same basic “Lifeguard” design.  One problem with some of Westinghouse’s electrodes was that they were simply too big.  Aside from wasting costs, they conducted too much heat away and notably lowered lamp efficacy and lumens.  Some also took too long to transfer from the initial glow discharge to the arc, after switching on.  That caused accelerated degradation and lumen depreciation during life.  A long overdue improvement was triggered by the lumen and life race of the 1990s, when all manufacturers became much more competitive and could no longer afford to keep outdated inefficient designs in production.  Customers were beginning to realise that Westinghouse’s mercury lamps were actually pretty poor by comparison to foreign competition and even other USA manufacturers. Their lumen output was worse and they blackened faster.  The electrode improvements introduced by Philips helped raise both the initial as well as through-life performance to much more competitive levels.

I am not so sure that Philips Did make improvements, if you have a search around on LG, its pretty well documented that, US Philips Mercury lamps from after they abandoned Westinghouse designs, where known for going quite dim quite quickly, to the point people found that later Chinese examples lasted better

for example see the comments in this upload

https://www.lighting-gallery.net/gallery/displayimage.php?pos=-87279

and then an actual picture comparison of the dim lamp!

https://www.lighting-gallery.net/gallery/displayimage.php?pos=-11380

and I remember other such reports on LG back in the day


also with regards to electrode-size, many US ballasts setups are of the CWA type with a higher current crest factor than that of a European choke ballast, thus correct me if I am wrong, but as I understand it you need larger electrodes to compensate for that higher crest factor

(as I write this, I do almost wonder if Philips forgot about this fact themselves when they released their own design of mercury lamp after the Westinghouse take over, hence the resulting poor lumen maintenance thats so widely reported for those Philips lamps?)


to that end, I cant say I have heard of poor performance from Westinghouse lamps being reported, sure there might be some survivorship bias in play, but I think there is good reason that the Westinghouse Mercury lamp is quite legendary on LG, I think of all the "still reasonably bright, and having done many many hours" used mercury lamps spotted in the wild or pulled from service, by members here on LG the majority of them have been Westinghouse life-guards

of course I cant talk about raw lumen figures, I have never stuck a Clear Westinghouse 175W lamp into an integrating sphere and compared it with its period competitors (I figured thats something you would of done ) so it could well be, that Westies where slightly dimmer/less efficient,

but I certainly do not think they where poor performers otherwise, and I do really have to question if Philips actually made improvements given the awful performance reported by people on LG of those lamps?

I would very much welcome your thoughts on this!

My views are based on comments from ex-Westinghouse staff, who never seemed to refrain from cursing their former employer in terms of the huge cutbacks it made on the lamp division’s investments since the 1970s.  This was a source of great frustration as they saw their designs becoming progressively backward while other competitors achieved continual performance improvements.  Similarly, there is a plentiful source of comments from the competition about how much easier their lives became when one of their former major competitors basically decided to stop innovating in all but a few areas it could afford.

Indeed there are a lot of collectors who claim that at least some Westinghouse mercury lamps had very impressive lives.  There can be no doubt that this is not true, but such comments have to be put into perspective vs the possibly long-forgotten complaints of premature failures and poor performance that was often reported decades ago - one of the reasons for the company’s declining market share and financial fortunes.

The objective of any manufacturer should be to make all of its production as consistently good as possible, and in line with customer expectations.  But when it begins to fall behind and under-invest, with slack process controls, variations are inevitable.  Some lamps will perform better than others in terms of initial output, but due to their higher loading the life will be reduced.  Similarly, some will start out under-performing and live much longer.  Precisely the same was true with incandescent lamps, where a similar situation exists when we consider examples like the century-old Shelby lamp still burning at Livermore.  The average person looks to that as some remarkable example of how much better the old bulbs must surely have been.  But every lamp engineer looks on it with disgust, to see how appallingly poor their quality control must have been to produce some lamps with such terribly low efficacy that they still work a century later - having cost the owners a massive fortune in wasting so much electricity to produce so little light.

I am afraid the same may apply to Westinghouse mercury lamps.  People naturally look on the tiny numbers of surviving examples in awe for having worked so long.  But are not aware of the dissatisfaction of the original owners for all the rest that failed so prematurely that the company began to get a bit of a bad reputation, became unprofitable, lost market share, and then fell behind vs its competitors superior designs.

I am quite certain that Philips will not have overlooked anything when updating the design of Westinghouse’s antiquated mercury lamps.  That company was almost pathological in its search for excellence - so much so that it perhaps went too far in the opposite extreme vs Westinghouse.  It invested its own fortunes in employing legions of lamp engineers to squeeze out every tiny performance advantage from its designs - in such minute detail that perhaps 99% of its customers would never even become aware of that superiority, or reward the company by paying any more for its products.  As such it encountered its own severe profitability challenges during the late 1990s and early 2000s when the new industry of global sourcing began.  During the extremely painful era of the Philips Operation Centurion, it was forced to lay off vast numbers of its lamp research and engineering staff, and shut down scores of its state-of-the-art factories in search of lower cost suppliers.  Otherwise the company would surely have gone bankrupt, and disappeared two decades earlier than it ultimately managed to survive.  As is so often the case, the companies that survive on the longer term are not necessarily the best, the richest, the strongest or the biggest.  And those that are eliminated are typically also not the weakest or worst.  As the best friend of my great great grandfather, Charles Darwin would say, the ones that survive are those which are most adaptable to a change in their environment.  The laws of evolution, it would seem, apply equally well to corporate longevity as to biological life!  In conclusion we cannot really say that Westinghouse lamps were necessarily good or bad - only that they failed to keep up with evolving market demands.  As a result the company as well as its outdated lamp designs were eventually superseded by something that proved to be considerably more commercially viable, thanks to the investments of a new owner which at the time benefitted from the necessary market insights as well as financial fortunes.