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Re: Night Time Pix

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  • Simon Cornwell
    ... The ESLA catalogue featured on my website dates from the late 1930s (the reclassification of the wattages of various discharge lamps by ELMA dates it to
    Message 1 of 19 , Apr 3 10:55 AM
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      --- In StreetlightingUK@yahoogroups.com, SMUK_1994 <smuk_1994@y...>
      wrote:
      > Didn't ESLA's use 80/125w MB/U lamps with
      > Pearl bulbs as they were first introduced in
      > the 1930s in street lighting
      The ESLA catalogue featured on my website dates from the late 1930s
      (the reclassification of the wattages of various discharge lamps by
      ELMA dates it to 1938 at least) but the MB (which was just introduced
      then) is not mentioned. So the ESLA Bi-Multi range, at that point,
      were not designed for the MB.

      MA/V lanterns are shown, but they used vertically stacked directional
      fittings - these are the mercury varients of the ESLA Bi-Multi
      fitting as far as I'm concerned.

      Whilst some versions of the MB do resemble the GLS bulb in outward
      appearence, the GLS has a horizontal wreath filament, whilst the MB
      has a vertical arc tube. (In fact, GLS can be built with either
      wreath or zigzag filaments - both of which have different polar
      curves.)

      In fact, Waldram* ("The Roadmakers Library, Volume 12, p 226") states
      of the MA/V lamp: "For street lighting, the very low downward
      intensity of the lamp is an embarrassment when the lamp is burned
      vertically" i.e. there's hardly any light being distributed below a
      bare bulb. The MB's arc tube is a smaller version of the MA, and
      probably suffers the same problem. The diffusing properties of the
      outer coating probably help, but only in a small way.

      So, to sum up, the polar curves of MB and GLS lamps are fundamentally
      different. ESLA felt (or rather Hyden Harrison felt) that the
      vertically burnt MA should use a different lantern - and I believe he
      would've felt the same way about the MB.

      > I know the MB/U seem to look fifferent
      > lit compared to am modern MBF/U as the
      > Fluorescent coating seems to diffuse the
      > whole bulb where the MB/U looks central
      > where the arc tube is even though the bulb
      > has a Pearl envelope.
      From the exterior, and MB/U and MBF/U look very different. However, I
      would expect their polar curves to be somewhat the same - both are
      being lit by a vertical arc tube. The MBF/U will suffer a little from
      efficiency and will have a wider spread owing to diffusion from the
      fluorescent coating.

      All the best,
      Simon

      *That's J. M. Waldram B.Sc F.Inst.P FIES, Past-President of the IES
      and APLE, and lighting God at the GEC.
    • SMUK_1994
      Ahh I see, Reclassification of Street lighting really didn t take place until after the war as this affected the experiments taking place due to blackout
      Message 2 of 19 , Apr 3 1:32 PM
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        Ahh I see, Reclassification of Street lighting really didn't take place until after the war as this affected the experiments taking place due to blackout requirements, although prewar streetlighting was mainly Filament and Gas there were some installations adotiong SO/H and MA/V lighting in some major towns and cities which was adopted to replace aging Carbon Arc lamps really it was in the 1950/60s when all gas lamps were changed over to Electric lighting is when streetlighting took of using Sodium and Mercury lamps and Fluorescent Tubes, in the mid 1970s when the Iran and Iraq war which resulted in oil crises and energy shortages the lighting authourities changed their street lights to SOX as they were the most economical lamp to run, SON lamps with better light later came into use in city centres and recently is becoming widespread in all aspects of street lighting from side streets to motorway also recently as people want whiter light Metal Halide and Compact Fluorecent lamps have found a suitable use
         
        I think the ESLA looks cool with a Pearl MB/U or Filament lamp rather than the MBF/U and clear GLS althoough I have a Photo on my site showing a 1930s 150w GLS lamp see http://www.freewebs.com/thecolingrimescollection/index.htm
         
        All the Best
         
        Colin

        Simon Cornwell <simon@...> wrote:

        --- In StreetlightingUK@yahoogroups.com, SMUK_1994 <smuk_1994@y...>
        wrote:
        > Didn't ESLA's use 80/125w MB/U lamps with
        > Pearl bulbs as they were first introduced in
        > the 1930s in street lighting
        The ESLA catalogue featured on my website dates from the late 1930s
        (the reclassification of the wattages of various discharge lamps by
        ELMA dates it to 1938 at least) but the MB (which was just introduced
        then) is not mentioned. So the ESLA Bi-Multi range, at that point,
        were not designed for the MB.

        MA/V lanterns are shown, but they used vertically stacked directional
        fittings - these are the mercury varients of the ESLA Bi-Multi
        fitting as far as I'm concerned.

        Whilst some versions of the MB do resemble the GLS bulb in outward
        appearence, the GLS has a horizontal wreath filament, whilst the MB
        has a vertical arc tube. (In fact, GLS can be built with either
        wreath or zigzag filaments - both of which have different polar
        curves.)

        In fact, Waldram* ("The Roadmakers Library, Volume 12, p 226") states
        of the MA/V lamp: "For street lighting, the very low downward
        intensity of the lamp is an embarrassment when the lamp is burned
        vertically" i.e. there's hardly any light being distributed below a
        bare bulb. The MB's arc tube is a smaller version of the MA, and
        probably suffers the same problem. The diffusing properties of the
        outer coating probably help, but only in a small way.

        So, to sum up, the polar curves of MB and GLS lamps are fundamentally
        different. ESLA felt (or rather Hyden Harrison felt) that the
        vertically burnt MA should use a different lantern - and I believe he
        would've felt the same way about the MB.

        > I know the MB/U seem to look fifferent
        > lit compared to am modern MBF/U as the
        > Fluorescent coating seems to diffuse the
        > whole bulb where the MB/U looks central
        > where the arc tube is even though the bulb
        > has a Pearl envelope.
        From the exterior, and MB/U and MBF/U look very different. However, I
        would expect their polar curves to be somewhat the same - both are
        being lit by a vertical arc tube. The MBF/U will suffer a little from
        efficiency and will have a wider spread owing to diffusion from the
        fluorescent coating.

        All the best,
        Simon

        *That's J. M. Waldram B.Sc F.Inst.P FIES, Past-President of the IES
        and APLE, and lighting God at the GEC.



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      • Simon Cornwell
        ... This was the reclassification of the wattages of sodium discharge bulbs (SO) by the ELMA (Electronic Lights Manufactures Association of Great Britain).
        Message 3 of 19 , Apr 4 4:34 AM
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          --- In StreetlightingUK@yahoogroups.com, SMUK_1994 <smuk_1994@y...>
          wrote:
          > Ahh I see, Reclassification of Street
          > lighting really didn't take place until
          > after the war
          This was the reclassification of the wattages of sodium discharge
          bulbs (SO) by the ELMA (Electronic Lights Manufactures' Association
          of Great Britain). This cartel was formed in 1919, formed from
          the 'lamp rings' - groups of manufacturers who fixed wattages, lamp
          life and prices (being basically the GEC, BTH and Siemens).

          After the government stepped in, ELMA eventually became a trade
          union, although today there's still a lot of agreements between the
          lamp manufacturers.

          But I digress. Before 1938, your SO sodium lamps were available as
          50, 70, 100 and 150W. After 1938, ELMA had reclassified them as 45,
          60, 85 and 140W. So, this is a handy guide to dating early SOs and
          lamp and lighting documentation. It wasn't really a street lighting
          reclassification.

          > I think the ESLA looks cool with a Pearl MB/U
          > or Filament lamp rather than the MBF/U and clear
          > GLS
          Fair enough - but I'll be keeping mine as GLS as they were
          originally designed.

          All the best,
          Simon
          www.simoncornwell.com/lighting
        • SMUK_1994
          Hi Simon Cheers for the Clarification/updates All the best Colin ... This was the reclassification of the wattages of sodium discharge bulbs (SO) by the ELMA
          Message 4 of 19 , Apr 4 12:54 PM
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            Hi Simon
             
            Cheers for the Clarification/updates
             
            All the best
             
            Colin

            Simon Cornwell <simon@...> wrote:

            --- In StreetlightingUK@yahoogroups.com, SMUK_1994 <smuk_1994@y...>
            wrote:
            > Ahh I see, Reclassification of Street
            > lighting really didn't take place until
            > after the war
            This was the reclassification of the wattages of sodium discharge
            bulbs (SO) by the ELMA (Electronic Lights Manufactures' Association
            of Great Britain). This cartel was formed in 1919, formed from
            the 'lamp rings' - groups of manufacturers who fixed wattages, lamp
            life and prices (being basically the GEC, BTH and Siemens).

            After the government stepped in, ELMA eventually became a trade
            union, although today there's still a lot of agreements between the
            lamp manufacturers.

            But I digress. Before 1938, your SO sodium lamps were available as
            50, 70, 100 and 150W. After 1938, ELMA had reclassified them as 45,
            60, 85 and 140W. So, this is a handy guide to dating early SOs and
            lamp and lighting documentation. It wasn't really a street lighting
            reclassification.

            > I think the ESLA looks cool with a Pearl MB/U
            > or Filament lamp rather than the MBF/U and clear
            > GLS
            Fair enough - but I'll be keeping mine as GLS as they were
            originally designed.

            All the best,
            Simon
            www.simoncornwell.com/lighting



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          • Mike Barford
            Hi Mike, Thanks for that information - it certainly explains why the time switch suddenly went several hours too fast! Regards, Mike.
            Message 5 of 19 , Apr 5 8:35 AM
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              Hi Mike,
               
              Thanks for that information - it certainly explains why the time switch suddenly went several hours too fast!
               
              Regards,
               
              Mike.
               
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