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Insulators in Overhead Contact Wire -- Model Trolleycars

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  • Jim Holland
    Greetings! ... As a rule, the hanger was an insulator and the span was not energized at all. If the hanger was not self insulating, then insulators were used
    Message 1 of 3 , Nov 10, 2000
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      Greetings!

      John Bishop wrote:

      > Thanks for your kind words. Actually the picture was taken by my son, Joe
      > Bishop, who set up and maintains the web site.

      > . . . which is why I have insulators between the contact wires, which I
      > don't think was usual for the prototype.

      As a rule, the hanger was an insulator and the span was not energized
      at all. If the hanger was not self insulating, then insulators were
      used immediately on either side of the hanger. Rarely was the span
      energized.
      Even with self insulating hangers, it was not uncommon to see an
      insulator attached to the hanger - esp. on the side leading to the line
      side pole. And quite often another insulator was in the span at the
      line side pole itself. Safety with 600-volts!!

      > Any ideas as to the best way to make block insulators in the contact wire,
      > especially when a large number are needed?

      Something that I have often thought about. Here is an idea to try.

      Choose your materials - wood, styrene, etc. The thickness of the piece
      to make the gap in the wires needs to be the same size as the diameter
      of the overhead. Cut this piece to the desired length for the gap -
      just enough so the largest shoe or pan can not bridge the gap to help
      prevent a car from getting stuck on it (the prototype did get stuck on
      these!) Then sandwich this between two pieces of material that extend
      about 1/4" on either side of the gap. Make sure that the gap protrudes
      below these side pieces so that the shoe will not make contact with
      them. These should be glued together.
      Then use some brass (if at all possible rather than wood//styrene
      although wood could be used) whose thickness is the same diameter as the
      trolley wire. These are the end pieces on either side of the gap and
      can be glued in place to allow the contact wire to pass between the gap
      and the brass so leave enough spacing between the two for the wire.
      ALSO, glue it in place so it sits higher in the insulator by the
      thickness of the wire.
      The contact wire will come in under the brass, be bent to pass up
      between the brass and the gap, and bent back on top to stay in place.
      If at all possible, tack solder the wire to the outer end of the brass
      on either side of the insulator.
      This should keep the contact wire flush with the gap for smooth
      passage. Tack soldering to the brass prevents the wire from sitting
      beside the brass and causing a snag with a pan or dewirement with a
      pole.
      Cut off any excess and shape the top to make it look acceptable.

      James B. Holland

      Pittsburgh Railways Company (PRCo), 1930 -- 1950
      To e-mail privately, please click here: mailto:pghpcc@...
      N.M.R.A. Life member #2190; http://www.mcs.net:80/~weyand/nmra/
    • Jim Holland
      Greetings! Revision of my original post is included below. Photos can not be included on this list; they were sent to interurbans@egroups and can probably be
      Message 2 of 3 , Nov 10, 2000
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        Greetings!

        Revision of my original post is included below. Photos can not be
        included on this list; they were sent to interurbans@egroups and can
        probably be viewed there in the archives.

        ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

        Enclosed are 2-photos from the Ohio Brass (OB) Catalog #25 showing
        2-distinctly different overhead insulators used in trolleycar contact
        wire.
        The first one (inslprco.jpg) was quite common in Pittsburgh and was
        made for wheels. OB makes (made) the same insulator for shoe and the
        insulating runner is l-o-n-g-e-r!!::->) This is the one I described
        below and would probably be easiest to assemble for models.
        The second one (insl-2.jpg) is far more common and is even used in
        trolley-coach overhead. There are 2-other types of overhead insulators
        that look like variations of this particular one.

        Please note that I am making a clarification to my post below:::::::

        Jim Holland wrote:

        > > Any ideas as to the best way to make block insulators in the contact wire,
        > > especially when a large number are needed?

        > Something that I have often thought about. Here is an idea to try.

        > Choose your materials - wood, styrene, etc. The thickness of the piece
        > to make the gap in the wires needs to be the same size as the diameter
        > of the overhead. Cut this piece to the desired length for the gap -
        > just enough so the largest shoe or pan can not bridge the gap to help
        > prevent a car from getting stuck on it (the prototype did get stuck on
        > these!) Then sandwich this between two pieces of material that extend
        > about 1/4" on either side of the gap. Make sure that the gap protrudes
        > below these side pieces so that the shoe will not make contact with
        > them. These should be glued together.
        > Then use some brass (if at all possible rather than wood//styrene
        > although wood could be used) whose thickness is the same diameter as the
        > trolley wire. These are the end pieces on either side of the gap and
        > can be glued in place to allow the contact wire to pass between the gap
        > and the brass so leave enough spacing between the two for the wire.
        > ALSO, glue it in place so it sits higher in the insulator by the
        > thickness of the wire.

        REVISING the last sentence:: ALSO, glue the brass in place so it sits
        higher than the runner gap by the diameter of the trolley wire.

        > The contact wire will come in under the brass, be bent to pass up
        > between the brass and the gap, and bent back on top to stay in place.
        > If at all possible, tack solder the wire to the outer end of the brass
        > on either side of the insulator.

        When the trolleywire comes in under the brass, it will be perfectly
        flush with the runner-gap for smooth passage of the shoe.

        > This should keep the contact wire flush with the gap for smooth
        > passage. Tack soldering to the brass prevents the wire from sitting
        > beside the brass and causing a snag with a pan or dewirement with a
        > pole.

        This is also why it is better to use brass than wood so it is possible
        to tack solder. I know - this will be difficult!!

        An alternative is to glue a piece of contact wire between the side
        sills near the runner-gap for passage of the contact wire between the
        runner and this wire. Glue it in so that it forces the incoming contact
        wire to be flush with the gap. Also make sure that the contact wire
        stays clear of any insulator overhang to prevent dewirement.

        > Cut off any excess and shape the top to make it look acceptable.

        James B. Holland

        Pittsburgh Railways Company (PRCo), 1930 -- 1950
        To e-mail privately, please click here: mailto:pghpcc@...
        N.M.R.A. Life member #2190; http://www.mcs.net:80/~weyand/nmra/
      • Jim Holland
        Greetings! Forgot to mention measurements:: for inslprco.jpg, the total under run is 30.5-inches but this does NOT include the tips that are used to make
        Message 3 of 3 , Nov 10, 2000
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          Greetings!

          Forgot to mention measurements:: for inslprco.jpg, the total under run
          is 30.5-inches but this does NOT include the tips that are used to make
          smooth passage of the wire to the insulator.
          For the second one, the length varies from about 16-26-inches, again
          exclusive of tips.

          Jim Holland wrote:

          > Greetings!

          > Revision of my original post is included below. Photos can not be
          > included on this list; they were sent to interurbans@egroups and can
          > probably be viewed there in the archives.

          ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

          > Enclosed are 2-photos from the Ohio Brass (OB) Catalog #25 showing
          > 2-distinctly different overhead insulators used in trolleycar contact
          > wire.
          > The first one (inslprco.jpg) was quite common in Pittsburgh and was
          > made for wheels. OB makes (made) the same insulator for shoe and the
          > insulating runner is l-o-n-g-e-r!!::->) This is the one I described
          > below and would probably be easiest to assemble for models.
          > The second one (insl-2.jpg) is far more common and is even used in
          > trolley-coach overhead. There are 2-other types of overhead insulators
          > that look like variations of this particular one.

          > Please note that I am making a clarification to my post below:::::::

          > Jim Holland wrote:

          > > > Any ideas as to the best way to make block insulators in the contact wire,
          > > > especially when a large number are needed?

          > > Something that I have often thought about. Here is an idea to try.

          > > Choose your materials - wood, styrene, etc. The thickness of the piece
          > > to make the gap in the wires needs to be the same size as the diameter
          > > of the overhead. Cut this piece to the desired length for the gap -
          > > just enough so the largest shoe or pan can not bridge the gap to help
          > > prevent a car from getting stuck on it (the prototype did get stuck on
          > > these!) Then sandwich this between two pieces of material that extend
          > > about 1/4" on either side of the gap. Make sure that the gap protrudes
          > > below these side pieces so that the shoe will not make contact with
          > > them. These should be glued together.
          > > Then use some brass (if at all possible rather than wood//styrene
          > > although wood could be used) whose thickness is the same diameter as the
          > > trolley wire. These are the end pieces on either side of the gap and
          > > can be glued in place to allow the contact wire to pass between the gap
          > > and the brass so leave enough spacing between the two for the wire.
          > > ALSO, glue it in place so it sits higher in the insulator by the
          > > thickness of the wire.

          > REVISING the last sentence:: ALSO, glue the brass in place so it sits
          > higher than the runner gap by the diameter of the trolley wire.

          > > The contact wire will come in under the brass, be bent to pass up
          > > between the brass and the gap, and bent back on top to stay in place.
          > > If at all possible, tack solder the wire to the outer end of the brass
          > > on either side of the insulator.

          > When the trolleywire comes in under the brass, it will be perfectly
          > flush with the runner-gap for smooth passage of the shoe.

          > > This should keep the contact wire flush with the gap for smooth
          > > passage. Tack soldering to the brass prevents the wire from sitting
          > > beside the brass and causing a snag with a pan or dewirement with a
          > > pole.

          > This is also why it is better to use brass than wood so it is possible
          > to tack solder. I know - this will be difficult!!

          > An alternative is to glue a piece of contact wire between the side
          > sills near the runner-gap for passage of the contact wire between the
          > runner and this wire. Glue it in so that it forces the incoming contact
          > wire to be flush with the gap. Also make sure that the contact wire
          > stays clear of any insulator overhang to prevent dewirement.

          > > Cut off any excess and shape the top to make it look acceptable.

          James B. Holland

          Pittsburgh Railways Company (PRCo), 1930 -- 1950
          To e-mail privately, please click here: mailto:pghpcc@...
          N.M.R.A. Life member #2190; http://www.mcs.net:80/~weyand/nmra/
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