Re: Re: Newcastle tramway video
  Alex Cowie

Richard,
In the photo of the French design, the attachments of the crossarms to the
vertical member look like hinged joints. The vertical member rigidly
attached to the curved cantilever arm and the main mast effectively provide
the same attachment points for the crossbars and their support stays as the
centre poles in the Parkwood photo. Thus the French and Gold Coast
installations provide similar independent support for the contact wires.

For some reason although the Parkwood photo is present when viewing in the
Google Groups web interface and in the email version of your post, it has
been replaced in your post in the TDU archive by a short Google Groups text
file!

Alex C

On Monday, February 11, 2019 at 8:24:17 PM UTC+10:30, Richard Youl wrote:
>

> All Of those look more attractive than the construction shown this

> morning. I have reproduced it below for anyone who may have forgotten.

>

> A closer look reveals that it is not a structure for catenary. The section

> of double wire on the right is only brief and probably is where a new wire

> comes in and the other ends. There is certainly no catenary on the closer

> track.

>

> For comparison I took a photograph at Parkwood East today, the second

> image below.

>

> I think this looks less intrusive than the French design which no doubt is

> intended to be stylish. The crossarms of the first mast include feeder

> wires coming from underground whereas the second mast is standard and is 40

> m away, the standard mast spacing. Note the thinner pipe used in the top

> half.

>

> One feature of best design overhead is that the wires for the two tracks

> should be as independent as possible from each other so that if a

> pantograph or anything else snags the overhead, the wire for the second

> track is very much less damaged, or better still escapes damage.

>

> The Gold Coast support arms are attached by hinged pivots and a pantograph

> damaging one wire should have little affect on the other. It’s debatable

> whether this isolation is adequately designed into the ‘stylish’ French

> equipment.

>

> Richard