|View single post by Tramcar Trev|
|Posted: Mon Apr 1st, 2013 10:09 pm||
|I have learned quite a bit today.
1) Variable focus glasses are a waste of time when doing fine work; yes it’s taken me till now to work that out! From here on I’ll take the magnifying lamp out with me…
2) Plastic overhead fittings do not make the grade, my nifty little plastic Section Isolator, herein after referred to its common name of a “Cut Off’ broke the instant I tried to put some tension on it..
So lessons learned I made a new cut off and used some stainless steel that I scrounged from the stuff that stiffens windscreen wiper blades; I just knew I would have a use for it. It’s still a “copy’ of the really old type that was made from porcelain way back when trams were just hitting the period of electrification. I had some nice pictures in an old catalogue (which of course I cant find now) basically a U shaped length of porcelain upside down so the trolley wheel ran inside it, the trolley wire went up through a hole and was terminated so that the 2 sections of wire were insulated by the porcelain. They were not particularly successful; the porcelain proved too fragile and had poor tensile strength. There is only one of these in the LVET to separate the eastern and western sections and I’ve substituted the porcelain with a plastic channel. I’m not actually sure what is going to happen when in use, as the Pulse Width Modulated controllers seem to modulate the negative supply so as the trams have at least 4 wheels the 2 sections will be “joined” while the car passes over the joint, marked by a marble strip between the rails. This as we have discussed before is a hang over from the days of cable trams where marble strips gave the Gripman a visual clue when to drop the cable. They eventually were all replaced with signs suspended from the overhead. Sydney Light Rail has the word “Coast” on signs where they don’t want current drawn….
Anyway it’s another major milestone getting the overhead work started on the Eastern Section. Enough ears (made in WA while I was touring) are in position to support the wire; more will have to be placed to hold the trolley wire central over the bends. Some of the span wires may appear slack too, simply because there is no trolley wire there to provide some tension….
I decided after much agonizing that I would not solder any of the support wires as it would make repairs difficult, and I’m sure repairs and adjustments will be essential.
Pictures are on my blog as well as the sordid detail as to how I made my ears and other fittings....
There once was a man who said Damn!!
I perceive with regret that I am
A creature that moves
in predestinate groves
I'm not a Bus, I'm a tram