The problem, as with many comparisons, is the lack of matching information
about the things you're comparing. You can get certain stats about one and
an overlapping set of other stats about the other, but not a common set for
both. I would like to know what would be the current draw on acceleration
of a Skoda 15T or a set of Tatra T3s. The only clue I ever got is when I
asked once whether the fast acceleration of Prague trams resulted in higher
operating costs and was told that the difference was so tiny they stopped
measuring it years ago, so that suggests it's not a big issue for them and
they often have multiple trams accelerating together with their stops
holding two trams. Yet it's an issue in Melbourne?

Tony P

On Monday, 15 August 2022 at 10:32:05 UTC+10 Mal Rowe wrote:

> On 15/08/2022 09:53,peterm...@... wrote:

> > 1500A on a 600V overhead, is not good in terms of voltage drop. Ive

> > not been to Melbourne for a while, is it still a single contact wire,

> > or are there dual contact wires and additional feeder wires like

> > railway approach to reduce voltage drop?

> >

> There are multiple feeder cables throughout the system and no places

> that I am aware of where there is noticable voltage drop.

>

> I was told at a safety briefing by Yarra that the trip current from a

> substation is usually set at 2500A - meaning that up to 5000A is

> available in a typical section fed from both ends.

>

> There are no double contact wires that I am aware of, but there are

> places where an extra set of contact wires is hung on the overhead as

> feeders. You can see them in my pic at: https://tdu.to/i/52233

>

> The light rail lines to St Kilda and Port Melbourne still have the

> heavier contact wire and catenary from railway days.

>

> See my pic at: https://tdu.to/i/39803

>

> Mal Rowe - who once knew a bit about Elec Eng

>

>

>

>