So put a tram in with high mileage, already breaking down with no spares available other then what is available on other variotrams and absolutely no relevance to Melbourne. A tram that was designed for a 750v system and would fail almost immediately on Melbourne's legacy tram network.
Yes a real good point.
No spares in Australia. The same could be said for the 5 Citadis bought from Mulhouse.
Chemnitz has around 30 Variotrams almost identical to Sydney's. Manheim has nearly 100 trams that while mechanically quite different run the same traction converter package. Parts would be available from Germany for the Varios still. Parts for the Citadis would be coming from France anyway.
Mechanically a Variotram is very simple. The complexity is in the computers/software they run and that's common across the entire family. Pyrmont was getting things like motor overhauls for the Variotrams done locally, they were not sending them back to Germany for example. The same motor works did motors for Melbourne trams and trains.
Really the Vario's were put up for sale after Melbourne started getting E class delivered, why would Melbourne acquire someone else orphans when they had new state-of-the-art trams already arriving?
Had they been for sale back when Melbourne was considering the Mulhouse Citadis, they may very well have been relocated to Melbourne.
Adelaide made the decision when getting the Flexity of the Frankfurt am Main type to go to a 2.4m wide vehicle, the Sydney Varios are too wide.
As for preservation of a Vario, 2107 is officially set-aside, but the actual details are STILL a work in progress.
BTW the 600/750 problem isn't for a Vario - the traction package is designed to operate down to 450v. The Sydney ones were programmed to automatically derate between 500 and 600v to limit current draw. After 600v full power was available. The traction motors are designed to be able to run at full rated power on 450v and normally run at that voltage in 'power' mode (when in braking mode, the voltage can get much higher).
The traction package can even cope with a -750v system and has the option (not fitted to Sydney trams) to switch from +600 to -750v on the fly without needing to stop. (This feature was required in Mannheim/Heidelberg in Germany)
The 'vario' bit in the type name was intended to convey that the platform could work in a variety of circumstances and was flexible enough to 'vary' it's operating parameters on the fly.