Transit City wanted to get rid of the SRT because it was an orphan technology.
So, they brought in a new orphan technology in LRT that was designed in such a way that the streetcar could have sufficed.
When people say orphan technology in the context of the SRT they mean it was the only line in Toronto that used ICTS trains and the city had no plans on building any new ones.
The SRT and LRT might be "orphan technologies" for Toronto (I'm not sure this is true, at least not with the line 5 Flexities), but that's not really what the phrase means when used in discussions like this. It refers to vehicles that are bespoke and customly made for only one or two customers, and as they age parts become difficult to source. A good example of a genuine orphan technology was the CLRV/ALRV cars, parts were hard to come by and they had to manufacture a lot of them in house towards the end.
In comparison, lots of cities across the globe have bought similar trams as run on our LRT network, and that is precisely why they are
not orphan technologies - the manufacturers will keep making parts for them for a long time, and maintaining them in the long run won't be a problem.
The ICTS technology of the SRT, for this reason, also doesn't qualify as orphan tech. Other cities use it, a place like Vancouver to quite a substantial extent. If we wanted to keep the SRT going, parts available wouldn't have been an issue. They wanted to get rid of it because a) it was old and failing, b) buying new cars would have required the reworking of the tunnel at Ellesmere, c) its route was of highly dubious value, and d) the tech didn't play nice in Toronto winters.
Danger" is the wrong word here,
There is no need to take my word choice so literally. "There's no danger of XYZ" is
very common parlance in English and seldom refers to things actually being dangerous.
it would be an operational advantage if it were possible, despite the distance between them. I imagine a north/south connecting track between them akin to the track on Bathurst tying the 512 to the rest of the 500s, and the 512 is also quite out of place compared to the rest. Had L5 & L6 been designed as part of the 5XX network, and had track connections both to each other and to the 5XX (L5 to 512 is the same distance as, or less than, 512 to 5XX), it would've still been more sensible than having 2 standalone lines.
Except that comparing the distance from Eglinton to SSt. Clair is inaccurate, as there is no maintenance facility on St. Clair. So to be accurate, you need to calculate the distance from Leslie, Russell, and Roncesvalles to Eglinton or Finch. For some perspective, the deadhead time from Leslie to Spadina Avenue is already around 40 minutes, just how long would such a journey take if they were driving a streetcar that had to run in mixed traffic
already to get all the way to Finch? It's 12 km from St. Clair to Finch, that is not a small amount of trackage to keep only for yard movements. To achieve operational efficiency, you'd need to construct a carhouse on Finch
anyway, and therefore no advantage is gained from this so-called interoperability. Finch to Eglinton is not much better, it's 8 km between the two. If you're building that much trackage, you might as well implement rail service on that street... except that Eglinton, and Finch are not logical end points for a rail service along Bathurst Street, and much of Bathurst is too narrow to build a private ROW.
For comparison, the distance between the 512 and the northernmost east-west streetcar route, the 506, is only 3.04 km. That is a
completely different scale we're talking about here.