(07-22-2021, 04:58 PM)taylortbb Wrote: The on-street sections aren't generally done with railroad ties and ballast, so it's not just throwing some dirt on top. Even if you did throw dirt on top of the ballasted track, that would totally eliminate the ability inspect things, like any of the clips used to fasten the rails to the ties. There's some actual engineering involved here.
The construction of the embedded track is actually quite simple. They built it all in one layer here, rather than the two layer approach Toronto uses. It's basically just booting the rails, holding them in place, and then pouring concrete around them. Having to create space for soil would mean more formwork, and after that it's not as simple as "throw some dirt and seed down" if you want to it to look any good. Especially with the amount of salt that would end up on it being part of the roadway.
The upfront cost might not be that much more, but the maintenance certainly would be.
Yeah I know how it was constructed, I remember seeing it all.
To achieve green railroad tracks as we're discussing, you can achieve it in a few ways. The most common is simply to use ballastless track, which is what is used in things like subway tunnels. There are numerous ways of constructing it depending on what you require, but essentially the track sits on a concrete bed (buried well below the track itself) and then the track is affixed to smaller railroad "ties". If you look closely at this photo you can see what I mean. Then, you can simply cover that lower layer of concrete with soil and grass. If extra drainage is required, holes can be made in that lower layer of concrete, though in most cases ballastless track has superior drainage to begin with.. Maintenance should not really be an issue, because in fact, ballastless track tends to require far less maintenance than normal tracks. You can still inspect the track where needed, but overall the maintenance is lessened. Initial construction may cost more, but overall costs should be less in the long term as there is less repair work necessary. This sort of construction also improves vibration impacts, which is a really important thing, especially when you're running a surface level train in the middle of a dense urban area.
Alternatively, you can just use normal concrete ties and then fill those over with soil and grass. This photo shows an example of concrete ties sitting on gravel ballast, but to add soil over that should not be a real challenge.
Ultimately, I guess the region just didn't want to spend the money doing something like this. The ION is basically a dollar store LRT. But anyway, this is more infrastructure related and not on topic for this thread.