02-21-2017, 05:53 PM
(02-21-2017, 05:26 PM)timc Wrote: Last time this talk came around, someone said it takes less space to build two side platforms than it does to build one centre platform with tracks on either side.
And, if the schedule has variations throughout the day, then might there be overlap during transitional times where there are two trains at the platform?
In our minds, we can imagine a center platform with rails on either side or a central rail pair with platforms on either side as being relatively similar in size. The issue would likely be once you get out of that area. If you have central rails, they are already at the correct spacing right outside of the platform area, and you can drop in a standard crossover. If you have central platform, then you need to travel a certain distance before the outside rails can get close enough to each other to be at the correct rail-to-rail distance. At that point you can drop a crossover down, but you have chewed up extra side space leading up to that point from the rails having to come back together, and extra length because they need to come back together before you can drop in the crossover before you can start to have the rails turn. Both the extra width and extra distance before you could have the rails turn (in this case, to S-turn over onto King Street) would likely be why we have a rails-in-center platform at this location.