From the
CROR
Dual Control Switch
A switch equipped for powered and hand operation
Power-operated Switch
A switch equipped for powered operation, but not hand operation
Main Track Hand Operated Switch
A switch connected to the main track used to route equipment or a track unit to or from the main track.
(in railway space, a "main track" is a whole different proposition than yard trackage and a main track switch has a whole set of rules of its own)
Electric Switch Lock
An electric lock connected with a hand operated switch to prevent its operation until the lock is released
(Even more rules to follow if a switch has an electric lock)
Without getting too far into the rules, passenger train crew regularly operate switches out on the mainline in signalled territory under direction from the RTC. This may happen due to signal failure, or because of maintenance of way activity, or because the signal circuitry won't allow the RTC to align the route desired in some unusual situation.
As to designing the trackwork, one does not simply plunk in a power switch like one does on an HO layout (which isn't always easy, either). There is a whole set of considerations including cost, impact on the surrounding signalling and circuitry, and frequency of use. Adding a switch may change how the rules work in that location, creating complications for other trains in the general area, and adding work for the RTC. Five or ten minutes of effort by the train crew and RTC a few times a week may be much simpler for the railway than complicating the plant.
Moncton VIA is a good example of how much the rail infrastructure has changed over the years. The railways have removed every extraneous switch, siding, and signal that no longer serves any function. If you assume that because a passenger train once ran someplace, it can be reinstated, you are missing an important point. Moncton is a good example of a once elaborate rail center that has been stripped down to bare minimum.
- Paul