Background - I am building around the walls, HO scale, shelf at arm-pit height, 30" curves on a single track mainline. I just finished superelevation on two of the inside corner mainline curves and they look pretty cool.
Question - I will next lay a passing siding parallel inside the mainline curve. Would this track have superelevation also or be laid flat? In other words, is prototype superelevation only used for mainline trains traveling at speed or used on other curves also?
Normally if trains are going to be stopped or moving slow through the siding, then there is no need for superelevation(expense to maintain). Also with extreme superelevation, a slow moving or stopped train is putting a lot of force on the inside rail.
Now, it is your model railroad - If you think it is ‘cool’ looking, then go for it!
Depends on location, traffic density and type of traffic. I recall a particular derailment prone industrial curve, where the Asst. Division Engineer replaced the outside rail with heavier rail to create about an inch of superelevation, in an effort to eliminate the derailment problem. - the idea didn’t work. Train involved was a unit grain train. Ultimately, the branch was rebuilt, with superelevation built into the “problem” curve, and the derailments stopped. About one year later, the plant closed and the unit trains also stopped …
If the siding is used as a passing siding for main line trains it should be built to the same standard as the main track. If the siding is used to store cars or as a switching lead, it doesn’t need to be superelevated.
Prototype railroads have specific policies depending on usage and need. So do model railroads. It’s your call.