How I inspect and test track work in Trainz

[JonMyrlennBailey]

I've just super-elevated my cloned Avery-Drexel route. However, I've noticed wonky train behavior at some super-elevated track points. The train underway would suddenly snap from a leaning position to an upright position, vice-versa, at certain super-elevated points as 5 degrees. I have investigated and found out this undesirable behavior is often occurring at super-elevated points near a switch lever or a straight section of track shorter than a locomotive that is in the middle of an S curve. Super-elevating a straight piece of track with curves at either end in opposite directions has a twisting effect on it. Like a peppermint twist candy stick. I can get away with super-elevating such short section of straight track at both its endpoints, a segment, if the curve leading into it is the same direction as the curve out of it. That is if the train is bending to the left upon approaching the short straight section of track, the train continues to turn left following the short straight section. However, if the train turns left into a short straight section of track with super-elevated pouts at either end but turns right coming out of it, the train will suddenly snap from a lean to an upright position or vice versa. Train behavior will be wonky if one doesn't pay close attention to track geometry in Surveyor. I use an engine such as the UP SD40 for track testing and inspection. The Amtrak MOW Truck is not the best test vehicle for this due to very short wheelbase and in-cab camera behavior that is overly sensitive with this type of "loco" content.

 

[mapsgame]

Good methodology for checking superelevation.
Rail and road superelevated horizontal curve design uses two methods for the transition from level tangent to curves with superelevation -- 1) runout or 2) spiral curves with super elevation. The 2003 AREMA, Chapter 6 Railroad Track Design, pg. 224: "The transition from level track on tangents to curves can be accomplished in two ways. For low speed tracks with minimum superelevation, which is commonly found in yards and industry tracks, the superelevation is run-out before and after the curve, or through the beginning of the curve if space prevents the latter. A commonly used value for this run-out is 31-feet per half inch of superelevation. On main tracks, it is preferred to establish the transition from tangent level track and curved superelevated track by the use of a spiral or easement curve. A spiral is a curve whose degree of curve varies exponentially from infinity (tangent) to the degree of the body curve. The spiral completes two functions, including the gradual introduction of superelevation as well as guiding the railway vehicle from tangent track to curved track. Without it, there would be very high lateral dynamic load acting on the first portion of the curve and the first portion of tangent past the curve due to the sudden introduction and removal of centrifugal forces associated with the body curve."

How short is the tangent section you have? Short tangents <or= to the length of the longest length of rolling stock should cause a jerking effect especially on reverse curves due to shifting the super from one rail to the other in a short distance. A longer tangent should help to avoid the jerking. Trainz doesn't have spiral curves so the runout method for beginning and ending super on curves is the best we can do.

Have you been able to elevate only one end of one rail on a tangent section?