01-04-2026, 01:24 PM
After exploring the differences between my new Rapido locomotive versus everything else on my roster, and after running virtually every locomotive I have through Mud Run Curve (none other than the new one derailed), as well as running the newby in every speed in every orientation through the curve (forward, backward, downgrade, upgrade), I came to one conclusion. If I want to keep the M420, there will have to be some changes made..... and those changes are all about superelevation (or track cant) in Mud Run Curve. Found a good article on it in Wikipedia.... Cant (road and rail) - Wikipedia
It seems that the overall stiffness (side to side) of this model means that at some points navigating the curve, only 7 of the eight wheels are maintaining contact with the rail. On a tight curve, that just doesn't work - that one wheel causes havoc and causes a derailment. Add in a front plow, some low steps, and gear housings that drop low toward track ties.... it was a test of my patience figuring out a solution, with the nirvana moment encountered while pushing the rear of the locomotive through from the beginning of each portion of each curve and monitoring how well each wheel was maintaining contact with each rail. For a portion of my layout that's been completed for at least 2 years (and replete with trees and lots of other scenery) it was a challenge.
I spent some time with a flat-ended cat's paw gently prying up the outer edge of my roadbed around major portions of Mud Run Curve to induce superelevation of the outside rail, and I did have more success running the locomotive through the curve running upgrade. However, in running downgrade and attempting to modify the superelevation, some of the portion of the track on the northern half of the curve have now delaminated from the roadbed and the ballast is a mess. After making a mess, the decision has been made! Not only am I keeping my new locomotive, there's going to be a track redo in Mud Run curve! Just goes to show you that even if you think a portion of your layout is bulletproof, you need an asterisk next to it... After the track redo there will also by necessity be a scenery touchup and a reballast required. Happy New Year!
Due to this unscheduled maintenance action in the gorge, most of my White Haven town projects will have to be put on the back burner I think.
It seems that the overall stiffness (side to side) of this model means that at some points navigating the curve, only 7 of the eight wheels are maintaining contact with the rail. On a tight curve, that just doesn't work - that one wheel causes havoc and causes a derailment. Add in a front plow, some low steps, and gear housings that drop low toward track ties.... it was a test of my patience figuring out a solution, with the nirvana moment encountered while pushing the rear of the locomotive through from the beginning of each portion of each curve and monitoring how well each wheel was maintaining contact with each rail. For a portion of my layout that's been completed for at least 2 years (and replete with trees and lots of other scenery) it was a challenge.
I spent some time with a flat-ended cat's paw gently prying up the outer edge of my roadbed around major portions of Mud Run Curve to induce superelevation of the outside rail, and I did have more success running the locomotive through the curve running upgrade. However, in running downgrade and attempting to modify the superelevation, some of the portion of the track on the northern half of the curve have now delaminated from the roadbed and the ballast is a mess. After making a mess, the decision has been made! Not only am I keeping my new locomotive, there's going to be a track redo in Mud Run curve! Just goes to show you that even if you think a portion of your layout is bulletproof, you need an asterisk next to it... After the track redo there will also by necessity be a scenery touchup and a reballast required. Happy New Year!
Due to this unscheduled maintenance action in the gorge, most of my White Haven town projects will have to be put on the back burner I think.
Check out my "Rainbows in the Gorge" website: http://morristhemoosetm.wixsite.com/rainbows