Sliding gates often fail to open or close because debris blocks the track, wheels slip off the rail

https://donovanjqcf109.trexgame.net/why-iron-gates-sag-and-how-welding-can-reinforce-cracked-or-weak-sections

Sliding gates often fail to open or close because debris blocks the track, wheels slip off the rail, tracks shift out of line, or the operator needs a reset after an obstruction is cleared.