How to make a infinitely looping payload track?

[The Pansmith™]

How would one make a payload track w/ a payload on it that would loop, without any form of timer.
I trying to make a idle/trade map, but when I attempt to preform this, TF2 crashes.

Thank you in advance

 

[Werewolf]

If your map is crashing, it probably for some other reason.

Post your compile log

 

[henke37]

The trainwatcher follows the track. If there is a loop in the track, then the watcher gets caught in it. And this leads to the game hanging.