TNT Duping Quarry

everytime i run our tnt flying machine, and the machine goes out of render distance, once i come close enough to render the machine, the minecarts clip out. I have tried to read up on some mechanics, but got no luck. I tried recreating the issue in a singleplayer environment but upto no accord. Can someone pls enlighten me? my server is trying to make a perimeter for a witch farm, it would help a lot!