In a semiconductor fabrication facility, a conveyor transports substrate carriers. The substrate carriers are unloaded from the conveyor and loaded onto the conveyor without stopping the conveyor. A load and/or unload mechanism lifts the substrate carriers from the conveyor during unloading operations, while matching the horizontal speed of the conveyor. Similarly, during loading operations, the load/unload mechanism lowers a substrate carrier into engagement with the conveyor while matching the horizontal speed of the conveyor. Individual substrates, without carriers, may be similarly loaded and/or unloaded from a conveyor.