A trailing pig cleaning device is adapted to be dragged by a pig towing device. The cleaning device collects a predetermined quantity of debris. The cleaning device has a continuous outer surface portion of variable diameter urged into normal contact with the internal wall of the pipeline. The continuous outer surface portion presents a continuous upstream or leading edge portion for scraping debris from the cylindrical internal wall in advance of the outer surface portion. The device has a debris collecting surface portion extending radially inward from the outer surface portion for collecting the predetermined quantity of debris scraped from the cylindrical internal wall. The device has at least one debris and pipeline media bypass opening passing through the debris collecting surface portion permitting excess scraped debris to pass therethrough back into the pipeline and permitting media to pass thereby to propel the pig towing device.