Home/American Shipper/PO Shipping stays in TP, while T.S. Lines exits American Shipper PO Shipping stays in TP, while T.S. Lines exits FreightWaves Staff · Friday, January 20, 2012 The China-based liner carrier PO Shipping will continue to serve the transpacific trade to Southern California, although its former partner Taiwan-based T.S. Lines has bowed out.