The Alliance Pipeline System consists of four system sections known as the Canadian Interconnect Pipeline System, Canadian Lateral Pipeline System, Canadian and US Mainline Pipeline System, and US Delivery Pipeline System. The Canadian portion of the system consists of 339 km (211 miles) of 1067 mm (42 inch) and 1220 km (758 miles) of 914 mm (36 inch) diameter steel pipe. The United States portion of the system consists of 888 miles (1429 km) of 36 inch (914 mm) diameter steel pipe. The 36 inch mainline section from Windfall, Alberta to the Aux Sable Meter Station in Illinois has an outside diameter of 914 mm (36 inch) and has a Maximum Operating Pressure (MOP) of 12000 kPa (1740 psi). The line speed ranges from 7 to 9 meters/second (15.6 to 20.1 miles per hour) and the nominal pipe wall thickness ranges from 14.2 mm to 22.7 mm (0.560 to 0.895 inch). The pipeline is also internally lined with liquid epoxy for flow enhancement applied to a thickness of 2 mils (51 microns). Alliance's commitment to ensure integrity management of the pipeline has extended to a baseline metal loss inspection of the system to assist in developing and optimizing future programs. This paper will outline the issues faced by the operator in evaluating tools that have been designed and are commercially available for a gas pipeline system requiring speed control and high magnetic saturation for heavy wall pipe. The paper will also describe the process followed by the pipeline inspection vendor including tests performed before the inspection as well the mechanical, electronic and magnetic challenges the inspection vendor had to overcome to ensure a successful inspection.