Slim employed Billy Williams and his corps of elephants, led by Bandoola, to build bridges and rescue refugees. He faced the same problems that the Japanese had faced in their failed 1944 offensive in the opposite direction. He made the supply of his armies the central issue in the plan of the campaign. The Chindwin River was spanned with the longest Bailey bridge in the world at the time. To distract the Japanese from his campaign in central and southern Burma, Slim ordered the Chinese in northern Burma to begin an offensive, which for a time led the Japanese to the erroneous conclusion that the main goal of the Allies was to open the Burma Road to China. Slim began his advance by sending two corps towards Mandalay and another corps along the coast towards Rangoon, but changed his plans when he learned from intelligence that the Japanese were planning on defending Mandalay from the eastern banks of the Irrawaddy River. Slim had one corps cross the Irrawaddy south of Mandalay at Meiktila while another corps staged a feint attack on Mandalay from the north to distract the Japanese from the main blow coming up from the south. The swift flowing Irrawaddy is a wider river than the Rhine, making it into a natural defensive barrier that the Japanese believed could halt the British advance. However, much of the countryside around the Irrawaddy consists of plains that favoured the offensive, and in his operations in the Irrawaddy river valley, Slim used combined arms offensives with artillery and tanks working closely with the infantry to bring down overwhelming firepower when the Japanese tried to block the British 14th Army's advance. In March 1945, after crossing the Irrawaddy, the town of Meiktila was taken, followed by Burma's second city, Mandalay.