A mega tunnel boring machine known as Jianghai – meaning river and ocean – reached a depth of 75 meters under the Yangtze River on May 3. This is the lowest point recorded in underwater shield tunneling to date. The machine is being used in the development of the Haimen-Taicang highway in east China's Jiangsu Province. Around a third of the 39-kilometer-long project runs under the Yangtze River. It's the world's longest underwater highway tunneling project.