A busy scene on the construction site of the Pearl River Estuary Tunnel of the Shenzhen-Jiangmen High-speed Railway, a major transportation project in the Guangdong-Hong Kong-Macao Greater Bay Area. The “Shenjiang No. 1,” the tunnel boring machine assisting the tunnel construction, made history yesterday by delving 106 meters below the sea surface, a new record for China’s shield tunneling depth and for the world’s deepest subsea shield tunneling for high-speed railways. Once the project is completed, Chinese high-speed trains will be able to travel over 100 meters beneath the sea.China Central Television