The Zhoushan Island Overhead Powerline Tie is a 220 kV three-phase AC interconnection of the power grid of Zhoushan Island with that of the Chinese mainland. It runs over several islands and consists of several long distance spans, the longest with a length of 2.7 kilometres (1.7 mi) south of Damao Island. This span uses two 370-metre-tall (1,210 ft) pylons, which were the highest electricity pylons in the world, until 500kV line to Zhoushan from mainland was completed. The north tower on Damao Island (Chinese: 大猫岛, dà māo dǎo) was completed in 2009, and the south tower on Liangmao Island (Chinese: 凉帽岛, liángmào dǎo) was completed in 2010. These pylons resemble those of the Messina Strait, but are steel-tube lattice structures.[1]