Final Midtown segment sunk

摘要

Engineers on the new Midtown Tunnel, which crosses the main channel of the Elizabeth River in Virginia (US), sunk the final segment on July 14. There are 11 segments on the immersed tunnel, each weighing 16,000t. The segments were built in a dry dock in Sparrows Point, Maryland, and floated 220 miles down the Chesapeake Bay to Portsmouth, where they were stored at the Portsmouth Marine Terminal. After dredging the river and preparing the foundation with sand, construction crews began submerging the structures into the river with a lay barge, which assists in anchoring the large pieces into the river.