2016-2020

China builds the longest undersea tunnel in the world

China's latest megaproject is a 76 mile (122 km) undersea tunnel running from Dalian to Yantai. It surpasses the combined length of the world's two longest undersea tunnels – Japan's Seikan Tunnel and the Channel Tunnel between Britain and France. With previous journeys cut by 800 miles, it forms a vital high-speed rail link between the north and south of the country, boosting economic growth significantly.
This $36 billion project is constructed in less than five years.* It is actually three parallel tunnels – one for cars, one for trains and one for maintenance, placed 100 ft below the sea bed. Vertical shafts are located on island stepping stones to provide ventilation. However, there is much controversy surrounding the route, which passes over two major earthquake fault lines.*

2016

Completion of the Panama Canal expansion project

Built from 1881 until 1914, the Panama Canal was among the largest and most difficult engineering projects ever undertaken. Functioning as a short cut between the Atlantic and Pacific Oceans, it greatly reduced the travel times for ships – enabling them to avoid the lengthy, hazardous Cape Horn route around the southernmost tip of South America.
For nearly a hundred years, the canal enjoyed great success, acting as a key conduit for international maritime trade. By the early 21st century, however, it was handling far more vessel traffic than had ever been envisioned by its builders. In 1934, it was estimated that the maximum capacity of the canal would be around 80 million tons per year. In 2010, the actual figure was nearly 300 million tons and growing rapidly, with over a third of shipping traffic unable to pass through because of size. Global demand necessitated a major upgrade.
Plans were formulated for various improvements – including the excavation of new traffic lanes allowing more and larger ships to transit; two new locks, one each on the Atlantic and Pacific sides; the widening and deepening of existing channels; and the raising of Gatun Lake's maximum operating level. Construction was originally slated to take seven or eight years, with new locks beginning operations in late 2014, almost exactly a century after the canal first opened. In 2012, however, it was announced that the expansion project had fallen six months behind schedule, pushing the opening date back to April 2015. Further delays were reported in September 2014.
In early 2016, construction is finally completed and the new gates are open for transit.* Capacity has now been doubled, allowing the canal as a whole to handle the projected rise in volume to 2025 and beyond. This mega-project eases numerous burdens on the shipping industry, as well as creating huge numbers of jobs among the Panamanian people – generating enough wealth to reduce poverty in the country by almost 30%. However, critics of the project contend that there are serious environmental issues.

Map of the Panama Canal expansion project in 2016. Credit: PanCanal.