Disputes quickly erupted over how to divide responsibilities. Some executives appeared not to fully grasp how little money they had to complete a complex project with a tight deadline and a multicultural team whose members did not always see things the same way. ... Internal arguments soon gave way to bigger problems. There would be work stoppages, porous concrete, a risk of earthquakes and at least $3.4 billion in disputed costs: more than the budget for the entire project. ... Seven years later, and nearly two years late, the locks have finally been declared ready to accept the new generation of giant ships that carry much of the world’s cargo but cannot fit in the original canal. To mark the occasion, Panama has invited 70 heads of state to watch on Sunday as a Chinese container ship becomes the first commercial vessel to attempt the passage from the Atlantic Ocean to the Pacific through the larger locks. ... For more than 100 years, the canal has been a vital artery nourishing the world economy, a testament to American engineering and one of the signature public works of the 20th century. The new locks, built by Panama without help from other governments, were sold to the nation and the world as a way to ensure that the canal remained as much of a lifeline in the hyperglobalized 21st century as it was in the last. ... one inescapable fact will remain: The expanded canal’s future is cloudy at best, its safety, quality of construction and economic viability in doubt ... In simple terms, to be successful, the new canal needs enough water, durable concrete and locks big enough to safely accommodate the larger ships. On all three counts, it has failed to meet expectations, according to dozens of interviews with contractors, canal workers, maritime experts and diplomats, as well as a review of public and internal records.