The giant machines that will bore a train tunnel beneath the Hudson River connecting Manhattan to New Jersey are being assembled. The $16 billion tunnel is one of the largest and costliest mass transit projects in modern U.S. history. It was briefly halted over the winter, when President Donald Trump froze funding. But a federal judge in February ordered the administration to release the money, allowing work to resume. When complete, the project with four modern rail tracks between New Jersey and New York where there are currently only two.