Panama ? President Martin Torrijos announced plans Monday night for the biggest expansion of the Panama Canal since it opened in 1914, making way for huge new container ships that can carry twice as much cargo.

The project calls for the construction of a third set of locks of water chambers that will allow the large “Post-Panamax” class of cargo ships to use the 50-mile waterway between the Atlantic and the Pacific oceans.

Alberto Aleman Zubieta, administrator of the Canal, said the cost of the expansion would be about $5.3 billion but the expansion was “necessary, convenient and economically sound.”

Torrijos said information on the canal expansion project will be made available to the public to spark a long debate before the issue is put to the voters in a national referendum expected later this year.

The cost of the construction would be financed through Canal fees and some bank investments without risking government social programs, he said.