A $50 million rail project, which will rehab tracks, reconstruct a rail bridge and improve links from the port to the FEC rail yard near Miami International Airport, is expected to be completed by next summer. The port is devoting 15 acres to build three parallel rail tracks that will allow half-mile-long trains.

“The local markets aren’t big enough to support what is coming off the vessels,’’ said Kevin Lynskey, assistant port director for business initiatives. “A big ship needs the rail link to make their economies work.”

When the rail projects are finished, “we’ll be able to connect with 70 to 78 percent of the American population by rail,’’ said Johnson, the PortMiami director. “Without rail, what does the deep dredge mean? Zero.’’

Ditto for the $915 million port tunnel. “If you want to stagnate in 2015, you don’t build a tunnel,’’ Johnson said.

Without any of the $2 billion in upgrades that are in the works, he said Miami would have to content itself with being a small regional port.

With Miami’s three-pronged attack — tunnel, rail, and dredging — the port claims it will be able to make inroads into some of the markets that Savannah now dominates.

A brochure prepared by PortMiami claims that after a three-day trip from Panama, it can have cargo in Atlanta in two additional days and in Memphis in three more days using a Florida East Coast rail connection.

While a ship takes 1½ days more to reach Savannah than Miami, Foltz points out the Atlanta market is just four hours away by truck.

“Reaching into our market? Good luck. That’s a stretch,’’ said Savannah’s Foltz. “We’re getting cargo destined for Orlando and Tampa now.’’

“Savannah is not going to sit idly by and let anyone take away its northern Europe and Asia business,’’ said John Martin, a Pennsylvania-based port consultant who has advised most major U.S. ports. “Savannah is an excellent port.’’

But he’s also bullish on Miami. Having its three major projects come together more or less at the same time is a “major grand-slam homerun,’’ he said. It puts Miami in a position to become a gateway port, win back its trans-shipment business, and become a distribution hub.

Plus, he said, with the trend toward near-sourcing — sourcing manufactured products in Mexico and Central and South America because of rising labor costs in China and mounting Asian transportation costs due to high fuel prices — both Miami and Port Everglades are well-positioned to capture North-South trade.

So which ports are the front-runners when the big ships begin transiting the canal?

Experts shy away from the question, but they do say it’s not simply a matter of dig a deep enough shipping channel and the big ships will come.

The port, its rail connections, trucking networks, distribution channels and the entire logistics chain needs to be analyzed and there are ripple effects all along the way. If a factory needs imported parts and supply routes for those parts are better elsewhere, it might just pick up and relocate.

Pricing, the degree of bureaucracy, security, labor peace, and the ease of getting products through customs also play into shippers’ decisions to use a particular port. So does proximity to certain products. That’s why Savannah’s main exports are forest products, kaolin clay from Central Georgia, cotton, chemicals and poultry.