The China Mail - Port blocked by Baltimore bridge collapse is key hub for US shipping

Its nighttime collapse, within seconds of being struck by a container ship, is likely to cause substantial economic damage for as long as it continues to force the closure of the Port of Baltimore.

The bridge's collapse blocked access to the port for all shipping traffic, which last year carried more than 52 million tons of foreign cargo, worth some $80 billion, according to a recent statement from Maryland Governor Wes Moore's office.

Baltimore is the deepest harbor in Maryland's Chesapeake Bay, and handles the highest volume of autos and light trucks in the United States, as well as the largest quantities of imported sugar and gypsum.

The Port of Baltimore is the ninth-busiest major US port in terms of both foreign cargo handled and foreign cargo value, and is directly responsible for more than 15,000 jobs, supporting almost 140,000 more.

It generates around $3.3 billion in total personal income each year, according to the Maryland State Archives, and brings in almost $400 million in annual tax revenues.

More than 50 ocean carriers use the port every year, making a total of almost 1,800 trips a year.

Alongside its use as a major port for so-called roll on/roll off container shipping, the Port of Baltimore also serves as a cruise terminal.

Last year, more than 440,000 individuals cruised out of the port -- the most since 2012 -- according to the Governor's office.

- 'Inadequate' protection -

Major bridges over shipping lanes like this one are supposed to be designed in such a way to minimize damage in the event of a collision, according to bridge designer Robert Benaim.

"Clearly the protection of the piers in this instance was inadequate," he said.

"A pier or column of a bridge could never resist the impact of a large ship. They must be protected from collision," he added.

"It's evident that the pier couldn't withstand the impact energy, leading to its failure and subsequent collapse of the steel truss and reinforced concrete deck superstructure," said University of Warwick structural engineering professor Toby Mottram.

"The extent of the damage to the bridge superstructure appears disproportionate to the cause, a matter for future investigation," he added.

R.Lin--ThChM