AUTHORITIES say there are measures in place to protect the Forth bridges from the kind of disaster that happened in the USA this week.

The Francis Scott Key Bridge in Baltimore collapsed into the Patapsco River on Tuesday after a container ship smashed into a pillar on the 1.6 mile crossing, with at least six people presumed dead.

The crew had issued a mayday to say they'd lost all engine power and the vessel was adrift, giving authorities time to stop road traffic and undoubtedly preventing further loss of life.

A spokesperson from Forth Ports said: “As a part of the ports and shipping community, we were shocked by the tragic events in Baltimore this week.

Dunfermline Press: The Francis Scott Key Bridge spanned the Patapsco River and is next to the Port of Baltimore. The Francis Scott Key Bridge spanned the Patapsco River and is next to the Port of Baltimore. (Image: Harford County MD Volunteer Fife & EMS / PA)

"Forth Ports is the statutory harbour authority for the Forth and Tay estuaries and we have a strict set of safety procedures and marine guidelines to ensure the safe navigation for all vessels transiting under the bridges.

“We have well established navigation channels for all bridges and most ships will have an authorised marine pilot on board who are extremely experienced in navigation of these waterways.”

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Eight workers were fixing potholes on the bridge when it was struck by the Dali, a cargo vessel from Singapore, and several vehicles also fell into the water.

Two men were rescued from the river, two bodies were later found and the remaining four are presumed dead.

Dunfermline Press: The bridge before the disaster. At 1.6 miles, it was just longer than the Forth Bridge. The bridge before the disaster. At 1.6 miles, it was just longer than the Forth Bridge. (Image: Alamy / AP)

While cargo vessels like the 300-metre long Dali - which was said to be carrying at least 3,000 containers - would be a rarity in our waters the Scottish Government did have plans for an £85 million international container terminal at Rosyth.

And last week we had the largest warship ever built, the HMS Queen Elizabeth weighs 65,000 tonnes and is just a little shorter, at 284m, sailing under the Forth bridges.

Dunfermline Press: The HMS Queen Elizabeth sailing under the Forth bridges on her way to Rosyth for repairs.The HMS Queen Elizabeth sailing under the Forth bridges on her way to Rosyth for repairs. (Image: David Wardle)

A Transport Scotland spokesperson said: “Protection from potential ship impacts was carefully considered during the design of the Queensferry Crossing.

“The main shipping channel is between the south and centre towers, so the south tower and the nearest south approach viaduct pier had additional strengthening incorporated during the construction process.

"The centre tower is founded on Beamer Rock and this acts as a natural protection.

“The Forth Road Bridge has fender protection fitted.”

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The road bridge, which opened in 1964, had new defences installed around 30 years ago after a report identified that its two steel towers could be at risk in the event of a collision involving a tanker or other ships.

Dunfermline Press: The collision protection measures being installed on the Forth Road Bridge in 1997. The collision protection measures being installed on the Forth Road Bridge in 1997. (Image: Paul McIlroy)

The contract for the £5 million project was put out to tender in April 1996.

The eight-month project saw new defences constructed around the submerged piers forming the bases of the towers.

The aim was to avoid the "nightmare" scenario of a wayward vessel crashing into the bridge and causing severe structural damage.

It was envisaged that crash barriers "resembling a chain of giant soup tins filled with rubble" - also known as cellular cofferdams - would be built alongside each tower.

A spokesperson for Network Rail, who look after the Forth Bridge, said: "The structural design of the Forth Bridge allows greater redistribution of loading in the event of damage. 

"Each cantilever is supported on four robust caissons filled with concrete and granite, which are further protected by natural rock features both above and below the waterline. 

"The largest ships which pass under the bridge do so under rigorously controlled conditions, with multiple tugs in attendance. 

"To aid shipping movements we have navigation lights installed across the bridge, operated and maintained by Network Rail, indicating the shipping channels and the routes which vessels should take underneath.  

"The port authority also notifies Network Rail in advance of large vessels which are due to transit the bridge, to allow for the cessation of any maintenance activities that could impact on the shipping lane."

The last serious shipping incident in the Forth was on a foggy night in August 1976 when the Royal Navy's HMS Reward sank after being struck by a German container ship.