Two new bridges being designed for the East End will be able to withstand Bermuda’s challenging climate including hurricane conditions and high humidity, designers said.

The blueprints for the “landmark structures”, replacing the Swing Bridge and Longbird Bridge in St George’s, were presented to the public at an information session at Penno’s Wharf on Wednesday evening.

Steve Thompson, director of major crossings at Ramboll, the lead design consultant on the project, said that the new state-of-the-art Swing Bridge would need to be lowered and locked down during a hurricane, but could remain open for traffic depending on wind speeds.

Construction on the crossings is expected to begin next summer.

It is estimated that the Longbird Bridge onto St David’s Island from the Causeway and The Main (Bermuda’s largest island) will take two years to complete and the Swing Bridge from St David’s to St George’s Island will be 30 months to completion.

Disruption to traffic in both will be “minimal” during the construction phases.

Speaking of the swing section that will lift up every 30 minutes to allow large marine vessels to pass, Mr Thompson told the packed audience: “Wind loading is extremely important.

“We have done initial studies that indicate that the structure is stable during even hurricane winds.

“We don’t have any concerns at the moment but it is something that will be studied in more detail.”

Both bridges will be “built to last” avoiding elements such as sharp edges which can easily rust and incorporating curves designed for free flow of water.

Ricardo Graham-Ward, bridge engineer for the Ministry of Public Works, added: “The new designs also must accommodate for rising storm surge in the future.”

These two “important links to the East End” will include adjoining walkways for pedestrians.

If enough money is left over at the end of the project, the walkway could be extended to run alongside the Causeway, a feature one member of the audience said locals had wanted for years.

The temporary bridges alongside Longbird Bridge will be kept open and the old Swing Bridge will remain operational until the new bridge is fully operational.

The new bridge will take four minutes to raise and two minutes to lower, the same as the current bridge.

Mr Graham-Ward said the Swing Bridge will be operated and maintained locally creating jobs and can function manually when maintenance works are in progress.

He said that both bridges will be wider to improve road safety and will have increased clearance for marine vessels.

One member of the public asked whether the Longbird Bridge could have extra clearance to allow vessels such as fisheries and emergency boats to pass under.

The presenters promised they would look into it.

The two structures are designed to mirror each other and take cues from Bermuda’s natural environment.

The Swing Bridge is inspired by the eagle ray while the design of the Longbird Bridge is inspired by a combination of seashells and sea turtles.

Mr Graham-Ward said: “We want this bridge to be a spectacle, we want this to be an attraction, almost like a destination.

“Because of the proximity to the airport these are the first two main structures tourists will see and the last thing they see when they leave.

“It is important to entice them to come back and think that not only is Bermuda’s environment beautiful, but so are its landmarks. It is a great opportunity to create an identity.”

The potential costs of the bridge were not discussed.

When asked by The Royal Gazette, Minister of Public Works Lieutenant-Colonel David Burch said he had learnt not to give cost estimates too early in a project.

He said: “It will come back to haunt you. We’re not prepared to do that until we have the detailed designs for the bridge and know what materials we are going to use.

“At the end of phase three, we will have a figure of what it will cost.

“That will be driven, like everything that you build, by when you pull the trigger.

“If you wait, the number will only go in one direction.”

Mr Graham-Ward invited school groups get involved in the project.

He said: “I read in the newspaper that the schools are trying to implement a Stem curriculum.

“I am sure that this bridge project can be implemented into that curriculum either by a hands-on approach or by having students come on for site visits during the construction phases.”

The public were encouraged to offer input or voice concerns about the plans by contacting the Ministry of Public Works.