Former 'cutting edge' Morandi Bridge in Genoa was plagued by expensive maintenance issues before motorway collapse

Tom Clarke

Former Science Editor

It's now emerging the Morandi Bridge in Genoa was renowned in structural engineering circles as one plagued by expensive maintenance issues throughout its lifespan.

Urgent repair work took place to cables supporting the roadway in the early 1990s.

In May of this year a tender for more than €20 million (£17 million) went out to carry out similar repairs to cables on the other two towers of the bridge.

When it opened in 1967 the bridge was seen as cutting-edge.

Designed by engineer Ricardo Morandi, it used the latest techniques of "pre-stressed" concrete throughout its design.

Rescuers work in the debris. Credit: AP

The technique relies on steel cables or tendons that run through concrete elements and compress them.

Squeezing concrete in this way gives it better mechanical properties meaning less can be used to make strong bridges.

On the Morandi bridge key load bearing "stay-cables" which hold up the road way were encased in pre-stressed concrete.

It soon emerged that steel tendons could be prone to corrosion and later designs include features that protect the steel and make it easier to inspect for wear and tear.

Rescue teams dispatched to the bridge collapse. Credit: AP

The tender for a repair contract, which went out earlier this year, was to strengthen the cables on all sections of the bridge.

Since the 1970s there have been running repairs to the bridge to solve other problems in the roadway, which is also made of early pre-stressed concrete, which had warped and buckled.

Engineers interviewed by ITV News suggest its sudden catastrophic collapse points at a failure in one of these pre-stressed concrete elements.

Some 20 vehicles plunged into a void after a 200-metre section of the Morandi Bridge. Credit: AP

"It's more likely to be a problem with maintenance than with the structural design of the bridge itself," said David Knight of the Institution of Structural Engineers.

But he added the design of the bridge likely made it very hard to inspect and repairs very expensive to carry out.

The Italian government was quick to blame Autostrada, the infrastructure company responsible for maintaining Italy's roads, for failing to maintain the bridge adequately.

The company said it was working with authorities to establish the cause of the disaster.