ROME -- Rival engineers are competing to build a suspension bridge or a floating tunnel between Sicily and the Italian mainland, an idea first conjured by the warrior Hannibal more than 2,000 years ago.
The notion of spanning the choppy waters of the Strait of Messina goes back to around 218 B.C., when the Carthaginian general invaded Italy. Hannibal reputedly wanted to move his elephants across the strait on a pontoon bridge.
But technical difficulties in an area prone to earthquakes, gusting winds and strong currents prevented any serious contemplation of the task until about 20 years ago.
Two days after Christmas, Prime Minister Bettino Craxi formally commissioned a state-owned company, Strait of Messina, to study, build and operate a road and rail link by 1997.
The company quickly produced a report plumping for a single-span suspension bridge -- the world's longest, more than doubling the length of the present record holder, the nearly one-mile Humber span in Britain.
Designers say a single, open span is called for to keep from choking ship traffic in the already-crowded strait.
The 2-mile span would go from Villa San Giovanni, near Reggio di Calabria, on the mainland to just north of Messina at a narrow point on the strait. Its towers would be 1,312 feet high, half again as tall as the Eiffel Tower in Paris or about the same height as New York's Empire State building.
Its cost: an estimated $3 billion.
A cheaper but more experimental alternative is a submerged, floating tunnel.
For the moment, ferries carry 2.5 million automobiles, 650,000 railroad carriages and 1 million trucks a year across the strait. The passage takes only about 15 minutes, but with loading and unloading it can take up to 3 hours.
Many Sicilians and Calabrians are skeptical whether anything actually will be built, dismissing the current debate as a sign that elections are imminent.
Politicians in Italy's depressed 'Mezziogiorno,' or deep south, are wary of grandiose projects. They recall a big port project at Gioia Tauro in Calabria that cost hundreds of millions of dollars but was never opened.
But those working on the plans are enthusiastic. Gianfranco Gilardini, an engineer who is Strait of Messina's managing director, says the spectacular span could resist winds gusting up to 60 mph, tidal currents up to 6 knots and earthquakes as strong as those that destroyed Messina and Reggio Calabria in 1908, killing 60,000 people.
'All this is possible because of the highly advanced nature of our studies,' he says.
Alan Grant, a British engineer, designed the main alternative to the bridge -- an enclosed concrete tunnel submerged 197 feet under the water and fixed to the seabed by cables, floating because of its own displacement of water. It would cost only half as much as the bridge.
Gilardini points out the tunnel idea is untested. But, says Grant, so is such a long suspension bridge. He says rail traffic would strain it severely.
He contends each component of his floating tunnel has proved its worth elsewhere, especially when used by oil companies in the North Sea.
Gilardini says wind tunnel tests by the railway subsidiary of the Fiat automobile company prove trains can cross the bridge safely. Fiat and other industrial interests are known to favor the bridge.
It also seems to appeal to Italian politicians as a more spectacular monument to Italian engineering.
Whichever idea is adopted, Italians need not hold their breath.
Once a decision is taken -- probably some time this year -- two years of detailed design and preparation would follow. An act of parliament would be needed to get the project under way.
Construction could start in 1989, and could take until 1997 to finish.