Venice holds its breath as the bridge to the future makes its first appearance

The boldest public works project to be tackled in Venice for many decades came a big step closer to completion last night when the two great side buttresses of Santiago Calatrava's new bridge for the city were hauled up the Grand Canal.

While the city slept, a huge, purpose-built barge carried the two prefabricated sections of the city's new bridge up the Grand Canal, which was closed to all other traffic throughout the night. Each of the two sections is 15 metres long and weighs 100 tons.

The most delicate moment came when the barge arrived at the Grand Canal's oldest and most famous bridge, the Rialto, which dates from the 16th century. At this point the keel of the barge was within 10 centimetres of the bottom of the canal, while the steel members, like the skeletons of two enormous fish, passed under the celebrated covered bridge with only 82 centimetres to spare. This part of the journey alone took four hours.

Today and tomorrow the onboard crane will lower the buttresses into place at the top end of the canal, near the railway station, the messy bit of Venice - all car parks, bus stops and railway lines - where the real world and the floating world meet.

The spectacular finale is due to take place in two weeks' time, on the night of 11 and 12 August, when the 60-metre long central span will be brought up the canal, swung round 90 degrees, hydraulically jacked up to the required height then gently lowered into place between the two buttresses.

If all goes well in the next fortnight it will give a happy ending to a tumultuous saga. The genesis of Calatrava's Venice bridge, the first to be built in the city for more than 70 years, has been beset by controversies, from disabled access to the impact of the bridge's great weight on the canal's banks. Costs have soared from €4m (£2.7m) to more than €10m.

Mara Rumiz, Venice's councillor in charge of public works, said she saw the completion of the bridge as "a precise signal for Venice, not to look merely at its glorious past but to engage with the present, in fact to present itself as a model modern city, projecting into the future".

Her vision is on the face of it bizarre: the reason millions flock to Venice every year is to escape everything modern and to immerse themselves in a place that has somehow succeeded in eluding the horrors of the modern age. Yet from a broader point of view the councillor has a point: the city is completely artificial.

And the bold stride into the future represented by the Calatrava bridge is to be repeated. An 830-metre long monorail is due to open in 2009, bringing visitors from the island of Tronchetto, at the entrance of the city, to Piazzale Roma and the Calatrava Bridge.

The city is also studying the possibility of building a metro under the lagoon to serve Tessera on the mainland 13km away, the site of the city's main airport.