CLIENT FOR Italy's mammoth Messina crossing, Stretto di Messina, is looking to contractors for a retention payment worth 10%-20% of project cost - or $480M-$960M. It also anticipates the price of the project will be reduced when prequalification bids are submitted on 13 July.
'We are confident the contractor will propose technical innovations as well as savings on materials that will offer significant benefits, ' said chief technical officer Giuseppe Fiammenghi when he visited London last month.
The Stretto di Messina management team stopped off in the UK following whistle stop visits to Tokyo and New York to drum up investor and contractor interest in building what will be the world's largest span suspension bridge, linking the toe of Italy to Sicily. At 3.3km Messina's central span will be a full 1.31km longer than the current record holder, Japan's Akashi Kaikyho.
Some indication of how much improvement on its estimated $4.8bn project cost Stretto di Messina is hoping for is given in its weighting of price in bid evaluation.
Price scores a hefty 45 points out of 100, compared to 15 points for contractual organisation and 15 for the technical and aesthetic content of bids.
Bidders' plans for long term operation and maintenance of the bridge scores 10 points.
Speed of construction, the number of subcontracts to be let and contractors' ability to put up more than a mandatory 10% of construction cost in the form of a retention fee are worth five points apiece.
Fiammenghi said last week that although longer than that of any bridge yet built, construction of Messina's central span posed fairly well tried and tested challenges.
His point was underscored by Ian Firth, partner in UK consultant Flint & Neill, which has been advising on the technical content of the tender documentation.
'I don't think there's anything too unusual going on. The design has been in development for more than 20 years and has been thoroughly tested, ' said Firth.
'Yes it's big, and there could be issues associated with scaling up that haven't been caught. But I would be surprised, ' he said.
Messina's vital statistics make for impressive viewing.
With a total length of 3,666m, its deck will consist of three discrete steel boxes running across transverse girders.
Trains will run on the bridge's central deck box, with three lanes of traffic on the boxes flanking it.
Fiammenghi described the deck as a 'third generation design'. It improves on the aerodynamic performance of single steel box girder decks by allowing cross winds to pass through as well as around it, reducing wind-induced oscillation or 'flutter'. The deck's 60.4m width provides unusual longitudinal stiffness.
Exceptionally tall steel towers are needed to support the suspension cables - they will stand at 382m.
Main suspension cables will be paired to reduce diameter and resulting wind resistance.
Even so each will have a diameter of 1.24m.
Stretto di Messina openly admits that sourcing materials for such a vast project is expected to be problematic.
'We envisage this project will require a combination of several suppliers, ' Fiammenghi said.
The winning bidder will operate as an engineer, procure and construct - or EPC - contractor, dealing with everything from land acquisition through detailed design, construction and construction management.
Stretto di Messina envisages a 78 month construction period starting in January 2006.
For its part, Stretto di Messina insists that after being repeatedly bogged down in the financial mire, the project is now on firm ground with 40% of construction cost to be borne by Stretto di Messina itself. The client is composed of Italy's highways and railway companies, plus the regional governments of Sicily and Calabria.
It calculates that forecast 9% rates of return from bridge tolls over its 30 year operating concession will be enough to hook in private sector finance for the outstanding 60%.