THE five pre cast concrete units which will form part of the £90 million Lee tunnel in Cork will he floated out to the Lee estuary next week.
The tunnel - the biggest single infrastructural project undertaken by any local authority in the Republic - will be a two by two lane dual carriageway with north bound and south bound traffic running in separate bores.
There will also be a central service passageway to allow for emergency evacuation and, if necessary, the arrival of emergency services.
The scheme is being financed by the National Roads Authority and is being grant aided by the EU Cohesion Fund at 85 per cent of the total outlay.
The tunnel itself will cost £67 million. The remainder of the £90 million is being spent on approach, roads and infrastructure. It is estimated that when the project is completed in May 1998, the annual running costs will be about £500,000. The likelihood is that a toll will be charged to offset these costs.
It is expected that more than 20,000 cars a day will use the tunnel initially, and that this will double within 20 years.
The tunnel is one of the key elements of the Cork Land Use and Transportation Study developed in the 1970s, and is designed to divert traffic from the centre of the city.
From next year, cars approaching Cork on the main road from Dublin will be able to avoid the heavily congested city centre, and Dublin bound traffic from the west will be able to do likewise.
Cork Corporation is hopeful that once the scheme is completed, the city centre will be landscaped in a manner more friendly to pedestrians and the environment.
All the tunnel services will be controlled from a building on the northern side of the Lee, Closed circuit television monitors will he connected directly to the Garda and Fire Brigade headquarters in Cork city.
The contractors - a joint venture team including the Irish firm P.J. Walls and an English company, Tarmac Construction Ltd - anticipate that within the next month the five pre cast tubes will be submerged beneath the Lee. Shipping movements will be restricted for up to 48 hours. But once the tunnel is in place ships will be able to approach the Cork quays as usual. The tunnel units will have a length of 122 metres with an external width of 24.5 metres. The dry weight of the five units is 27,000 tonnes.