Survey will test three metro routes to airport

A geotechnical survey of route options for the Dublin Airport Metro will test underground conditions along three options, the Department of Transport announced yesterday

But the survey will not affect the Government's decision that the preferred route has already been selected, the department added.

While the testing of three routes would now appear to be a fruitless exercise, given that the Government has already selected one of them, the Railway Procurement Agency (RPA) defended the system yesterday

An RPA spokesman said it was an EU requirement that all options be tested. He later added that testing of all three options would be required for the environmental impact statement and the public inquiry, regardless of the "preferred route".

In the Government's recently announced Transport 21 policy, a route from St Stephen's Green via the Rotunda and Mater hospitals, Botanic Gardens and Ballymun Road to the airport was chosen. The two other route options were Broadstone/Cabra/Finglas Road; and Drumcondra/Swords Road.

Test drilling of hundreds of small holes along the potential routes is to begin in April and will be completed by the end of the year. The holes will be up to eight inches in diameter and will be sunk to a depth of up to 54 metres.

The department said the survey was "needed to help to decide on the preferred route alignment and station locations, and thereafter the detailed design of stations, tunnels, elevated structures and surface track work".

The information that the geotechnical survey would examine the rejected routes came as a surprise to the Labour Party transport spokeswoman, RóisíShortall, through whose Dáil constituency the line runs.

Ms Shortall said she understood one route had already been selected - the Ballymun route. She said she had an appointment with the RPA tomorrow to discuss the route. "I am going to meet them to discuss things like whether it is overground or underground at specific locations," she added.

A spokesman for the Minister for Transport, Martin Cullen, said the Government decision on the airport metro route would not be changed. He indicated that some of the test holes along the two rejected routes could be used for the construction of Luas and/or the Metro west.

Contracts for the survey work are expected to be signed in March. The boreholes will be drilled in the ground at a number of locations including the city centre, in the vicinity of Harcourt Street, St Stephen's Green, Dawson Street, Nassau Street, D'Olier Street, O'Connell Street and Parnell Square. There will also be several boreholes located within the airport complex.