A REPORT to estimate the work involved to increase the clearance height of the Dublin Port Tunnel for bigger trucks is being revised after the project client challenged dimensions used in the draft.
NCEI has learned that calculations in the draft by consultant Atkins for the Irish Department of Transport were based on design drawings rather than asbuilt dimensions.
Joint clients, The National Roads Authority and Dublin City Council, are both opposed to changing the scheme which is under construction. They say work could cost $120M and delay the 2005 opening.
The draft Atkins report is believed to have estimated that work would cost only $34M with just two months delay, a cost believed to be acceptable to transport minister Seamus Brennan (NCE 13 November).
But deviation of the tunnel boring machine during driving - within limits allowed by the contract - is believed to have 'eaten up' tolerances in design drawings which were assumed to be available to increase the height.
Brennan was due to receive the final draft of the Atkins report into the feasibility of changing the clearance height as NCEI went to press. .
The tunnel is designed for the European standard clearance of 4.65m. This is too low for the new generation of super trucks.
Atkins said it could not comment on the report. A revised draft giving a higher cost could sway Brennan against the move.
He is expected to announce his decision within weeks.