Engineers claim there is 'No design flaw' in low-clearance Dublin tunnel

There is no design flaw in the Dublin Port Tunnel, the project's engineers insisted yesterday, even though it will be too low for some of the 9,000 lorries which use the port each day.

The tunnel, the major element of the city council's plan to reduce the number of articulated trucks trundling through Dublin's city centre each day, is designed to fast-track lorries from the M50 to the port. The expected cost is around €448 million (£353 million).

However, members of the Irish Road Haulage Association have said that the tunnel's clearance height of 4.9 metres is too low for some of the more modern rigs.

And despite the clearance height, the actual height of vehicles using the tunnel will be further restricted, to 4.65 metres, as in the case of the Jack Lynch Tunnel under the River Lee in Cork.

The number of lorries affected by the restriction has been variously estimated at "a few" by the National Roads Authority, to at least 1,000 per day by a newspaper report yesterday. Mr Gerry McMahon, a spokesman for the Irish Road Haulage Association, yesterday put the number affected at "400 to 500" per day.

He said some of those most affected would include car transporters whose rigs were considerably larger than most lorries.

Given the significant rise in car sales in the Republic in recent years, there has been a corresponding rise in the number of car transporter movements through Dublin port, he said.

Mr McMahon said his organisation had made the limitations of the tunnel design known in September or October of last year, in conjunction with other users of the port. He said it was regrettable that the tunnel could not have been made larger. The figure of 500 lorries, if correct, would represent about 5.5 per cent of the heavy goods traffic passing through the port each day.

However, along with a projected increase in traffic volumes at Dublin Port over the next three years, the percentage of larger trucks is also expected to rise. It is estimated that traffic through the port will grow from about 20 million tonnes in 1999 - representing a value of about €38.1 billion (£30 billion) - to about 26 million tonnes by 2005.

However, Dublin Corporation and the National Roads Authority maintain there has been no design flaw in the tunnel.

A statement issued last night on behalf of Dublin Corporation's project engineer, Mr Sean Wynne, said he was "satisfied the vast majority" of trucks would be able to use the tunnel which, he pointed out, had a diameter of 12 metres.

A spokeswoman said it had always been known that some of the larger lorries would not use the tunnel, and there was no suggestion of a flaw.

Other sources indicated last night that another proposed tunnel, to be built under the Shannon at Limerick, would have the same height restrictions.

When completed, the Dublin Port Tunnel will consist of twin tunnels running from just south of the Coolock interchange to a new interchange at Dublin Port. Each tunnel will carry two lanes of traffic in one direction.

The project will link Dublin Port to the M50 with a travel time of six minutes, not allowing for toll delays. It will comprise 5.6km of dual carriageway, 4.5km of which will be tunnelled.

Meanwhile, the Minister for the Environment, Mr Dempsey, moved yesterday to allay fears that road projects proposed under the National Development Plan would not be completed within the plan's timescale, by 2006.

He said NRA planners were drawing up their priorities for the current year and there would be no undue delay in schemes which are important for the national infrastructure.