CIE intends to operate the planned Luas light rail system "on a 24-hour basis, 365 days a year, if passenger demands so require", the public inquiry into the Sandyford-St Stephen's Green line has been told.
Mr Michael Sheedy, the Luas project manager, said this most likely would be achieved by running a late-night service similar to the Nitelink operated by Dublin Bus. CIE believed it was essential to build the first phases of the project to a high standard.
This approach would be more likely to promote the implementation of subsequent phases, he said. "A cheap and cheerful scheme would be seen as negative and take from the perception of a quality system which is essential to its high patronage."
Mr Sheedy revealed that CIE had decided in principle that the entire Luas fleet would be upgraded to a "fire rating" class compatible with extended underground running, to comply with the Government's decision last May to go underground in the city centre.
Giving evidence on the second full day of the inquiry before Judge Sean O'Leary, he said the proposed depot for Line B would be at Sandyford, with sufficient "stabling space" to cater for 24 Sandyford trams, each 30 metres or perhaps 40 metres long.
Maintenance on the trams would be carried out on a 24-hour basis, but indoors to minimise any over-spill of noise to the adjoining Woodford housing estate. The depot would also be screened for noise and light abatement to protect residential amenities.
Mr Sheedy said an application to extend the Tallaght line from Middle Abbey Street to Connolly Station and Docklands is expected to be lodged by this summer. Work on Line B would start in the first half of next year at the latest and would take about three years.
Construction time in any sector of the city would be about 18 months and would not exceed six months in any one street. The first phase of the project, involving the diversion of gas, water, electricity and telecommunications would be the most difficult.
However, the project manager said it was neither practical nor cost-effective to divert very large-diameter sewers. These would be "virtually impossible to relocate" and therefore must remain in situ. They would be relined internally to prolong their useful life.
Mr Eamonn Brady, the Luas information officer, said disruption during the construction phase was one of the main concerns to emerge from an extensive public consultation programme. Others related to traffic management and access to residential and business premises.
People were also concerned about intrusion and security, maintenance of existing residential parking facilities, noise and vibration, integration with other public transport services, park-and-ride capacity, boundary treatment and access to LRT stops, he told the inquiry.
Mr Dick Gleeson, deputy planning officer with Dublin Corporation, said it strongly supported the Line B plan and was committed to dealing with any problems associated with its implementation.
Mr Gleeson said the planners were satisfied that CIE's design approach to Luas constituted a sensitive response to the challenge of integrating LRT into the historical fabric of areas such as St Stephen's Green, Harcourt Street and the Grand Canal crossing.
However, he said the City Canals Group, a task force made up of Duchas and the corporation, believed it would be wasteful to carry out improvements to the canal east of Charlemont Street bridge that would be destroyed or severed by the Luas construction.
Mr Bernard McHugh, planning consultant for the project, pointed out that only 12 per cent of the total length of Line B would be on-street, with the rest laid on the former Harcourt Street railway line. However, temporary compounds would be required at a number of locations.
He said the provision of park-and-ride sites at Balally and Sandyford Industrial Estate were designed to attract a significant number of motorists. In the case of Balally, however, this would require the removal of more than 30 mature trees.