Half of the 65 per cent rise in the cost of the planned high-speed rail line to Guangzhou is due to the many design improvements, and the other half is because of unexpectedly high inflation, transport officials told lawmakers yesterday.
At a special meeting to explain to legislators the detailed cost breakdown, Secretary for Transport Eva Cheng said new railway construction standards on the mainland, revised last year, and the enhanced design of the terminus in West Kowloon, were among factors that raised the cost from HK$39.5 billion, estimated in April last year, to HK$65.2 billion.
The diameter of the 26-kilometre railway tunnel, for example, had to be widened from 7.8 metres to 8.15 metres to meet the new mainland standard, which lowers the impact of air pressure on passengers' ears.
The design of the tunnel section in Futian, Shenzhen, also changed from a single tube to double tubes to take into account the sensitive underground water situation at the Mai Po wetland on the Hong Kong side. Director of highways Wai Chi-sing said: 'It will be fair for Hong Kong to shoulder the costs.'
Other design changes include strengthening of buildings' foundations, drainage pipes and other tunnels that the railway will run close to, and increasing the number of tracks from three to eight at the Pat Heung emergency rescue station.
Wai said the underground situation in urban areas was found to be more complicated as further surveying work continued.