Six years of planning, design and construction culminate this month with the inauguration of 30.5km of new rail line. Andrew Mylius reports.
Few passengers will give a second thought to construction when they step aboard the sleek, air-conditioned trains gliding between stations on the Kowloon-Canton Railway Corporation's (KCRC) new West Rail line. The toil and grime of construction sites, the technical uncertainties and upsets associated with piling and tunnelling, and the brain-racking involved in overcoming them, are far removed from the clean, cool efficiency of the operating railway.
West Rail, which is scheduled to open this month, is a 30.5km long, twin track transport artery extending out from Nam Cheong in West Kowloon to Tuen Mun in the New Territories. Trains travelling at up to 130km/h will hurtle between the line's seven intermediate stations, covering it end-to-end in 30 brief minutes.
Ultimately, West Rail trains will chase each other down the line at intervals of just 105 seconds, carrying close to 100,000 passengers per hour.
Rail afficionados should be impressed by the figures. They tell of finely tuned track, and state of the art signalling and rolling stock.
Trains on the new line are a hybrid between inter-city and mass rapid transit types, says KCRC general manager for railway systems Leo Mak.
'They've been largely designed by KCRC as we require them to fulfil an unusual role, ' he explains. 'The challenge is that on one hand they need to run at 130km/h to minimise journey time between outlying new towns and urban areas of Kowloon, but on the other hand we need mass rapid transit type carriages because of the number of people we need to carry. For passengers it's like riding a high speed metro train.'
During rush hours there will be 335 passengers in each car, 283 of whom will stand. To prevent them being flung about as the train flies along, the track has had to be laid to unusually tight tolerances. Such accurate working tests the mettle of any contractor - but combined with the fact that over a third of the alignment is in tunnel and half is on viaduct, the numerous construction teams involved in delivering the railway really had their work cut out.
Tunnelling was frequently in poor ground with rapid transitions, ranging from competent rock to recently reclaimed land.
To cope with the challenging terrain an earth pressure balance tunnel boring machine (TBM) was used for the first time in Hong Kong. In a region where drill and blast excavation is the industry standard this has been a really pioneering move, says West Rail director Ian Thoms.
Thoms also pays tribute to the epic piling work carried out for all the stations and the viaduct.
There have been environmental, social and meteorological challenges to overcome: West Rail is not just one of the most complex infrastructure projects undertaken in recent years, it is also the first major scheme to come under Hong Kong's new environmental impact assessment ordinance, introduced in 1997 just as design got under way.
One of the principal reasons for running West Rail either under ground or on viaducts has been to avoid conflict with the roads, services and drainage channels, or 'nullahs', at ground level - when it rains much of the alignment can be swept by flash floods. This system minimises land take and associated damage to the corridor's ecology. And tunnel and viaduct have been used to put physical distance between the rail line and residents living close to it.
'In terms of engineering, West Rail is a superlative achievement, ' Thoms enthuses. What makes the achievement all the more remarkable is that, in delivering West Rail for HK$46.4bn (US$6bn), a colossal HK$17.6bn (US$2.27bn) saving on the anticipated construction cost has been achieved.