Tunnel a testament to persistence

To the workers and staff who were involved in the construction of the 12.9km-long Hsuehshan Tunnel, June 16, 2006 -- the day the tunnel opened -- is probably a day they will never forget.

On that day, they proved to themselves, the nation and the world that, after 15 years of work -- and a series of disasters that at one point almost halted the project -- they had accomplished an impossible mission. It was also a day that marked the official opening of the Chiang Wei-shui Freeway, which facilitates travel between Taipei and Ilan counties.

While media coverage over the past few days has focused on the eagerness of motorists nationwide to be among the first through the tunnel, those involved in building it reminded the public how the project began, and most importantly, the hardships workers experienced in completing the challenging task.

The project, which lasted through seven premiers and 10 transportation ministers, began with a vision.

During the 15 years it took to drill 12.9km through a mountain, the ground collapsed 98 times, underground water inundated the tunnel 36 times, tunnel boring machines were trapped inside 26 times and 25 workers lost their lives.

In the late 1980s, the Ministry of Transportation and Communications had already planned the Nangang-Pinglin section of the Taipei-Ilan Expressway, and officials proposed several options to connect Pinglin in Taipei County and the Ilan County.

Ou Chin-der (歐晉德), chairman of the Taipei Smart Card Corp and former director-general of the Taiwan Area National Expressway Engineering Bureau, believed that Taiwan should establish an around-the-island expressway network. His vision was to drill through Hsuehshan to Toucheng (頭城), Ilan County, which would also connect to the highway that leads to Suao (蘇澳).

Boring machines

Construction began in 1991, and tunnel-boring machines were purchased -- under the advisement of overseas experts -- to start drilling through the mountain.

But this decision led to a series of disasters.

The main reason, engineers recalled, was the failure to detect a massive aquitard -- a pocket of water captured in impermeable rock -- that had formed inside a sandstone layer millions of years ago.

When the machines hit the layer, water burst out and flooded the tunnel.

Winson Chang (張文城) is one of the few engineers who managed to remain with the project from start to completion.

Now in his early forties, Chang said the real frustration began when one of the boring machines got stuck in the pilot tunnel in 1993.

According to Chang, construction difficulties continued over the following four years.

The most unforgettable disaster was a ground collapse in 1997, which damaged approximately 100m of tunnel that was already built and caused landslides that moved 10,000m3 of rubble, and buried a boring machine. The manufacturer estimated that fixing the machine would cost twice as much as buying a new one and that repairing it would take an additional 38 months.

After that, RSEA Engineering Corp, the contractor recruited for the construction, decided to forfeit the tunnel boring machines and adopt a drilling and blasting method instead. The risks involved in doing so drove away many potential overseas contractors, who all failed to find insurance companies willing to cover the occupational hazards.