Irregularities at Hong Kong’s costliest rail link were worse than a high-level investigation had previously indicated, according to government-appointed experts who branded the problems “unacceptable” and “unusual”.
In a 428-page final report released this week, the expert adviser team comprised of three former officials estimated the Hung Hom station of the HK$90.7 billion (US$11.7 billion) Sha Tin-Central link had 700 shortened, defective steel reinforcement bars, or 3.3 per cent of the total on site, and that 1,900, or 8.9 per cent, of couplers were unconnected.
“It should be visually obvious on site that these unconnected ‘coupler connections’ are unacceptable. In a properly managed and supervised site, it is very unusual that such a significant number of unconnected couplers could go unnoticed and unrectified,” it said.
Get the latest insights and analysis from our Global Impact newsletter on the big stories originating in China.
The team was tasked with probing a series of allegations of shoddy work and missing safety documents at the site exposed in May 2018, and providing expert advice on the link’s construction.
One key allegation under examination was that reinforcement bars, or rebar, had been cut short to fake proper installation into couplers on the station platform.
Despite the problems, the expert team said the station was safe after remedial works by rail operator the MTR Corporation.
“With its close involvement and knowledge of the case, the expert adviser team is convinced that with the implementation of the required remedial works, it is safe in practical terms to use the built structures for their intended purposes,” it said.
However, the team’s findings showed a discrepancy with those of the government-appointed commission of inquiry headed by former judge Michael Hartmann in May last year.
The commission also said the site would be safe for use and “fit for purpose” with some remedial works. While confirming staff of subcontractor Fang Sheung Construction had cut the rebar, the commission dismissed the problem as “not extensive” and amounted to 2-3 per cent of the amount used.
But the expert team said the “alarming” use of 4,000 tonnes, or 7 per cent, of untested rebar might compromise quality. “It also reflects a serious flaw in site supervision and control,” it said.
The team queried why the “multitude of irregularities” could go unnoticed or unrectified during construction, questioning the site supervision of the MTR Corp and main contractor Leighton Contractors (Asia).
“Many of them have been attributed to causes such as poor workmanship, site difficulties and miscommunication,” it said.
“However, one might wonder why so many construction irregularities could have occurred, and apparently remained unnoticed or unrectified during the construction.”
The team urged the relevant key parties, especially the MTR Corp and the Highways Department, to conduct a candid review of the underlying causes of the irregularities. “The senior management of the respective parties should give its firm commitment and attention to the review and implementation of the required follow-up actions. This is vital to the success of the exercise,” it said.
In response to the report, the government said it was progressively implementing its recommendations.
The team also found the spare capacity of certain parts of the connection between the Tuen Ma Line slab and a diaphragm wall was excessively overprovided by up to 467 per cent.
Another problem was that the spare capacity was unevenly distributed, which the team concluded was likely an inadvertent “overprovision”, rather than a deliberate “conservative design”.
While the team said the spare capacity was so high it was “irrelevant to any conservatism” in the project’s code requirements, it could not even find any justifiable reasons from the MTR Corp’s management.
It urged the corporation to review and improve its prevailing design practice and checking provisions to avoid overly conservative designs.
Registered structural and geotechnical engineer Ngai Hok-yan said the significant spare capacity meant higher costs.
“If the spare capacity is 40 per cent, it is within industry standards,” he said. “The MTR Corp, Leighton and Highways Department should explain why it is overbuilt by so much because taxpayers foot the bill at the end of the day.”
The 17km rail link is due to open in stages, with the final leg – the harbour-crossing section between Hung Hom and Admiralty – scheduled for operation in the first quarter of 2022. But it faces fresh delays after a recent blunder on its signalling system.