The Tiger Sky Tower on Sentosa reopens today, more than three months after it was closed due to an incident that stranded 39 people in midair for four hours.
The Building and Construction Authority (BCA) told The Straits Times yesterday that it had given written permission for the Sky Tower to resume operations on Tuesday after it inspected the repairs and rectification measures.
It added that a report from the specialist professional engineer appointed by the ride operator, Sky Tower Pte Ltd, stated that the breakdown was caused by a drive unit that overheated, and noted that the rescue was hampered by the failure of the manual winch used to bring the gondola to the ground when the drive unit malfunctions.
"A procedural lapse in the manual winching process... resulted in a failure of the manual winch," said the BCA.
The Straits Times understands that the gondola was ultimately lowered using the overheating drive unit.
The authority has reviewed the report and concurred with the engineer's conclusions.
Sky Tower said it undertook "extensive investigations" with the BCA and German ride manufacturer Huss Park Attractions.
A spokesman for Sky Tower said the faulty drive unit - the component responsible for raising and lowering the gondola - has since been replaced. As a precaution, unaffected areas of the ride were also inspected.
Sky Tower also said it had conducted a comprehensive review of its emergency response plan, boosted its "technical manpower" and conducted further refresher training for its staff in a bid to enhance its operational capabilities.
The ride, launched in 2004, reaches a height of 110m. It can ferry up to 72 passengers to the top via an enclosed, air-conditioned cabin, also known as a gondola. The seven-minute ride affords views of Sentosa, Singapore, and parts of Indonesia and Malaysia.
On Aug 12, the ascending gondola stopped moving at the 25m mark, trapping the 39 passengers - including children and the elderly.
Sky Tower director Alexander Melchers told The Straits Times that the gondola, which was equipped with fail-safes similar to those found in lifts, was never at risk of plunging to the ground.
He added that the company had ensured that the trapped passengers, mostly tourists, were able to proceed with their itineraries or were compensated via flights or accommodation if their travel plans were disrupted.
In 2010, the tower stalled in midair in two separate incidents, and it took around two hours for the issue to be resolved in each of the previous incidents.
Said the spokesman: "We take this opportunity to assure all our guests that safety is of paramount importance to us, and rigorous tests have been conducted to ensure that the Sky Tower remains safe for all visitors to enjoy.
"The Tiger Sky Tower team again apologises for the inconvenience caused by the incident, and we look forward to welcoming our guests once again."