Into the eye of the vortex

Visitors to Jewel Changi Airport in the past week were not able to record an Instagrammable moment.

There was no breathtaking rush of water cascading from the roof of the complex, with the area surrounding the HSBC Rain Vortex cordoned off.

The 40m-tall indoor waterfall, which is the largest in the world, was shut off between last Tuesday and Saturday morning for annual maintenance.

For five days, a team of about a dozen cleaners worked tirelessly to get the job done.

To kick off the process, workers had to thoroughly clean the slabs from a reflective pool surrounding the waterfall on Level 1 of Jewel.

The surfaces of these slabs are cleaned regularly throughout the year, with coins and dirt removed.

But with the annual cleaning, workers had to remove more than 100 slabs - each weighing about 20kg - in order to clear the dirt that has accumulated under the pool in the past year. The slabs are moved using suction cups, and cleaning is done using high-pressure jets.

The workers also had to dislodge coins thrown by visitors which might have been stuck underneath the slabs.

Mr Kelvin Tan, head of user experience at Jewel Changi Airport Development, said the presence of the coins may affect water flow and result in more maintenance work. "We hope members of the public can enjoy the HSBC Rain Vortex as it is and refrain from throwing (in) any foreign objects," he added.

The coins are collected and donated to charity.

Workers also had to empty the five water tanks connected to the indoor waterfall. These tanks, in Basement 3 and 4 of Jewel, hold about 500,000 litres of water. It takes about six hours to drain them with vacuum pumps before any stains on the walls and floors can be removed.

The floor of the indoor waterfall gets a check, to extract coins and other objects that might have made their way there.

After the interior of the HSBC Rain Vortex is given a clean bill of health, the exterior of the transparent acrylic column which stretches across Basement 1 and 2 of Jewel is spruced up.

Then, restarting the indoor waterfall gets into full swing. It takes about six hours to fill up the tanks. Chemicals that stunt the growth of algae are dispensed into the water.

The pH level of the water flowing through the waterfall is kept at a specific level to ensure that it does not corrode the tank.

Mr Tan said: "The annual cleaning and maintenance exercise of Jewel's HSBC Rain Vortex is done not only to ensure that the surfaces are cleaned, but that all systems are in check.

"The world's tallest indoor waterfall is a sight to behold and behind it is a complex piece of engineering, which requires every part to be in sync for it to work its magic."

While the HSBC Rain Vortex has resumed operations on Saturday afternoon, its daily light show remains suspended due to the Covid-19 situation.

Jewel opened its doors to the public in April 2019. It is designed by architect Moshe Safdie, who is behind the iconic Marina Bay Sands integrated resort.