Colombo welcomes AHASA ONE – South Asia’s iconic new Sky Bridge

Dominating the city’s ‘Millionaire’s Mile’ on the Galle Face oceanfront, Sapphire Residences – and adjacent five-star hotel ITC Colombo One – is a new landmark that promises to attract the who’s who of local and international investors and guests.

A flagship development for Sri Lanka on the international stage, it is set to redefine luxury living in the Indian Ocean region – not only in terms of world-class amenities and magnificent living spaces but also by delivering an exceptional lifestyle for residents, described as ‘The Splendour of Gracious Living.’

Undoubtedly the most distinctive aspect of this architectural marvel is the spectacular Sky Bridge that joins the two towers c. 100 metres in the air. The first of its kind in South Asia, the AHASA ONE Sky Bridge will feature breathtaking dual panoramic views with two 50 metre infinity sky pools on top, and a jazz bar and lounge below, which are guaranteed to become popular destinations for Colombo’s elite.

A remarkable feat of design and engineering, the details behind the project’s realisation are being broadcast in a new documentary entitled The Making of the Iconic AHASA ONE Sky Bridge.

The film traces the project’s journey from inception to its triumphant execution, revealing the complex engineering challenges. It divulges how the Sky Bridge was conceived, designed and constructed in India, and shipped to Colombo where it was assembled on the ground over several months, before being hoisted and affixed between the towers’ 19th and 21st floors.

The journey in the documentary highlights the numerous challenges faced by the Sky Bridge’s creators as they set about transforming their ambitious vision from blueprint to reality. This structure is the result of a two-year collaborative effort between the design, procurement, fabrication and installation teams.

Weighing a staggering c. 3,000 tonnes when complete – which is equivalent to hoisting more than 160 city buses and securing them c. 100 metres in the air – it’s no surprise that this c. 55 metre elevated pathway challenged the world’s best architectural and engineering minds.

To accomplish this, project developer WelcomHotels Lanka sought the expertise of industry leading names in global design and construction. The list of firms selected reads like a gathering of the world’s leading names in construction and architecture.

They include Gensler (San Francisco), Thornton Tomasetti (New York), Larsen & Toubro (L&T – India and Sri Lanka) and Sterling (India), as well as celebrated Sri Lankan architect Deshamanya Dr. Surath Wickramasinghe, who has been at the forefront of this project since its inception.

This state-of-the-art construction was designed with meticulous engineering expertise and an ingenious system was developed to enable the Sky Bridge to be assembled at the ground level before the massive completed structure was raised into place, ensuring absolute precision during installation.

Indeed, this bespoke technique involved the use of highly specialised and synchronised lifting systems and fabrication methods, together with a unique top-down assembly process in the suspended condition.

It was essential to keep the Sky Bridge level to within about three millimetres throughout the lifting operation. With four lifting points and two strand jacks at each point used in combination to hoist a total of c. 160 high-tension and flexible cables (known as ‘strands’), the entire lifting system delivered a total capacity of almost 2,500 metric tons.

All four strand jacks were synchronised and aligned using a master computer, closely monitored by a highly experienced engineer who controlled the vertical accuracy of each lifting point.

To prevent the Sky Bridge from acting as a rigid structural brace between the two towers (which would impart tremendous forces on the structure), the bridge has to slide – or ‘float’ – on its resting points on each of the towers for which sliding bearings are used.

These bearings prevent any movement other than the designated sliding direction while locking arrangements prevent the risk of excess sliding. The movement of the bearings is caused by the lateral sway of the two towers under wind, earthquake and temperature change conditions.

The installation of the AHASA ONE Sky Bridge was a highly anticipated event with the entire team and spectators assembled waiting with bated breath as final adjustments were made and scrutinised to ensure that it was ready for its final ascent.

On 15 December 2019, the bridge’s ascent began, carefully supervised after scrupulous planning and engineering expertise – the culmination of more than two years’ hard work. Following a lifting process that lasted more than eight hours, the team had every reason to be jubilant as the AHASA One Sky Bridge reached its ultimate resting place c. 100 metres above sea level.

AHASA ONE is not only a stunning piece of engineering designed with incredible style, it is a beacon of Sri Lanka’s resurgence as a country.

This unique Sky Bridge – which connects the iconic Sapphire Residences and ITC Colombo One hotel towers – will be a distinctive landmark for the city of Colombo, putting its skyline on the map alongside some of the most glamorous cities in the world.

– Compiled by Ashwini Vethakan