Zelan Shows Its Mettle In Extreme Engineering

Zelan Shows Its Mettle In Extreme Engineering

22 September 2007

HANGAR 06 at the Kuala Lumpur International Airport in Sepang is an engineering marvel. It holds the record of being the world's longest column-free hangar, spanning 231 metres wide and standing more than 10 storeys tall.

The hangar was built for Malaysia Airlines (MAS) by Zelan Construction Sdn Bhd and had to be big enough to house three airplanes - two Airbus A-380s and a Boeing 737.

Zelan Construction general manager Ang Keng Hong, who was in charge of day-to-day construction of the hangar, recalls that intricacies involved in building a bigger and better hangar for MAS included some extreme engineering solutions.

The hangar had to be tall enough to accommodate the double-decked Airbus 380, but at the same time could not be too tall as to compromise flight path criteria laid down by the Department of Civil Aviation.

The hangar was built for Malaysia Airlines (MAS) by Zelan Construction Sdn Bhd and had to be big enough to house three airplanes - two Airbus A-380s and a Boeing 737.Zelan Construction general manager Ang Keng Hong, who was in charge of day-to-day construction of the hangar, recalls that intricacies involved in building a bigger and better hangar for MAS included some extreme engineering solutions.The hangar had to be tall enough to accommodate the double-decked Airbus 380, but at the same time could not be too tall as to compromise flight path criteria laid down by the Department of Civil Aviation.

MAS also wanted the new hangar to be equipped with automated teleplatforms, a landing gear system, ground service pits and sensor-triggered fire-fighting facilities. Above all, to save on maintenance cost, the structure had to be energy-efficient too.

Teleplatforms are big mechanical hands attached to crawler-hoists on the roof that move maintenance crew around the planes.

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Zelan Construction managing director Lam Kar Keong spoke on challenges and engineering solutions incorporated into the project.

"This hangar is the first of its kind in the world. We had to start from scratch ... we were venturing into uncharted territory. Since teleplatforms are usually fixed to the roof, we use pre-tension high-grade steel for maximum strength and yet, is relatively lighter than ordinary steel," Lam said.

The next challenge was to put up the structure as fast as possible.

"It was an extremely short completion period, at least five months shorter that a similar project of this magnitude and complexity. To fast-track the whole construction process, we incorporated the Parallel Truss system,"he said.

Instead of the conventional way of building the walls of a structure first and then the roof, the builders started with the roof. Engineers assembled the roof and installed the lighting, fire-fighting and crawler-hoisting facilities while on ground. Subsequently, the "completed roof" was jacked upwards from the ground - bit by bit over 10 days.

Weighing about 5,500 tonnes, the roof was pushed up at snail pace using 22 hydraulic jacks wired to a central system to synchronise the lift. Lam likened it to raising a platform as big as three football fields with about 2,800 elephants strapped to it.

"To ensure absolute stability, we measured every stress point as the roof went up milimetre by milimetre. Throughout the 10 days, it was a painstakingly tedious and a very delicate procedure," he said.

If the roof had been lifted unevenly, it would have cracked and fallen apart, thereby incurring substantial losses and possibly injuring workers along the way.

Asked if he had any doubts or regret throughout the project, Lam replied, "Everyone was very nervous before the lift. It was never done before at such a scale and many had 'what if' type of questions circling in their heads."

Looking back, he believes the project was a major milestone for Zelan.

"We really built to the limit. No where in the world had anyone lifted roofing of such wide span at one go," he said.

At the event, Construction Industry Development Board chairman Tan Sri Jamilus Hussein said the successful implementation of small, medium or complex projects can be traced back to the ability of project managers.

He said it is essential for project managers to be capable of handling high expectations from their stakeholders, international relationship, global politics and environment issues.