KUALA LUMPUR, July 31 — National public transport operator Syarikat Prasarana Negara Bhd said today that structures used for the LRT Line Extension Project (LEP) pose no threat to its surrounding areas and are firmly secured, despite their “hanging” appearance.

The assurance comes after motorists here expressed concerns over the unfinished structures that appear to be hanging across and over the New Klang Valley Expressway (NKVE), especially near Subang.

“The question of the SBGs works conducted in unsafe manner does not arise at all. All safety processes and procedures are strictly observed and adhered to by our contractors,” Prasarana’s Group Director of Project Development Division, Zulkifli Md Yusoff, said in a statement here.

He was referring to the segmental box girders (SBGs), which are segmented parts of concrete, usually used in constructions of flyovers, bridges, and in this case the elevated railways for the LRT.

To install the SBGs in such a crowded area, Prasarana has used a balance cantilever construction method, which is generally used for or long span crossing over highway, rivers or other wide obstacles over 36m.

“The installation of SBGs with launching girder or gantry has been identified as among the best technique to build bridges and guideway in urban areas where there is working space constraints,” he added, referring to the overhead cranes used to hoist the SBGs.

In a launching gantry mechanism, the SBGs are firmly held by steel cables that are hooked to the launching gantry upon being hoisted. The launcher, in turn, is strongly held by steel brackets wrapped at the guideway piers.

The SBGs are then hoisted and assembled to form the guideway or track of the LEP.

Launching works however, can only be carried out at night in limited time since additional space is needed, causing gaps to be seen by drivers on NKVE during daytime in between installations and assembly.

“On average, nine blocks of SBG could be hoisted and assembled between 11pm and 5am,” Zulkifli explained, stressing that hoisted SBGs are securely fastened to the launching girders before the road is reopened to traffic every dawn.

Zulkifli also stressed that all construction works involving the LEP are monitored and approved by the Department of Occupational Safety and Health (DOSH) and the local authorities to ensure compliance of safety regulations and guidelines. 

The LEP project, originally scheduled to finish by the end of 2014, has recently been hit by a delay of around 18 months with an increased construction cost to over RM8 billion compared to the original RM7 billion.