ORIGINAL DESIGNS for the 5km gas pipeline which tore free from the underside of Bangladesh's Jamuna bridge are expected to be cleared of blame in the official report on the incident, which is due to be published later this week.
Meanwhile replacement of the 750mm diameter gas main is nearing completion as the row over who was responsible for the collapse rumbles on.
Most of the parties involved are unwilling to comment on the incident until after the report becomes public, but senior principal Mirek Olmer at main contractor Hyundai's structural engineer TY Lin this week denied that there were any problems with the original design of the gas main's hangers.
'Since the collapse we have had additional independent checks carried out on our designs and these confirmed that they conformed fully with the specification, and allowed for the weight of water used during testing,' he said.
The near 5km of main plunged into the river during hydraulic pressure testing less than two weeks before the £154M crossing's official opening (NCE 2 July 1998). It was installed by main bridge contractor Hyundai under the supervision of High Point Rendel.
Local press reports claimed that the cause was a failure to allow for the weight of water in the pipe during testing, but TY Lin strongly denied this at the time.
The pipeline was fixed to the concrete deck via a system of hangers connected to anchors cast into the precast concrete box girder. Investigations will determine whether enough hangers were in place when the pipeline collapsed.
A spokesman for the World Bank, which supplied nearly £120M of the funding for the bridge, also denied reports that it had censured the Bangladesh Government for the failure to allow adequate time to complete the gas main installation. 'As far as we are concerned the bridge is already a proven success,' he added.
Supplies of gas to Bangladesh's hitherto isolated western zone were not delayed by the accident, as the land infrastructure was not in place. It is now expected that Hyundai will have completed installing the replacement main in time to connect into the new land main in early February.
Toll revenue is already 31% up on predictions, with nearly 2,500 vehicles using the bridge every day. And during the recent massive floods the crossing provided the only link across the Jamuna as ferries were unable to operate.