What are bearing pads and why are they installed on bridges and metro lines?

After two bearing pads fell off Dhaka’s metro line in five weeks, questions mount over their structure, purpose, and safety standards

The repeated fall of bearing pads from Dhaka’s metro line -- twice within 13 months -- has stirred widespread curiosity about what they are and how they function.

Some have even asked whether a rubber-made pad could cause death upon impact. The last incident occurred on Sept 18 last year, halting metro operations but causing no casualties. This time, however, the fall proved fatal.

On Sunday, a pedestrian died after being hit by a bearing pad that fell from the Dhaka Metro Rail line in Farmgate.

Experts say these pads are much heavier than they appear. Used in bridges and flyovers to absorb vibration, elastomeric bearing pads are made from neoprene or natural rubber and are installed between the pier and viaduct joints. Some contain multiple internal steel layers, encased in thick rubber.

Kamrul Hasan, an engineer at the Roads and Highways Department, explained: “These rubber pads are used to create elasticity between a bridge’s pier and girder. They are both locally made and imported. Each pad can weigh between 50kg and 200kg. BUET tests their effectiveness before approval.”

The fresh incident has raised questions over whether authorities acted on the recommendations made after the September accident -- and if they did, why the failure recurred.

Faruque Ahmed, Managing Director of Dhaka Mass Transit Company Limited (DMTCL), said: “All necessary actions were taken as per the previous committee’s report. Every pillar was physically inspected by experts.”

Standing beside him at the scene on Sunday afternoon, Road Transport Advisor Fouzul Kabir Khan pointed and asked: “Then how did this happen?”

When asked if anyone had faced action after the earlier incident, Faruque replied: “It happened during the defect liability period, so the contractor was allowed to rectify it. They said the issue had been fixed.”

Faozul added, “The Japanese contractors did this. The current committee will also review the earlier report.”

He said a new five-member probe committee was formed around 12:30pm on Sunday at the Farmgate site.