Design Flaws, Substandard Bearing Pad Behind Farmgate Metro Accident: Probe
An investigation committee has found that design flaws in the metro rail alignment and the use of substandard bearing pads led to the accident beneath the Farmgate metro rail line at around 12:20 pm on October 26, when a bearing pad fell and caused a fatality.
The findings were disclosed by Road Transport and Bridges Ministry Adviser Muhammad Fawzul Kabir Khan at a press conference at the Secretariat on Thursday (January 1), following submission of the investigation report. He said the committee found no evidence of sabotage behind the incident.
Receiving the report ahead of the briefing, the adviser said preliminary findings indicated that the hardness, compression set, and neoprene content of the dislodged bearing pad did not meet prevailing standards. However, he noted that further testing at overseas laboratories would be required to conclusively verify the results.
The committee also observed that the bearing pad had been installed with a slight slope of 0.8 percent, which is believed to have contributed to its displacement.
Adviser Fawzul Kabir Khan said the Farmgate metro station has circular alignments at both ends, and the investigation found that no transition curve had been used between the straight and circular sections of the viaduct alignment. This indicates a possible design flaw in the metro rail alignment. Separate modelling and analysis were not carried out for the curved alignment; instead, the design was based on modelling and analysis meant for straight alignment sections.
He further said vibration measurements taken during train operations showed significantly higher vibrations at piers associated with the displaced bearing pad—specifically Pier No. 430 and Pier No. 433—compared to other piers. The committee believes that unwanted lateral forces and vibrations, arising from potential design flaws in the curved alignment, are linked to the bearing pad displacement.
The investigation also found that while a neoprene rubber mass-spring damper system was used beneath the rail tracks at curved alignments and nearby stations, the section where the accident occurred used a rigid track system. The committee believes that installing mass-spring damper systems at such locations could have reduced vibrations. However, it reiterated that no sabotage-related activity was found.
Presenting the committee’s recommendations, the adviser said urgent technical measures must be implemented to prevent bearing pads from shifting at curved alignment sections. These measures are currently being implemented by Dhaka Mass Transit Company Limited (DMTCL).
To conclusively determine the cause of the bearing pad displacement, the committee recommended a detailed review of the viaduct’s structural design and track design through in-depth analysis by a third-party independent consultant. It also advised conducting a third-party safety audit of the overall metro rail project design.
Additionally, the committee recommended the rapid installation of an effective structural health monitoring system for close observation, alongside efforts to enhance institutional capacity within the metro rail authority and ensure technology transfer from foreign consultants to local experts.
The press conference was attended by the investigation committee’s chair and members, including BUET Mechanical Engineering Professor Dr ABM Taufiq Hasan, MIST Civil Engineering Associate Professor Lt Col Md Zahidul Islam, and BUET Civil Engineering Professor Dr Khan Mahmud Amanat.
The accident occurred on October 26 last year, when a bearing pad fell from the metro rail structure at Farmgate, killing a pedestrian named Abul Kalam, who was walking along the footpath at the time. A probe committee headed by Bridges Division Secretary Mohammad Abdur Rouf was formed on the day of the incident.
DBTech/JNU/EK/OR
