The holiday season in Nigeria is a period when people travel, especially from the city to the countryside to celebrate with relations. At such moments, the River Niger Bridge which links the Southeast with the rest of the country through Onitsha in Anambra State and Asaba in Delta State in the South-south is usually stressed because of the load it carries.
At such periods as in other times, the bridge carries stationary loads far beyond its capacity for many hours and sometimes days as traffic builds up on the structure from both ends. The situation is usually created by the activities of security agencies which conduct checks on vehicles and other road users on the approach to the structure, especially at the Onitsha end.
The security agencies which mount checks in the area include Nigeria Police Force, Federal Road Safety Corps (FRSC), Nigerian Army, Department of State Services (DSS) and National Drug Law Enforcement Agency.
The development is raising huge public concern about the integrity of the structure and safety of road users, who fear it might collapse at any moment because of the load it carries and the vibrations that they experience on the bridge.
The bridge was built by Dumez Engineering, a French Construction firm, in 1965. The dimension of the bridge is 8×420ft with a carriageway of 36ft centre-truss and a pedestrian walkway on both sides.
The last major rehabilitation work on the bridge was carried out by the administration of President Goodluck Jonathan (2009-2015).which replaced the two spans on the Onitsa end of the bridge which were damaged during the 1967-1970 Nigerian Civil War with a 14ft wide bailey,
The public are worried that the vibration experienced on the bridge is abnormal and are afraid for their safety on the bridge.
If the structure collapses, all states in the Southeast – Anambra, Imo, Enugu, Abia, Ebonyi- as well as Rivers, Cross River, Akwa Ibom and Bayelsa states in the Niger Delta or South-south region will be cut off from the rest of the country.
Nigeria has recorded 90 cases of bridge collapse in the last 20 years, is according to a study by Anthony Ede on metals, entitled, “Failure Trend of Transport Infrastructure in Developing Nations: Cases of Bridge Collapse in Nigeria”.
The study blamed the collapse of the bridges on flood, overload, terrorism action, design and construction errors as well as the lack of proper inspection and maintenance.Mr Andrew Kumapayi, the Sector Commander of FRSC in Anambra State, said there were five major causes of gridlock on the bridge.
Kumapayi said the causes included lane indiscipline where motorists encroached on the lane meant for vehicles going to the opposite direction instead of the two lanes which vehicles on each direction were meant to use.
He said other factors were activities of commercial tricycles operators who obstruct traffic at the Asaba end as well as Asaba bound commercial vehicle drivers who load at the entry point of the bridge in Onitsha.
He said another reason was that motorists often preferred to repair their broken down vehicles on the bridge rather than tow them off for repairs in addition to the lack of patience by drivers who overtook without caution.
“The proliferation of agencies which conduct various checks on vehicles just after the bride in Onitsha is uncalled for. A situation where the police, army, DSS, FRSC and other agencies all checking vehicle at the end of the bridge contribute immensely to hold up on the bridge,” he said.
Kumapayi suggested that all activities around the bridge be moved not less than 200m away from both ends of the bridge to avoid traffic building up on the structure.
He said he had been reliably assured that the integrity of the bridge was intact as the design provided that there would be some slight movement on the structure.
“On the part of FRSC, I have instructed that under no circumstances should my personnel stop, inspect or book vehicles anymore; as a matter of fact, the instruction is that they should move 200m away from the bridge to conduct those checks. I encourage other sister agencies to do same.
“FRSC is not comfortable with gridlock and heavy load on that bridge but as for the shaking that is noticed, experts say it was designed that way.
“The Federal Controller of Works in Anambra State, Mr Adeyemo Ajani,, has gone there with us and assured us that it meant no danger, but flow of traffic will help protect the bridge,” he said.
On his part, Ajani said the bridge was not in any danger, adding that there was nothing wrong with it in terms of structural stability.
He said there was extensive repair and maintenance work on the bridge between 2005 and 2006.
Ajani said the vibrations were normal and part of the design because the bridge had fixed and rocker bearings to allow for longitudinal thermal movement.
He said the government had not abandoned the bridge and that very soon a new asphalt overlay would be done on the bridge.
Dr Celestine Ezeagu, a civil engineer and lecturer at Nnamdi Azikiwe University, Awka, said every civil structure like the River Niger Bridge was designed to have a lifespan after which the integrity would be reviewed and fortified.
Ezeagu said the bridge might have been built with certain traffic load in mind but that 50 years after and increased population and commercial activities, the current load and vehicular traffic had far surpassed the original design.
He said the bridge ought to have echo monitoring devices which would help to determine its safety by
monitoring vibration from load, water, waves and current as well as vibration from shift in the foundation from a combination of the forces.
Ezeagu said while the public outcry on possible danger on the bridge might not necessarily mean that there was real danger, it was important that the Federal Government conduct a scientific test to arrive at an informed judgment on the integrity of the structure.
“I do not know if these echo monitoring devices were incorporated in the design and construction of the bridge, that is what we should be relying on for informed assessment of the stability of the bridge and not public outcry based on layman’s perception as have been seen in recent times.
“They should conduct the integrity test and give us the percentage reliability or deviation from the original position.
“It is not enough to just tell us the bridge is stable, all cannot be well at the same time. They should be able to tell us the area of the bridge that needs to be strengthened,” Ezeagu said.
He said bridges were not designed to carry ‘steady and point’ and urged the relevant authorities to do all that was necessary to ensure that the Niger Bridge was free at all times to protect it.
“Bridges are built for mobile axial load and not for point and steady load. Bridges are like ladder, we use them when they are needed and close them when not needed; in some places they are adjustable or folded.
“It is a strategic and expensive infrastructure that should be protected. They should stop allowing vehicles to stay on the bridge. Some size of load should not be made to pass on that bridge, such loads should be moved through water,” he said.