Recently concerns have been raised about the safety of the Bailey bridges that have been used in many places around the country, including in the districts of Samara and Nosara.
The modular Bailey bridge over Montaña River that connects the communities of Nosara and Ostional has the same technical specifications as the bridge that was installed over Guaria creek in the Autopista General Cañas (Route 1), which collapsed on November 6, 2012 when an apparently overweight vehicle was crossing it. This was confirmed by Jose Luis Salas, executive director of the National Roadway Council (CONAVI- Consejo Nacional de Vialidad).
After this event, the quality and security of the Bailey bridges has become a topic of national discussion. A study from the National Laboratory of Structural Models and Materials (LANAMME) of the University of Costa Rica (UCR) revealed that the quality of steel in the latest modular Bailey bridges bought by the Costa Rican government don’t meet international standards.
The report on the “verification of the mechanical properties of the steel employed in the fabrication of the bridge” shows inconsistencies in the bidding cartel for MOPT, with which the last purchase of bridges took place.
The report explained that the “axial stress tests of the steel” performed by LANAMME revealed that the resistance of the material purchased in this last bid is of “a lesser grade” than other purchases previously made.
It appears to have been “an error” in the drafting of the bid by CONAVI as well as the Ministry of Public Transportation (MOPT), so they can’t complain to the company Mobey, provider of the structures, since the company met the specifications requested by the government.
Among the bridges that were acquired by this last purchase is the bridge over the Montaña River in the district of Nosara.
Aside from this, other Bailey bridges exist in the district of Samara, but according to Salas they weren’t part of this last purchase. These include the bridge in El Torito that connects Samara with Carrillo, the bridge over Buena Vista river in route to Samara near the Las Vegas bar and the bridge over Rio Frio by the community of El Silencio. However, Salas said not to worry as he guarantees that there is no problem that endangers the safety of those who travel across the structures.
In reference to the bridge over the Montaña River, he explained that the capacity of the structure is 200,000 cycles, which equates to the passing of 200,000 vehicles of 4 or 5 axels. According to Salas, once this quantity of vehicles has crossed the bridge, the slab of the floor of the structure will be replaced and it can continue to be used as normal.
According to data from MOPT, the price of each Bailey bridge is around 750 million colones ($1.5 million); however Julio Viales, regional director of MOPT, said that building a permanent cement bridge would involve a minimum investment of 1.2 billion colones ($2.4 million), and he believes that is way beyond their reach because the government isn’t willing to invest this amount of money. Viales was also critical of the work done by LANAMME since “they’re never there to prevent but rather when the blunder is already made,” he affirmed.
As for LANAMME, it recommended that both MOPT and CONAVI review the minimum yield stresses of the materials currently specified in bidding cartels.
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