Road tunnels are one of the greatest achievements of engineering, made possible by advances in civil engineering and technology. On 29 March 1999, a fire in the Mont Blanc Tunnel, which links France and Italy, left 39 dead. Experts concluded that if the safety systems had been working properly, there most likely would not have been any loss of life. As a result of the tragedy, various changes were made to European tunnel regulations.
In 2013, construction of the Macrotúnel de Acapulco began. The tunnel spans 3,200 metres in length and at the time of completion was Mexico’s longest.
Actica Sistemas was awarded the majority of the technology and safety system lots, which involved HMI (SCADA); CCTV; automatic incident detection; linear temperature detectors; data outstations; meteorological stations to detect weather conditions around the tunnel; fire protection system; access control; communications and control centre; lighting control; climate control; variable message signs; ventilation control; conventional fire detection; loudspeakers, SOS systems; radiocommunications and energy management.
For this project, Actica played a key role in improving the design of the tunnel and implementing the technology it uses. The engineering team was guided by Spanish Royal Decree 635/2006, NFPA 502 and their experience in system integration. Success was achieved by optimising the basic design, making the very most of this regulation and standard, and using all our ingenuity for integration. I was responsible for the engineering work and detailed design of the tunnel’s technology systems.
A number of significant improvements were made, such as getting rid of an entire pump house (including its pumps and water tanks), connecting various systems and making certain changes to the inside of certain equipment.
Perhaps one of the most important of these improvements involved the conduits for the wiring belonging to the various systems. These steel conduits were to run along the sidewall of the tunnel and would be exposed to extreme moisture and salinity. Apart from being unsightly, they would have corroded over time and would have had to be repaired/replaced.
PVC conduits submerged in concrete were proposed and accepted. The problem was that the concrete lining was going to be poured the following day, and the civil engineering team needed the drawings for the new design straight away. We ended up having to do all the engineering work and drawings in just one night. The following day and without having slept, we handed the drawings for the new design over to the Head of Civil Engineering, who had no choice but to stop the concrete from being poured and order the new conduits be put in place.
Not only did we prevent the tunnel from having an unsightly appearance and avoid future maintenance issues, we also significantly cut costs by replacing thousands of metres of steel conduits with PVC ones.
Teamwork, determination and ingenuity were all key factors in making this project a success.