Zitron to Supply Fans for World's Biggest Underground ProjectThe M-30 motorway in Madrid is a large thoroughfare built in the seventies between Manoteras junction and Los Franceses bridge, and the ring road was completed in the mid nineties in the north of the Spanish capital. It has a capacity to hold more than 300,000 vehicles a day and is used by approximately 500,000 users. A great amount of traffic is facilitated, both internally from the heart of Madrid or interior nucleus of the M-30, as well as the accesses to the city from outlying areas. The upgrading of the M-30 is one of the main urban projects undertaken by Madrid City Council, redesigning the motorway and the area it runs through in two phases. The project owner and operator is Madrid Calle 30 (or Madrid Street 30 as the project is also known), a company controlled by Madrid City Council (80%) and Ferrovial, Dragados and API Conservacion (20%).Phase 1 (marked in red on the map) will take a period of three years to build from 2004 to early 2007. The second phase (in blue) will be undertaken during the period between 2007 and 2010. The new motorway will improve the service of the M-30, reducing journey times, creating new green spaces and regenerating the Manzanares river to serve the people of Madrid.Among the works included in Phase 1, five have now been completed and opened: Costa Rica interchange linking with the M-30, including a 190 m-long tunnel designed to be extended after 2007, the lengthened O'Donnell tunnel, the link to the A-2, the M-30 south exit to the A-3 and La Paloma interchange linking the M-30 with Pio XII and Burgos avenues, including two tunnels of 405 and 209 metres.Work under construction, which is programmed to be finished by late 2006 or early 2007, covers all the work in the south and west area of the M-30. The southern zone of the M-30 is carried out under nine tenders, reaching over 45 km of tunnel including links. Two of these steps correspond to the bypass that links Praga bridge with the A-3, and which are being built using two TBMs. These TBMs, currently the largest in the world, measure 15.2 metres in diameter and have a thrust capacity of over 31,000 tonnes and can bore 24 metres daily. Click here and here. The fact that its size is so great, along with the traffic density involved, have led to plan all the work undertaken in the tunnels with one objective in mind: safety. The importance of safety affects the whole project, including construction, coordination and control (from energy, ventilation, fire protection, radio communications, signs, everything down to the last cable used). Regarding ventilation, 165 high power axial fans, 270 back-up extractor fans and 470 blow fans will be designed and supplied by Zitron. In addition, in the extraction shafts there will be 30 particle filtering stations and four stations for filtering nitrogen dioxide. Click here. View pictures here. Visit www.zitron.com The ventilation system in Madrid's southern bypass, which consists of two one-way tunnels of 4,200 metres each, is completely transversal blowing fresh air inside from a lower platform and extracting it through the upper. Therefore, four large ventilation tanks will be built. There are four large ventilation shafts for the two tunnels.For the other tunnels, which are built in cut-and-cover, the ventilation system will also be transversal with blow fans which will help lengthwise ventilation if necessary. The installation of smoke extractor fans along the tunnels is also foreseen.Ventilation control will be carried out using the information collected, i.e. mainly opacity, CO and NO2 detectors, situated at every 300 metres and anemometers every 100 metres.This year, Madrid Calle 30 will start the proceedings prior to the future bidding of the construction of the second phase, including the lengthening of the Santa Maria de la Cabeza tunnel, the north/Ilustracion Avenue bypass (east and west tunnels) and the connection of the north bypass to the A-1. Click es/104. 18/06.