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Ethernet switches boost emergency phone availability in Italian tunnel07 July 2008A sustained campaign across Europe to improve safety in tunnels has seen significant improvements made in recent years. As an example of the measures being implemented, GarrettCom Europe is supplying Ethernet switches and network management software for VoIP (voice over internet protocol) emergency telephones being installed along a 3.7km tunnel in ItalyA sustained campaign across Europe over the last five years has driven tunnel safety to the top of the agenda as a key motoring issue, impacting not only personal safety but also of whole countries’ transport infrastructure. Nowhere is this taken more seriously than in Italy, where on March 24 1999, a horrific fire in the Mont Blanc tunnel linking Charmonix, France with Courmayeur, Italy, resulted in the deaths of 39 people. A shocked government and public alike raised questions as to the safety of other tunnels in the country, where 75% of the terrain is classified in mountainous and where use of road tunnels is a daily fact of life.
Tunnels provide many of the primary links between Italy and France through the Alps, as well as with Switzerland. And there are many road tunnels across the rest of the country, including some of the world’s longest.
Fires can be lethal in road tunnels, where heat can build up extremely quickly. Across Europe, tunnel fires have killed over 90 people in the last ten years. This was one of the driving factors in the set-up by the European Commision of EuroTAP - the European Tunnels Assessment Programme. EuroTAP was established to test tunnels across Europe, and to make recommendations for safety systems and procedures.
Among the many measures identified by EuroTAP was the need for an effective network of emergency telephones throughout a tunnel - not only to provide fast warnings to emergency services in the event of a fire, but also to provide reliable communications points for the public in the case of accidents or breakdown. The integrity of this SOS telephone system is paramount, since mobile telephones are unlikely to work deep in the heart of a tunnel. Yet the failings of conventional technologies were visibly demonstrated to the world in May this year when, in a 22-car pile-up in the Harvey Tunnel in New Orleans that saw 24 people injured, none of the emergency telephones were found to be working.
In Italy, the Mont Blanc incident provided the stimulus for a series of research and development projects, aimed at optimising safety conditions in tunnels. Recent years have seen a host of Italian companies and universities active in ITS research and development projects associated with tunnel safety, focusing on innovative components and integrated systems.
Much of this work is already coming to fruition in both new tunnel projects and in reconstruction projects on existing tunnels. One example is the installation of a new VoIP (voice over internet protocol) emergency telephone network, installed by Italian system integrator Fort Fibre Ottiche, using VoIP phones from Teleindustria in conjunction with hardened Ethernet switches from GarrettCom Europe.
Teleindustria produces a wide range of emergency telephones, including models specifically developed for use in tunnels. This most recent project sees the company’s VoIP telephones deployed along 3.2km of tunnel at 250m intervals. Each telephone is connected to an associated GarrettCom ES42H Ethernet switch.
The ES42H is an industrially hardened version of the standard ES42 Ethernet switch, using high-grade components and constructed using a ruggedised metal case to deliver absolute reliability in the most demanding environments. A key feature is the use of patented thermal techniques which mean that no airflow is required for cooling, allowing the switches to be constructed impervious to dust, dirt, moisture, smoke and insects. These features make the ES42H an ideal choice for use in tunnels, and were a key factor in their selection for this application.
The compact design provides six Ethernet ports including up to two 100Mb fibre ports. The fibre port choices cover all multi-mode and single-mode fibre connector types.
For use in the tunnel, ES42H models were selected suitable for operating directly off the mains power supply, and offering the highest speed and bandwidth over single-mode network.
The switches are linked over fibre on twin ring networks - with the VoIP phones divided evenly over the two rings. Both rings connect ultimately to a GarrettCom 6K8 managed Ethernet switch which connects the VoIP phone network to an IP-PBX (internet protocol private branch exchange), and from there through a gateway to the normal public switched telephone network (PSTN).
The hardened switches ensure the highest degree of operational reliability, but the ruggedness of the network itself is further enhanced through the use of GarrettCom’s S-Ring technology, delivering high speed fault detection and correction. The S-Ring software runs on the 6K8 switch and monitors the ES42H switches on the two VoIP telephone rings, offering fast recovery in the event of a network break. Should the ring be interrupted, S-Ring acts immediately to change the ring into two topological strings, ensuring that there is a path through the two strings for all normal data traffic. Where the commonly used network recovery technologies offer recovery in around three seconds, S-Ring ensures network recovery in just 250m/sec.
Work such as this will play a key role in raising the levels of safety in tunnels, at a time when road traffic is increasing exponentially and when the potential for accidents is higher than it has ever been. And the importance of such work is witnessed by the fact that the EuroTAP programme has just completed its 2008 inspection of 31 European tunnels, concluding that there is still much work to be done across the whole of the continent. Contact Details and Archive...Related Articles...Most Viewed Articles... |
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