Guaranteeing success in the world’s longest tunnels
The huge strides made in tunneling techniques in recent decades have allowed engineers to overcome formidable natural barriers, and these mega-structures continue to push further and deeper, with a string of technically-impressive projects underway or planned around the world.
“Today’s rail passengers and rail operators increasingly expect to have uninterrupted access to mobile and high speed internet services.”
However, it is no longer enough to only successfully operate trains through these long tunnels. As Roland Leucker points out, “today’s rail passengers and rail operators increasingly expect to have uninterrupted access to mobile and high speed internet services while on the train, even while they travel underground. Safety standards are also much more stringent in part due to the requirement to maintain a constant radio signal onboard trains travelling at up to 250km/h in highly-pressurized environment. Tunnels therefore have to be fitted out accordingly to provide these services as reliably and effectively as possible.”
Alcatel-Lucent is currently undertaking some of the most important and technologically innovative tunnel communications projects in the world, including the 57km Gotthard base tunnel in Switzerland, which will be the world’s longest when it opens in 2016. It will also arguably be the most technically advanced ever to be constructed. This will be largely due to the integrated communications systems that have been planned, designed and implemented by Alcatel-Lucent. The work started very early on with the various consortium partners offering to the end customer a state-of-the-art finished product but also, offering the construction partners a safe and secure environment during the construction stage, for what is still in the 21st Century a high risk endeavor.
Managing and forming the right relationships
While installing a reliable and efficient communication system in the world’s longest tunnel is certainly a major undertaking, Rolf Sigrist from Alcatel-Lucent’s global centre of excellence for tunnel/rail says that the greatest challenge he has encountered during the Gotthard project is managing relationships with all the different parties involved. Unlike most of its previous railway projects, Alcatel-Lucent has worked on the tunnel as part of a larger consortium. This meant the company had to manage relationships with not only its partners and subcontractors, but all other parties involved in tunnel and railway construction, overcoming what Sigrist describes as “a clash of industry cultures”.
“We know how to dealing with anyone from tunnel excavators to track-laying companies whose part of the story is completely different.”
“We know how to deal with anyone from tunnel excavators to track-laying companies whose part of the story is completely different,” Sigrist says. “After years of working in this environment, we are used to a multi-vendor management and integration projects and have learnt a great deal from it.”
The scale of this type of project, which can take up to 10 years to complete, also means that forming the right relationships and partnerships with subcontractors is essential in the very early stages to avoid difficulties down the line. In the Gotthard project for instance, thousands of interfaces (whether electrical, mechanical, system) are required for reliable operation, all of which are transmitted to and integrated at the tunnel control centre managed by Alcatel-Lucent. Sigrist says that work began to form these partnerships up to a year before the RFQ was issued, which he says was critical in getting experienced partners on board.
“You have to be careful who you get into a contract with,” Sigrist warns. “In many ways it is like getting married. You have to anticipate potential obstacles or problems and mutually work on a common solution, find ways to solve the issues, and very often reach a compromise that will produce the end result. We have found that working in such a way cements the relationship with our partners, making us even stronger for when we might work together again.”
Empowered Control Centers
In addition to monitoring communications, the control center can also be responsible for screening the performance of the tunnel’s entire infrastructure, from energy use to access doors. For this to work effectively in the Gotthard Tunnel, Alcatel-Lucent developed an expert system to correlate all telecom alarms and minimize the number of processes in order to focus on the root cause. “In fact in the Gotthard project, there are approximately 70,000 data points to the tunnel control center, all of which need to be handled effectively so all relevant information is displayed and easy for operating personnel to understand.”
With so many subcontractors to work with, managing the installation of the systems and interfaces in any complex tunnel project is a difficult process that requires an established and expert partner. Sigrist also emphasizes that it is important that the technology used remains up-to-date. “The installation can take more than five years to complete and of course during that time there will be updates to the technology used, and also fluctuations in price and functionality.”
Inevitably there are a number of significant challenges once construction gets underway. On a tunnel that is 57km in length and with just two access portals, reaching the work site is a challenge in itself, particularly as work progresses, with workers entering in the morning and often not able to leave the tunnel before the end of the day.
“Minimizing the number of components is integral for a piece of infrastructure on which maintenance might only be able to be carried out during four-hour windows at night on the weekends.”
Working conditions are also far from ideal. No air-conditioning systems are installed in some rail tunnels because once it is operational passing trains move sufficient air to ventilate the space. Temperatures can consequently reach up to 45˚C, as they will during operation on the Gotthard tunnel. With this in mind, Sigrist says that from a technical perspective Alcatel-Lucent had to select equipment capable of operating without cooling systems to minimize energy consumption as well as the number of components that might fail.
Indeed, minimizing the number of components is integral for a piece of infrastructure on which maintenance might only be able to be carried out during four-hour windows at night at the weekends. In the Gotthard tunnel, all of the data backbone, tunnel radio equipment and voice communication equipment, along with emergency phones, were installed in the cross tunnels that are situated 325m apart between the two running tunnels. Alcatel-Lucent made sure during design phase that the major parts of the telecom equipment are only located in the two multifunction stations in the tunnel and at the two portals. This simplified approach was also adopted through the use of a single leaky cable in the tunnel which can carry the GSM-R, public GSM, UMTS and professional mobile radio (PMR) systems used by emergency services.
Infrastructure renewal unlocks innovation
While new construction is designed with installation of reliable telecommunications systems in mind, there is a growing demand to upgrade existing infrastructure to the latest standards. After nearly two decades of operation in tough conditions, Alcatel-Lucent is currently revamping the communications infrastructure of the EuroTunnel, which is the world’s longest undersea tunnel.
Like the tunnel itself, the renewal of the network is in many ways a pioneering endeavor. In December 2009, Eurotunnel selected Alcatel-Lucent as its partner for the rollout of GSM-R, which not only makes the tunnel interoperable with adjoining railways but delivers much greater flexibility in its communications architecture.
A key advantage of the GSM-R project is that it supports the rollout of a public GSM-P public network, and this summer the Channel Tunnel will be the first long tunnel in the world to provide 3G coverage throughout its entire length. Eurotunnel will make the retransmission infrastructure available to the French and British mobile operators for 2G (GSM 900 and DCS 1800) and 3G (UMTS 2100) services.
This has obvious benefits to passengers, who will for the first time enjoy seamless mobile connectivity as they speed beneath the Channel. It also gives rail a key competitive edge over its air and ferry rivals, demonstrating how Eurotunnel is continuing to innovate in service delivery.
Increasing safety and security
Inevitably safety is of paramount importance in a tunnel environment. One area where there has been significant progress in recent years is the general evacuation concept, particularly the improvement of surveillance systems. Alcatel-Lucent is responsible for RFID tagging devices being used in the Gotthard tunnel during construction which identify the location of anyone in the tunnel and provide vital statistics such as their name and job title to the control room. It is possible to extend this concept further through the installation of CCTV surveillance which, in an emergency, could help operators make a more informed decision to minimize potential risks.
While working on a tunneling project of such magnitude as the Gotthard base or Eurotunnel is a very challenging and demanding undertaking, it does have its rewards. Sigrist says that everyone working on the Gotthard Base tunnel feels an enormous sense of pride at playing their part in building what will be the world’s longest tunnel and a true engineering landmark, and the same can be said for the Eurotunnel before it opened in 1995. Indeed he says that working on such important pieces of infrastructure is an opportunity that does not come around very often.
“It is a fascinating project, and in many ways a once in a lifetime working experience that is very different from projects I have worked on previously with Alcatel-Lucent,” he says. “It is special and it is one of those things that you feel very proud to be a part of.”
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