The Great Belt Fixed Link connects half of the Danish population with the rest of the European road and rail network. Approximately 11 million vehicles and 8,3 million train passengers cross the bridge each year. A new 2 x 1 Gbit/s fibre backbone network was recently installed to provide for all the data transmission from the weather stations and CCTV, and a new emergency phone system using IP telephony technology was installed. To provide the data communication between the telephone and the fibre backbone, the company A/S Storebælt has chosen the robust Westermo Wolverine Ethernet Extender.
The construction started in 1988 and in 1997 the connection was first opened for railway traffic. One year later, in 1998, the fixed link was completely finished and opened for road traffic as well. State-owned company A/S Storebælt were tasked to keep the link operational at all times, all year around and in such condition that it could be used for more than a 100 years.
The fixed link consists of a 6.8 km suspension bridge (East Bridge), a 6.6 km box girder bridge (West Bridge) and a railway tunnel. All together, the link is 18 km long. A state-owned structure of this massive scale calls for extreme commitments when it comes to safety. Alongside the bridge there are numerous CCTV cameras and seven weather stations that constantly report changes in wind and weather and emergency phones can be found in both directions along the motorway at least every 600 metres.
Since the bridge has been in use for more than 10 years, an upgrade to the safety systems were required. The old backbone network had a transmission capacity of 2 Mbit/s, and while this system provided sufficient bandwidth, it could no longer be serviced. A new 2 x 1 Gbit/s fiber backbone network was installed to provide for all the data transmission from the weather stations and CCTV, and a new emergency phone system using IP telephony technology was installed.
The old emergency telephone system was insufficient in several ways. First of all the cabinet that held the telephone receiver was not robust enough for the harsh climate out on the bridge. Exposed to all kinds of weather all year around for ten years, the aluminium cabinets were severely corroded, making the phone unusable.
Another problem with the old system was that all calls were connected directly to the police alarm centre in the nearby town of Slagelse, regardless of the help needed. 9 out of 10 calls are made because of people running out of fuel, and not real accidents. A vehicle standing still on the bridge could however lead to a serious incident, so the policy is to get any vehicle standing still moving again in the least time possible. In these cases, A/S Storebælt has found that the quickest way of getting a stranded vehicle out of harm´s way is to simply provide fuel or a tow for free.
The new IP emergency phone system connects all calls to the A/S Storebælt control centre, so that fuel breakdowns can be taken care of by their own staff, and emergency calls that are made because of an accident can easily be forwarded to the police alarm center.
Another improvement is that the new system can forward the exact location from where the calls are made, something that was impossible with the old system. This leads to a much faster rescue process and a higher level of security.
New telephones made from a more weather-resistant aluminium alloy were installed, and to provide for the data communication between the telephone and the fiber backbone, A/S Storebælt chose the robust Westermo Wolverine Ethernet Extender. The Wolverine utilizes SHDSL technology over many types of twisted pair cables, and can provide data rates of up to 15.3 Mbit/s. Another great benefit that comes with the Wolverine is that existing cabling can be used, thus making great savings on installation. In this case, the cables from the old telephone system could be used to carry the data for the IP telephone system, resulting in huge financial savings.
31 Wolverine units have been installed along the full length of the bridges, and each device connects to two telephones at one end, and to the backbone network at the other.
Besides that the Wolverine was the perfect fit, the decision to go with a Westermo unit was based on positive results in previous projects, and that the products are considered robust, easy to use and problem-free.
Westermo provides a full range of industrial data communications solutions for demanding applications in the transport, water and energy markets among others. For more than 35 years Westermo has been at the forefront of technological development and often pushed the limits of what is technically possible. In order to provide the best possible support, we have local presence in more than 35 countries through our authorized distributors and own offices. Since 2008 Westermo has been part of the Beijer Electronics Group, a fast growing technology company with extensive experience of industrial automation, developing and marketing competitive products and solutions with focus on the user.
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