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Denmark’s LRT revolution

One of the many new bridges for the Aarhus LRT project is this complex arrangement that extends over the existing railway towards the new depot and network management centre, seen in the background. Image courtesy of Aarhus Letbane.

Following a couple of false starts, the new tramway in Aarhus, Denmark, opened for business on 21 December 2017, returning steel wheel-on-steel rail service to the city following a hiatus of 46 years. The final parade of first-generation tramcars ran on the city’s metre-gauge rails on 7 November 1971.

As the first such installation of the mode in the country in the 21st Century, the first phase of this eventual 110km (68-mile) mix of standard-gauge tram and tram-train operation is the first step in re-establishing light rail in a nation that boasts some of the highest environmental credentials in Europe.

Aside from being a Danish pioneer, what makes the Aarhus project interesting is that it covers just about every application of modern light rail: street-running in mixed traffic, segregated rural sections, complex bridge construction and tram-train running.

Driving the green agenda

With a population of 330 000, Aarhus is Denmark’s second-largest city. Over the past ten years the largest population centre in the East Jutland region has welcomed 15 000 new residents and created 20 000 new jobs. Conservative projections suggest that by 2030 the city will grow by an additional 50 000 inhabitants, creating a further 30 000 employment opportunities and student places at the city’s expanding and world-renowned university.

The greater Aarhus city region is now almost as big as the capital region of Copenhagen, although its urban and interurban infrastructure is nowhere near as comprehensive. Yet given the city’s ambitions to establish itself on the world stage and move away from the private car in stimulating urban regeneration, it is therefore apt that its first tramline opened at the tail end of the same year that it celebrated its status of European Capital of Culture, under the theme ‘Rethink’.

Furthermore, decisions have been taken over the last two decades to increase the urban density by ‘condensing’ the city through the design and construction of high-rise development which will increase the number of people living in the core areas.

As a city struggling under the weight of congestion and its associated environmental impacts, a more efficient public transportation network is seen as essential. This forms part of wider policies to help meet both national and regional climate targets as the municipality aims to become carbon-neutral by 2030.

Addressing air quality, waste and related issues, Denmark has the highest environmental tax revenues of any EU country. Companies face large levies on potentially harmful products and emissions related to manufacturing and the discharge of pollutants, and there are also significant taxes attached to the exploitation of scarce natural resources.

There are plans to go even further. By 2020, half of the nation’s energy requirement will come from renewable sources, and greenhouse gas emissions are anticipated to be a third lower than in 1990. By 2050 the country plans to be completely independent of fossil fuels.

Meeting these targets at the same time as implementing ambitious growth strategies for its key urban areas requires a different approach to transport. The popularity of cycling sees 16% of all trips made on two wheels, with 36% of Danes cycling to work at least once a week. The Government uses fiscal incentives to increase the use of alternative modes, adding substantial taxes to the cost of new road vehicles.

With existing bus and urban rail services reaching capacity in many cities, trams and light rail are seen as key to not only reducing gridlock, but also as a catalyst for urban development to stimulate both public and private investment.

The move to LRT

The first consideration of light rail in Aarhus was undertaken at the start of the century, although it took nearly a decade for funding approvals and detailed planning to progress.

Following studies by COWI and SYSTRA, the scheme’s Environmental Impact Assessment was completed in 2010, and a key milestone was the passing of a Bill in the Danish Parliament on 8 May 2012 that gave legal powers for the project’s first phase.

Promoter Aarhus Letbane was established in August 2012 to develop an urban tramway loop and interface with the national railway operator for joint running over railway routes to the north and south.

Although Denmark has a well-established construction sector, it lacks expertise in tramway construction. The first utility diversions and preliminary works for the LRT project began in the spring of 2013, but it would be another year before a consortium of European partners could begin the first major construction works.

A Stadler and Ansaldo STS joint venture was appointed in the summer of 2014 to provide vehicles, electrification, signalling and railway systems ahead of the first major works beginning in October that year. This joint venture was later enlarged to include Italian lead contractor Generale Costruzioni Ferroviarie (GCF) – a firm with growing experience in all aspects of railway construction, maintenance and renewal
– for the trackwork, platforms and other civil works, as well as the Control and Maintenance Centre (CMC).

Civil works are costed at DKK1.9bn (EUR255m) with an additional DKK1.7bn (EUR226m) for rolling stock, railway systems and operations (DKK3.6bn total) – 47% of project funding is from the state, 47% from the municipality and 6% from regional funds. The European Investment Bank has provided DKK14.2m (EUR1.9m) as part of the European Local Energy Assistance programme (ELENA) to support construction and transportation projects that contribute to energy savings.

Stadler has delivered 26 low-floor vehicles for the new service, comprised of 14 Variobahn trams for the urban tramway
loop that has opened first and 12 Tango tram-trains for the converted railway sections to Odder in the south and Grenaa to the north that are planned to open later in 2018.

Constructed at the firm’s plant in Pankow, Berlin, the Variobahn cars are similar in design to those in service in Bergen, Norway: 32.6m long, 2.65m wide and with three double doors and a single door on each side of the five-section vehicle. Passenger capacity is 216, 84 seated.

The Tango LRVs are being built at the manufacturer’s factory in Altenrhein, Switzerland. These 40m-long vehicles are capable of 100km/h (62mph) operation and can accommodate 256 passengers, 108 seated. They have marginally higher floor heights to the Variobahn vehicles (+5mm), a different door arrangement and a slightly modified wheel profile to accommodate both urban tracks and the converted heavy rail infrastructure. They will share stabling and maintenance facilities.

Both vehicle types benefit from onboard wi-fi and charging points for mobile devices, as well as uprated HVAC systems and double-glazing to cater for operations in the region’s cold climate. Relatively moderate in terms of temperature shift (East Jutland varies from single-digit sub-zero conditions in December and January to around 20°C in the height of summer), rain is fairly evenly distributed throughout the calendar, with winter being the most humid time of year.

Although detailed investigations of catenary-free power supply were undertaken in the early stages of the project’s design, overhead line supply at 750V dc was chosen as the most suitable solution with careful design to limit visual intrusion of the system’s 29 substations and 3000 OLE support structures.

The routes in detail

The first section to open is the 7km (4.3-mile) route between Aarhus H railway station and Universitetshospitalet, with ten intermediate stops. The full 12km (7.5-mile) line north to Lystrup, including some interurban and rural running, will complete Phase 1. In such areas, construction was limited to certain months to avoid adversely disturbing wildlife conservation areas.

Once out of the city and along the harbourfront section, the mainly single-track-with-loop alignment has brought its own challenges, involving the conversion of existing regional railway infrastructure to light rail operation. New catenary and signalling systems have been installed, platforms have been lowered to accommodate the new Tango LRV fleet and electrification of these two lines – north to Grenaa (69km/43 miles) and south to Odder (26.5km/16.5 miles) – has been undertaken in partnership with national railway agency Banedanmark for 100km/h (62mph) running on the line to Grenaa. The Odder line will have a maximum speed of 75km/h (47mph).

Vehicles operate on line-of-sight principles within the city, while Ansaldo STS has installed Automatic Train Protection based on axle counters for the lines to Odder and Grenaa. EMC immunisation work has had to be completed on Banedanmark lines due to potential interference to legacy equipment. With the national rail agency’s nationwide ERTMS rollout due for completion in the region by 2020, a hybrid solution was developed to replace the legacy track circuits to significantly reduce the cost of full conversion of the system.

Eight new bridges have been constructed; with a combined length of almost 500m, and at a maximum height of 12m, most are on the northern section of the loop on the route to Lisbjerg, as the route extends over major motorways and the Egådalen river valley and nature reserve. All of these new structures are 15m wide with integrated cyclepaths.

As a sign that the LRT project is being built with one eye on the future, the village of Lisbjerg (population around 850) and the town of Lystrup (approx. 10 400) are both served. Land along the route to the north of the city is being snapped up by developers and dense housing estates are planned that will help to cater for the growth of the region.

Another bridge crosses a heavy rail yard to access the 27 000m2 (approx. 290 000ft2) CMC on the south-western outskirts of the city. The route to the CMC runs parallel to and is squeezed into available space between existing heavy rail routes.

A further important feature is the construction of a pair of new pedestrian tunnels to connect the University and Aarhus University Hospital on the Nørrebrogade throughfare. These brought additional complexity due to their proximity to the hospital’s delicate laboratory instrumentation. Initial tests showed that traditional sheet piling would cause potentially damaging effects to sensitive equipment, so a different technology was employed that increased both the timescale and cost. Nevertheless, Aarhus Letbane and its construction partners managed to complete both tunnels without applying any additional pressure to the tight schedule – and while maintaining good relationships with the neighbouring hospital.

Within the city itself, one small bridge posed significant construction challenges. Situated over a stream close to the city’s harbour, the bridge was required to carry twin tracks, one of them strong enough to accommodate a freight train, yet without compromising height under the bridge.

Otherwise, only minor adjustments have been made to the city’s streets, mainly involving laying new foundations to support slab track for the light rail tracks. Four types are used across the system: segregated sections use sleepers placed on stone ballast; paved track is used in the key urban elements and green track is used on more suburban sections. These three types are supplemented by the use of asphalt surfacing at the system’s numerous road crossings and intersections.

Predating the light rail project by two years, two new bus lanes were opened on the key northern Nørreport, Nørrebrogade and Randersvej thoroughfares. Having the bus lanes in place meant the original four-lane road configuration could be preserved when construction began on the double slab-track in the road median. In order to maintain service speeds, full signal priority is given on 17 of the key urban intersections,
with enhanced priority at two others.

Operations and the future

International transport specialist Keolis was chosen to operate the new system in May 2015, beginning the recruitment process for the 80 drivers required for the network later that year.

Testing began on the city section in July 2017. The opening date of 23 September (the second such planned date) at the landmark Dokk1 library and cultural centre on the harbourfront had to be called off at the last-minute following the refusal of the Danish Transport, Building and Housing Agency to give final approval for passenger service, stating concerns with safety documentation and maintenance procedures provided by the operator.

At the time, Thomas Friis Brændstrup, Managing Director of Keolis Aarhus Letbane, said: “It is the first light rail in Denmark, so we must acknowledge that, from all sides, there has been a learning process – this has only made Keolis Aarhus Letbane a stronger and smarter organisation. Now we are looking forward to seriously starting to run the system and thus helping to lift public transport in Aarhus.”

The opening hours of the new service are 05.00-01.00, seven days a week, with eight departures per hour in peak hours between Aarhus railway station and Aarhus University Hospital in Skejby. Ridership predictions are 39 000 passengers/day.

Tickets are purchased from platform TVMs (payment by card only) and validated via tapping-in or out upon boarding or alighting. Letbane tickets are integrated with the Midttrafik bus network, allowing for easy transfers, and the AarhusCARD offers discounted travel across city and regional bus services and airport shuttles, as well as free admission to city attractions and special offers at local shops and restaurants.

Adjustments have been made to the bus network to feed the new light rail service and provision has been made not only for bicycle parking at stops, but also with new cyclepaths along the light rail corridor between Skejby and Lisbjerg. A new park-and-ride site has been created in Lisbjerg.

The next phase of the project sees integration of services on the Odderbanen and the final approvals for this are due imminently. Delays have been caused on this section due to the line’s 21 level crossings, with a specific risk assessment required for each. Aarhus Letbane has adopted similar dynamic level crossing detection technology to that used in Lyon, France, where Tango vehicles are also in service. This system shortens waiting times by altering traditional trigger points, an important consideration given that there are 50 level crossings along the southern and northern heavy rail alignments.

Services on the northern section to Grenaa are expected later in the year.

Plans are already well underway for Phase 2, including an 8km (five-mile) route from Lisbjerg West to Hinnerup, a short spur into the new ‘Aarhus Ø’ residential and commercial district under development on the new harbourfront and a line to Brabrand, 11km (6.8 miles) west of Aarhus. These additional routes will bring more than half of the city’s residents, workplaces and educational institutions within easy reach of the expanding light rail system.

Elements of Phase 2 are still under evaluation and funding applications are still to be made, although planning is underway and the Environmental Impact Assessment is to begin in 2018, so it is likely that the short extension to Aarhus Ø could be realised first.

GCF’S EXPERTISE Generale Costruzioni Ferroviarie (GCF) is an Italian railway construction specialist, founded in 1950. Over the last decade it has grown its expertise from track construction into electrification, and expanded from many successful domestic contracts to develop international experience. The company now covers the design and construction of all facets of the modern railway – from tramway and metro systems to high-speed lines – including safety and signalling systems and renewal and maintenance projects. GCF’s competitive edge is based on its experience, organisation and vast equipment resource (more than 600 railway machines), with significant high production efficiency. In addition to main infrastructure works on the Aarhus Letbane, GCF has completed high-speed lines in Italy, over 3000km (over 1850 miles) of track renewal projects in France (2013-18), slab track and ballast tracks for Switzerland’s Monte Ceneri base tunnel; 30km (18.6 miles) of tunnel slab track and third rail installation for Copenhagen’s CityRingen; and track and OLE rehabilitation on the Plovdiv-Burgas line (Bulgaria) and the Ankara-Istanbul high-speed railway (Turkey). Find out more at

Thanks are due to Helge Bay, Jens Velling, Communication Manager of Aarhus Letbane and the team at Midttrafik for their assistance in the preparation of this article.

Article originally featured in March 2018 TAUT (963).