VAL Mini-Metro Line

Rennes is a small city in Western France, but with a population of just under half a million is Brittany’s largest dwelling. In 2002 an extensive metro system was launched and on the back of its success, plans for a second high-tech underground line are now underway. It was confirmed in July 2008 that €1bn will be spent on creating a second route as well as an additional €1,206m on adding to the existing infrastructure.

Background

After a long political battle it was decided in 1989 that a VAL (Véhicule Automatique Léger) mini-metro line similar to that operating in Lille was the favoured option for developing the city’s transportation. Opposition to the plan centred on the fact that other cities, such as Strasbourg and Rouen, were choosing to build cheaper tramway-style light rail systems. Instead, Rennes wanted to install a VAL system which is a driverless, rubber-tyred metro, invented by the French firm Matra and already in operation in Lille, Orly airport in Paris, Toulouse, Chicago and Taipei.

Vigorous opposition to the original scheme, much of which would have been elevated, saw the design of the route changed in 1990 and a further battle about funding for the line saw progress delayed until 1993.

Despite the best efforts of the French central government and environmentalists, a declaration of public utility was granted in October 1996. This declaration allowed work to commence in January 1997.

Costing considerably more than originally forecast due to the lengthy delays, the final total was €527.17m, including €164.6m for the VAL vehicles and systems, €221.35m for civil engineering work and €23.06m for other costs.

Finance for construction came from central government (€56.83m), the city of Rennes (€21.8m) and private finance (€238.88m), with other sources providing €130m.

More than a decade after it was first authorised, the Rennes VAL carried its first passengers in March 2002. French transport group Keolis was responsible for the line’s operation until December 2005. The metro line is part of the STAR (Service de Transport de l’Agglomération Rennaise) public transport network which serves the Rennes Métropole area.

Rennes VAL infrastructure

Rennes VAL consists of a single 9.4km-long route, 8.5km of which carries commercial services. The remaining 0.9km links the southern terminus at La Poterie with Chantepie depot.

The line runs roughly north-west from La Poterie via the city centre to Villejean University, terminating at JF Kennedy. Starting at the southern end, the line runs on a viaduct for around 1km, diving into a cut-and-cover section just before Le Blosne. From Clemenceau to Anatole France, the line runs in a bored tunnel under the city centre. On average, this section is around 16m underground and construction was disrupted by the difficult geology of the area. During tunnelling, several cases of subsidence emerged, some creating holes in the city’s streets.

Tunnelling was completed in March 2000, by which time much of the rest of the construction work was nearing completion.

Emerging from the bored tunnel after Anatole France, the line has another brief elevated section before returning to a cut-and-cover tunnel from Villejean University to JF Kennedy.

A major feature of the VAL system is that it allows steep gradients. In Rennes the maximum gradient is 8%. Adhesion is not a problem as it would be with steel-wheel-on-steel-rail systems.

Tracklaying commenced in April 1999 with French trackwork specialist Cogifer laying around 80m per day.

Test running started in July 2000 with driverless trials commencing that October. Journey time is 16 minutes from end to end, with an average speed of 32km/h. The line is designed to carry 70,000 people a day. However, it is now estimated that up to 125,000 passengers use the service every single day.

VAL stations in Rennes

A total of 15 stations have been built, averaging one every 611m. Each station has been designed by a different architect to emphasise individuality. All except La Poterie were designed by French architects; the southern terminus and adjoining bridge over the city’s ‘peripherique’ road were designed by British architect Lord Norman Foster.

Each station has platform edge doors to protect passengers and improve their environment. Trains automatically stop alongside the doors.

Rolling stock

Unlike other types of metro or light railway, the VAL system utilises rubber-tyred vehicles running on steel plates. Guidance is provided by horizontally fitted tyres in front and behind the driving axles.

Rennes uses VAL 208 vehicles, which are slightly lighter and wider than older VAL 206s used in Lille.

Although earlier VAL systems were built by Matra, by the time Rennes was ready to receive its trains the French firm had been taken over by the German giant, Siemens.

16 two-car VAL 208 vehicles were delivered to Rennes in 2000 but, unlike previous vehicles, they were constructed at Siemens’ former SGP plant in Vienna, Austria. Other components were sourced from France and Italy with bogies coming from
Switzerland.

The two-car trains carry 50 seated and 108 standing passengers and access is via three sets of double sliding doors on each car.

Maximum speed is 80km/h, although normal service speed is 60km/h. Acceleration is rapid at 1.3m/s² and braking is regenerative to reduce energy consumption.

Power is supplied at 750V DC via a side contact rail. One unusual feature of the VAL system is a central steel guidance wheel to guide trains across pointwork. The wheel is activated on pointwork and runs in a slot between the tracks.

14 of the 16 trains are needed for the peak hours each day and trains operate from 05.15 to 00.30 Monday to Saturday, 07.30–00.30 Sundays.

Signalling and communications

VAL trains are driverless and controlled automatically using a transmission-based system.

Trains are kept apart by controlling their speed as they pass over track-mounted beacons. This controls their distance from the train in front and keeps the service at its planned two-and-a-half-minute frequency.

Security is a high priority with 130 cameras patrolling stations and trains, with at least four people at a time at the central command post. Passengers can talk to control room staff using on-train help points.

The future

The metropolitan area of the city is expanding at a rate of an additional 5,000 people each year and the current service already provides transport for 55,000 people more than was originally planned. Proponents have argued for an extension to the system for many years.

In December 2007, draft plans detailing a new route were finally submitted and on 7 July 2008 the Rennes Metropole council issued a favourable recommendation towards the build of a second line. This line will link the area of Champs Blanc with the quarters of Maurepas and eventually south to the area of Morinais.

The build of Line B should begin by 2013 and is due to be finished by 2018. The mayor, Emmanuel Couet, has asked all districts to approve the draft plans before they are adopted by the Rennes Metropole council. By 2013, the council should have paid off all loans used to finance the initial construction of the first line and will once again have capacity to borrow more for the new construction.

The future Line B will have 15 stations spread over 12.7km, of which 8.5km will be deep underground. The exact financing structure is yet to be determined but it is believed at least 25% will come from the state.