Over the past 15 years Paris has opened four orbital light rail lines, providing links between the city's radial metro and RER corridors. But the four routes exhibit a high degree of technical incompatibility, reports Harry Hondius

Paris tram route T3.

IN MORE and more cities, the traditional flows of commuters in and out of the centres are being replaced or augmented by significant movements between suburbs, for both work and leisure purposes. This reshaping of demand can pose major challenges to the public transport operators, particularly where orbital flows are not aligned with existing high-capacity corridors.

The local authorities in Paris were amongst the first in Europe to identify this trend in their long-term planning, leading to the development of orbital light rail and tram routes connecting the radial rail and metro corridors.

In the 15 years since the first modern tram route was opened in the Ile-de-France, four lines have been constructed, and several extensions are underway or planned. Today there are 97 vehicles operating on 39·2 route-km, but within five years the totals could reach 144 cars and 68·5 route-km.

Of course this is a far cry from the city's historic tram operation, which was one of the largest in the world. In 1928 more than 3 000 trams and trailers carried 727 million passengers/year on a 725 km network, but the whole lot was swept away in 1931-38.

Pioneering on T1

Trams returned to the French capital in 1992 with the opening of the 9 km Line T1 connecting RER Line D at Gare St-Denis and metro Line 13 at Basilique de St-Denis with Line 7 at La Courneuve and Line 5 at Bobigny-Pablo Picasso. Seven years later, work began on a 3 km extension from Bobigny to meet RER Line E at Noisy-le-Sec, which finally opened in December 2003.

The T1 fleet shares the Line 5 depot at Bobigny, but like routes T2 and T3 it is operated by RATP's bus division rather than the metro. Today T1 is the operator's busiest surface route, handling 28 million passengers in 2005, or an average of nearly 79 000 per day. Trams cover the 12 km in 44 to 47 min at a commercial speed of around 16 km/h.

Running though a densely populated area, T1 services operate every 4 to 5 min. Load factors are high, and there is a steady turnover of passengers making short journeys. Most of the route is on a segregated alignment, but there are many intersections with road traffic, which is extremely heavy. Whilst the line does have priority at junctions, it seems that trams almost always have to stop before getting a proceed aspect.

The original track quality was poor, and started to deteriorate very quickly, leading to corrugations that were gradually ground out from 1998 onwards.

The fleet was very tight at first, with only 16 TFS2 part-low-floor cars, but an extra three were added after 1996. Further relief came in 2002 when the 16 similar cars displaced from T2 were transferred to T1 to cover the extension to Noisy-le-Sec. The early shortage of cars was reflected in a lack of maintenance, and the cars became very noisy, but changes to the maintenance regime have solved this and the trams run very smoothly and relatively silently. There is a slight squeak from the articulations, and a steady noise from the GTO choppers.

RATP is currently planning two extensions at both ends of T1. At the western end, construction work will soon start on a 4·8 km extension from St-Denis to meet Line 13 at Asnières-Gennevilliers III, which is expected to open at the end of 2008.

The eastern extension would initially run for 5 km from Noisy-le-Sec to Montreuil-Théophile Sueur, adding a further 11 stops. This is costed at €140m, and is expected to open in 2012 — squeezing a suitable alignment through Noisy-le-Sec is the primary reason for the delayed schedule.

In the longer term, another 3 km from Montreuil would take T1 to Val-de-Fontenay, making the line 25 km long, as part of a proposed tram circle around Paris. Fontenay – Gennevilliers is expected to take 87 min, at 17·2 km/h, slightly faster than today. Serving 200?000 inhabitants and 67?000 workplaces, the lengthened route is projected to carry 178?000 passengers per day, which would be very high indeed by European standards.

Along the Val-de-Seine

A second tram route followed in 1997, with the opening of Line T2 between Issy-Plaine and La Défense. This follows the alignment of the former orbital railway from Invalides to Saint-Lazare along the Seine river through Puteaux, opened in 1889. Electrified with 750 V DC, third rail in 1928, it remained a technical outpost after the rest of the Saint-Lazare network was converted to 25 kV 50 Hz.

Latterly worked by 1·5 kV DC EMUs running on half-power, the railway was finally closed on May 2 1993, a year after freight trains ceased serving the Renault plant at Billancourt, itself since closed. After dismissing plans to make the route a branch of RER Line C, SNCF and RATP agreed to convert it to light rail, with a northern extension to La Défense.

After 4½ years of substitute bus services, T2 opened on September 2 1997. The cost of converting the 11·3 km line was put at €136m, including 16 TFS2 cars. The basic service runs at 10 min headways, covering the route in 22 min with 12 stops at an average of 30·8 km/h, demonstrating the benefits of a fully-segregated railway alignment.

In September 2005 the T2 fleet was replaced by Citadis 302 low-floor cars, which operate in pairs at a maximum of 70 km/h, reduced to 60 km/h in tunnels and 20 km/h over a few pedestrian crossings. The stops had to be lengthened for multiple operation, at a cost of €15m, or €625?000 per platform. Built for an end loading of 400 kN, the Citadis cars run on refurbished railway track, which is very noticeable. Citadis 302 cars tend to gallop and roll, and the lack of primary suspension on the Arpège bogies is particularly apparent on pointwork and crossings.

At Issy Val-de-Seine passengers transferring to the RER are faced with a steep — and uncovered — climb to the Line C platforms. Nevertheless, T2 is now carrying 65?000 passengers per day, or 19·2 million per year, which is far more than the original expectations.

T2 is also being extended at both ends. First will come a 2·3 km extension from Issy Val-de-Seine to Porte de Versailles, due to open in July 2009, at a cost of €72·5m. Running on a separate track parallel to the Boulevard Périphérique, this will add three stops: Porte de Sèvres, with an interchange to Line 8, Porte d'Issy and Porte de Versailles, where it will meet Line 12 and T3. Journey time will be increased by 8 min.

A 4·2 km northern extension from La Défense to Bezons via Courbevoie, La Garenne and Colombes is expected to open in the summer of 2011, adding a further seven stops. This line will be built in the middle of RN 192, which will be transformed from a four-lane road into a local boulevard with trees and cycle paths. These urban landscape works have helped to push up the estimated cost to €233m, or €55·4m/km, compared to just €11·6m/km for the original conversion. To operate the new extensions, RATP has exercised an option with Alstom for a further 34 Citadis 302 cars.

Boulevards des Maréchaux

The city's newest tram route, T3, is also the first to operate inside the historic city walls. Today this ring is marked by the disused alignment of the Petite Ceinture ring railway, closed in 1934, the Boulevards des Maréchaux ring road, and the six-lane Boulevard Périphérique urban motorway built in the 1960s and 1970s.

The Périphérique is now overloaded for much of the day with more than 13 000 cars/h. This in turn put pressure on the Boulevards des Maréchaux which carry upwards of 3 000 vehicles per hour.

As described in RG 4.06 p200, T3 was intended to reclaim the southern part of the Boulevards des Maréchaux as a green corridor, linking six metro and 12 bus routes plus RER Line B. Around 80% of the 7·9 km route is laid on a grassed reservation, although the line is laid with grooved rail throughout and provided with a weight-tensioned twin-wire catenary. To make way for the 6 m wide reservation, the road space has been reduced from three lanes of 3 m to two of 2·8 m in each direction. Total cost of the project — including the urban renewal works- was €312m, or €39·4m/km.

To operate T3, RATP ordered a build of 43 m long Citadis 402 cars, which are 2?650 mm wide, in contrast to the 2?400 mm width of the earlier vehicles. They are without doubt impressive trams, and with three of the four trucks powered by six 120 kW motors they have excellent acceleration.

Herein lies the greatest disadvantage for T3. The line has to cope with 38 traffic light crossings, where the speed is limited to 30 km/h, and the priority system nearly always forces the trams to stop. The former underpass at Porte d'Italie has been abolished to create room for a tram-bus interchange on the town side.

Top speed at present is 50 km/h. It is difficult to understand why RATP does not exploit the potential of these cars by letting them run at up to, say, 65 km/h. The track quality is perfect and the Arpège trucks ride very well.

At present the end-to-end journey time is 26 min, and the commercial speed 18·2 km/h, although RATP would like to achieve 20 km/h. Acceptance of the new line has been rapid, and usage is high. Whereas the overloaded PC1 bus route transported 55 000 passengers a day, RATP reports that T3 is now achieving 80 000 to 100 000 on weekdays and 70 000 at weekends. Services operate every 7 or 8 min off-peak, and at 5 min intervals during the rush hours, requiring 15 of the 21 cars in daily operation.

As elsewhere in France the tram entrances offer level boarding, with a maximum 50 mm gap between platform and vehicle. T3 is really a designer tramway; designers developed the catenary masts, fixings and stops to suit their ideas. The lighting of the stops can even vary in colour depending on the time of the year and the Parisian mood!

The PC orbital bus routes serving the rest of the ring now terminate at interchanges at each end of T3, but discussions are already underway for further tramway extensions. The city would like to continue T3 from Porte d'Ivry to Porte de la Chapelle, adding approximately 13 km and 22 to 26 stops.

The estimated cost of this extension is €605m, or €46·5m/km. This is a substantial sum, and it will not be easy to find now that the French government has stopped subsidising the construction of new tram routes. Another problem is that the planners would like to close the underpass at Porte de Charenton, but the mayor is vehemently opposed to this idea.

To the west, a 1·5 km extension across the Seine would bring T3 to Porte d'Auteuil.

Train to tram in the suburbs

Opened on November 19 2006, Line T4 is totally different to the other three lines. Like T2 it is a railway conversion, but T4 is still operated by SNCF using tram-train vehicles.

Opened in 1875 and later electrified at 25 kV 50 Hz, the Ligne des Coquetiers connected Aulnay-sous-Bois on the main line from Gare du Nord to Soissons with Bondy on the Gare de l'Est – Strasbourg route. Today these stations are served by RER Lines B and E respectively. With eight stations and 11 level crossings, the 8 km branch serves an area with 280?000 inhabitants and 90?000 workplaces.

Until the 1990s, the line was served by an 8-car push-pull train running through from Gare de l'Est to Aulnay every 30 min, carrying an average of 16?500 passengers on a working day. Construction work on Line E saw the through services withdrawn in 1995, replaced by a 4-car push-pull shuttle, running every 15 min on the double track between Bondy and Gargan and every half-hour on the single-track section between Gargan and Aulnay. This led to a severe loss of passengers, falling to 10 000/day in 2000.

It was therefore decided to convert the railway into a tram line which would no longer accept UIC vehicles. Substitute bus services replaced trains from December 2003, leading to a further loss of passengers. Total cost of the reconstruction was €121m or ?€15·1m/km, including €68m for the fleet of 15 Siemens Avanto LRVs.

With the exception of Gargan, where the control centre is located, all stations were replaced by 75 m long tram stops. Three extra stops were also built. The existing track was rehabilitated, and the 25 kV overhead wiring remained in place. A new terminal platform was built at Bondy, but with no shelter. The viaduct connection to the main line is no longer used in daily operation.

Aulnay – Gargan was double-tracked, the automatic barriers were removed, and the level crossings became normal road crossings protected by signs. A new bridge was built over the Canal de l'Ourcq and the viaduct over the RN3 in Gargan adapted for double track. The railway signals were replaced by road signals, operated by the trams.

The trams are equipped with GSM-R, but otherwise operation is on sight. This means a speed limit of 50 km/h, reducing to 30 km/h when approaching the level crossings. On the two 1·5 km long stretches at each end, where there are no crossings, 70 km/h is permitted.

The Siemens Avanto cars were described in RG 6.05 p317. They are equipped with KVB automatic train protection, and are allowed to run at 100 km/h on the main line tracks between Bondy and the RER depot at Noisy-le-Sec, where three tracks have been allocated to maintain the 15 vehicles.

During daytime the trams run every 6 min, or every 9 min at weekends. The 62 tonne Avantos run very smoothly at the relatively low speeds, and are quite silent. The arrangements at the level crossings, especially the three-track crossing combined with a roundabout in Gargan, are very unusual, and there have been many minor collisions with road vehicles, although fortunately the Avantos have so far only sustained light damage.

Nine cars are used each day, covering an average of 5?000 km/month. End-to-end running time is 19 min, at a commercial speed of 25·2 km/h. SNCF has allocated 100 people to run T4, including 60 drivers — 17 for the operation and the control centre and 23 for ticket sales and revenue protection. It is expected to carry 35?000 passengers per day, but SNCF has not yet released any traffic figures.

Studies are underway to extend T4 to Noisy-le-Sec, where it would connect with T1, but no timetable for this has been announced. Meanwhile, firmer plans exist for a branch from Gargan to Montfermeil.

Although the Avanto cars are called tram-train vehicles by SNCF, T4 is really a 25 kV light rail line, and the cars only run as a train when moving empty to and from the depot. The Montfermeil extension would be wired at 750 V DC, which would make T4 a dual-system light rail operation.

It is interesting to note that Montfermeil was once served by tram route 112 from Le Raincy, one station beyond Bondy, from where you could travel 14·9 km to the tram hub at Opéra using route 21A. In fact, route 112 was the last Paris tram line to close on August 14 1938.

Four routes compared

Although they are technically different, routes T1, T2 and T3 are all successful as a mode of transport. Indeed, looking at the passenger numbers all three routes can be judged a roaring success. It is a shame that SNCF has not yet released any figures for T4.

In design terms, T1 is something of a minimalist tramway, whereas T3 has maximum design input. Being conversions of existing railways, T2 and T4 have a somewhat utilitarian feel. The design input is reflected in the cost per km, where T3 worked out at between three and four times more than the original route. Nevertheless, the controversial total remodelling of the Boulevards des Maréchaux seems to have been very well received.

Given that so much money has been spent on T3, would it not have been wiser to give the tram greater segregation at the major crossings using underpasses or flyovers and elevated or underground stops where appropriate? This would make the tram less susceptible to interference from other traffic, increase its commercial speed and enhance the safety of boarding passengers.

Line T1 and T3 are laid with grooved rails throughout, even on the 80% of T3 which is laid on grass reservation. Surely conventional flat-bottomed rails would have been less costly and more practical? Even where it is technically possible, buses or taxis are generally not allowed to share the tram tracks.

The highway authorities seem to regard modern trams as trains and have imposed many speed restrictions, especially at road junctions and level crossings. These have a severe impact on the commercial speeds, and the dynamic potential of the modern tram cars is not being fully exploited even on segregated sections.

Overall, the re-introduction of trams in the Paris region seems to have been done in a rather ad hoc manner, with no systematic planning. It was certainly logical to start in 1992 with TFS2, which was the only car type then being produced in France. This may still have been appropriate for T2, even though that had been a conventional railway.

But when T2 received new rolling stock, it was very illogical not to switch to 2?650 mm wide cars, which were by then becoming standard for new lines elsewhere. The T2 depot at Issy Val-de-Seine is within sight of Lucotte depot on T3. After the extension opens, T2 will almost pass Lucotte en route to the interchange at Porte de Versailles. Yet the difference in car width will make it impossible for the Citadis 402s to run on T2. And the narrow T2 cars would not suit the platforms on T3. No-one seems to have thought about a proper connection between T2 and T3 for the longer term.

  • CAPTION: At Issy Val-de-Seine, interchange is available between T2 and RER Line C
  • CAPTION: T1 is RATP's most heavily-used surface route. The terminus at Noisy-le-Sec may eventually offer an interchange with SNCF's T4 service to Aulnay
  • CAPTION: Porte d'Ivry stop highlights the level boarding between tram and platform on Line T3
  • CAPTION: T3 could yet be extended beyond Porte d'Ivry towards Porte de la Chapelle. This is Boulevard Masséna looking towards Porte de Vitry showing the bus lanes used by the Petite Ceinture services
  • CAPTION: As well as extensions to the existing four light rail lines now under construction or planned, Paris is looking at a number of other possible routes. However on September 13, the Ile-de-France région voted to build the 6·6 km Saint-Denis – Sarcelles route as a 'rubber-tyred tramway' at a cost of €163·1m, and this technology is also favoured for the 14 km Châtillon – Viroflay route
  • CAPTION: The road crossing at Gargan on T4 is situated across a roundabout, but it is not protected by the signalling system
  • CAPTION: As at Aulnay, the terminus of T4 at Bondy offers little shelter for waiting passengers. The connection to the main line towards Paris Est can be seen in the background

Table I. Comparison of rolling stock used on Paris tram routes

Line T1 T2 T3 T4
Car Type TFS2 Citadis 302 Citadis 402 Avanto
Supplier Alstom Alstom Alstom Siemens
Number of cars 35 26+34 order 21 15
Car numbers 101-119
401-426 301-321 TT1 –TT15
Delivered 1992-96 2002-04 2005-06 2005-06
Power supply 750 V DC 750 V DC 750 V DC 25 kV, 50 Hz*
Length m 29·4 32·9 43·7 36·7
Width mm 2 300 2 400 2 650 2 650
Weight tonnes 43·9 40·25 54·6 62·0
kg/m² 649 510 472 638
Axles B' 2 B' Bo 2 Bo Bo Bo 2 Bo Bo' 2 2 Bo'
Wheel diameter mm 660 590 590 660
Floor height mm 875/345 350 350 381
Traction motors kW 2 x 275 4 x 120 6 x 1204 x 200
kW/t 12·5 11·9 13·2 12·9
Maximum speed km/h 70 70 70 100
Multiple operation No Yes No Yes
Seats 54 58 76 80
Standees @4/m² 120165 226 162

* Also suitable for 750 V DC

Les projets parisiens prospèrent en dépit de leur diversité

Au cours des 15 années écoulées, quatre projets de ligne de tramway tangentielles ont vu le jour à Paris, créant des liaisons entre les lignes radiales de métro et les axes de RER de la ville. Mais, selon Harry Hondius, ces quatre lignes affichent un haut degré d'incompatibilité technique entre elles. Les lignes T1 et T3 sont des tramways roulant sur la chaussée tandis que les lignes T2 et T4 sont des lignes de chemin de fer reconverties. Des prolongements sont déjà en construction à la fois pour les lignes T1 et T2, d'autres sont prévus et des pourparlers sont en cours pour un allongement substantiel qui mènerait la ligne T3 autour du flanc est de la ville. Une branche de la T4 est également envisagée afin de desservir Montfermeil

Pariser Projekte erfolgreich trotz Vielfalt

In den letzten 15 Jahren wurden in Paris vier peripher gelegene Stadtbahnstrecken eröffnet, welche die radial ausgerichteten Metro- und RER-Korridore miteinander verknüpfen. Aber die vier Strecken zeigen einen hohen Grad an technischer Inkompatibilität, berichtet Harry Hondius. Die Linien T1 und T3 sind eigentliche Strassenbahnen, währenddem T2 und T4 umgerüstete Bahnstrecken sind. Erweiterungen sind bei T1 und T2 im Gang, und weitere Ausbauten sind in Planung. Diskussionen laufen zudem über eine lange Erweiterung, welche T3 um den Ostrand der Stadt herumführen würde. Ein Zweigstrecke der T4 soll zudem Montfermeil bediene

Los proyectos parisinos prosperan pese a su diversidad

En los últimos 15 años, se han inaugurado cuatro líneas de tranvía orbitales en Paris que proporcionan conexiones entre las líneas radiales de metro y RER de la ciudad. Sin embargo, estas cuatro rutas muestran un alto grado de incompatibilidad técnica, según informa Harry Hondius. Las líneas T1 y T3 son tranvías que circulan por la calle, mientras que las T2 y T4 son líneas de ferrocarril reconvertidas. Las prolongaciones de las líneas T1 y T2 ya están en construcción, pero todavía se planean más ampliaciones. Mientras tanto, hay en marcha gestiones para una gran extensión de la T3 en el lado este de la ciudad. También está prevista la construcción de un tramo de la T4 que dará servicio a Montfermeil