A historical evolution of the light rail concept

The history of light railcars

Admittedly, railcars of this type are currently being built by the Compagnie des Chemins de fer départementaux (C.F.D.) but only for the last metric track networks in France (Chemins de Fer Corses, Chemin de Fer de la Provence, Réseau du Blanc-Argent) which are not necessarily the best testing grounds, and nothing was planned on the SNCF.

Historically, light railcars of all gauges had indeed existed and they had contributed on many departmental networks to contain the unbridled road competition of the 30's. There were even several generations of rail coaches such as the "Floirat" coaches, the "Verney" coaches, the "Talon" system coaches ... which made it possible, during the German occupation, to make up for the lack of tyres or to compensate for the lack of railcars at the time of the Liberation. Several lines were operated for many years by Floirat coaches (Capdenac-Cahors-Monsempron-Libos-Agen...) and Verney coaches remained until the end of passenger service in 1965 on the important standard gauge network of the Chemin de Fer de Mamers-St-Calais.

The only "light", purely railway and truly modern, unified series machines built for the S.N.C.F. and operated by it in the years 1945-1955 were the F.N.C. railcars with axles. of 90 horses, designed under the aegis of the Fédération Nationale des Cheminots, and the Renault of 150 horses, series X 5500 and X 5800, with carriages of 2 axles each (thus 4 axles in all), which are nowadays all decommissioned from passenger service on the national network. The remaining X 3800s, known as the "Picasso", although they have a reduced capacity (62 seats, 2nd class), cannot, given their 300 horsepower, be described as "light".

Truly "light" railcars ran on the leased S.N.C.F. lines, whether under C.F.T.A. administration. (Provins network) or under that of the C.F.D. (Autun network). In both cases it was a question of "Billards" railcars, from the well-known Tourangeau manufacturer, who did so much for the modernization, alas too late, of most of the French secondary networks.

It can be noted that examples of all the above-mentioned machines can still be seen on many tourist networks which have preserved them. For example, an F.N.C. in good condition is kept at the Richelieu depot (Trains à Vapeur de Touraine and Régie Ferrée Richelaise), while two machines transformed into driving cars continue to provide service on the national network, two "Verney coaches" are at the Connerré-Baillé depot managed by Transvap (Connerré-Bonnetable line), and two billiard railcars are used as driving cars on the lines leased to the C.F.D. around Autun, while a similar device, the 9132, plays a very active role in the tourist passenger service of the Chemin de Fer Touristique de la Vallée de la Doller (Cernay-Sentheim line).

This list is not exhaustive, and many other old series railcars saved from the scrap metal, and that can be described as "light" continue to run here and there in France, whether on the tourist metric networks of the Baie de Somme (Cayeux-Noyelles-Le Crotoy line) and the Vivarais (Bas et Haut-Vivarais), or on the normal gauge lines of the Doller and Labouheyre-Sabres where venerable Dion trains run. As for the 150 horses, several of them are present on the Doller, Sabres, Bréda (Pontcharra-la-Rochette line), Grasse (Comité Cannes-Grasse) or Hyères.

Light railcars abroad

Light" railcars have sprung up all over the world, in Italy, Sweden, Germany, Czechoslovakia to name but a few countries. It is in Germany, it seems, that lightness has been put to best use, with the operation of a large number of branch lines using the famous "Schienenbus". In Czechoslovakia, the STUDENKA workshops in the TATRAS were able to offer in 1980 17-ton axle-mounted machines with a power of 210 HP capable of towing one or two trailers.

The policy of abandonment

For about thirty years, no new standard gauge light railcar had been experimented on the S.N.C.F., mainly because of the policy of progressive abandonment of the great majority of the omnibus links, leading to the disappearance of a large number of secondary lines. As the reasons put forward by the S.N.C.F. were financial, as these services were considered to be very loss-making, it appeared to many observers, whether transport specialists, representatives of local authorities or users, that if the deficit was to be tackled, it was necessary first of all to try to obtain savings on equipment and to revert to machines better suited to the diffuse and weak traffic that needed to be resuscitated. The 425-horsepower "Caravelles" and the 600-horsepower X-2100s, the foundations of the modern N.C.S.F. fleet, were clearly overpowered to serve the small lines to be maintained or reopened.

Given that railway technology has considerable advantages over road technology (safety, regularity, comfort, energy saving) even in omnibus service, it was necessary to study the possibility of influencing the various factors which make rail more expensive, namely :

• the return to "light" machines, which would generate savings during the construction and operation of secondary lines for which they would be specially designed.
• a redefinition of the operating methods of secondary lines
• a reassessment of the criteria for recognizing passenger omnibus service expenses; and
• All of this, of course, depends ultimately on a re-estimation of the cost of railways on a nationwide scale, integrating certain social costs for the community, to be defined within all modes of transport.

This approach seems to have been followed abroad as well. For example, some manufacturers have been considering a return to rail coaches, such as British-Leyland, which has designed a railcar that is in fact only a juxtaposition of two halves of coaches, which was tested in 1980. A technique that has also been tested in Canada and Australia.

In France, this technique was rejected by the S.N.C.F. and the manufacturers had to comply with the usual safety standards.

The originality and the interest of the symposium was that the aim moved from its opening: there was no need to make the builders aware, since they were already aware and they came, for three of them, with very elaborate projects in their boxes, so that, in the presence of representatives of the S.N.C.F., the Ministry, elected representatives and users, it was possible to move on to the next stage and proceed to the detailed presentation of the projects, with a wide debate on their respective interests.

The manufacturers' proposals in the order in which they were presented at the conference

If the C.F.D. can present a large choice of engines, in a wide range of prices, it is because they benefit from the experience acquired as the only current manufacturers of light railcars (Provence and Corsica). Participants in the symposium were able to make a demonstration trip between Nice and Villars-sur-Var on the morning of March 30.

Alsthom has designed a more traditional machine, adaptable in 3 versions, which its 32-tonne mass places at the limit of lightness, but we saw that this criterion was not directly linked to economics, which is ultimately the ultimate objective sought.

As for SOULÉ, his "T.F.E.S.E." project.. (Transport ferroviaire économique Soulé - Enertrans) was noticed for two reasons:

• on the one hand, it adopts an axle version, which is a return to a technology that has been abandoned for 30 years, at least in France. This manufacturer ensures that original suspension systems will allow a good quality of comfort. In exchange, it undeniably gains in lightness by freeing itself from the rubbers since, even with a mass of 16 tons, the shunting of the track circuits is ensured.
• on the other hand, in association with the promoter ENERTRANS, it goes beyond the simple construction of a railcar to propose, around its machine, a new mode of operation of secondary lines: the T.F.E.S.E.

Bernard POIRREZ, commissioned by EXPO- RAIL to organise and lead the symposium, was responsible for demonstrating, with examples and F.C. 12 J in hand, that the profitability of S.N.C.F. omnibus links. especially when they constituted the totality of the traffic of a given line, went well beyond the problem of the lightness of the equipment and had to be accompanied, above all, by a redefinition of the criteria for accounting for loads, and even by a downward revision of the standards of maintenance of the secondary railways, taking into account the axle weight limitations of the machines called upon to operate on them, and the relatively low speeds practised. Nothing can be saved from the omnibus network if the current standards, which are too pejorative for this traffic, are maintained.

The present file constitutes the official report of the colloquium. However, the file on light rail transit is not closed for all that. It is to be hoped that the manufacturers will obtain the necessary credits for the construction of prototypes and that experiments will be carried out on real sites. The organisers, for their part, will continue to provide assistance in any useful follow-up to the important issue of "light rail".

source : L'autorail léger, Proceedings of the 1982 Exporail Symposium, by Gérard ROBERT