28/10/00

TILTING TRAINS : HAS IT BECOME ‘IN VOGUE’ TO USE THESE OR ARE THEY A REAL NECESSITY ? THE EXPERIENCE OF SEVERAL EUROPEAN OPERATORS.

Giancarlo PIRO - ROLLING STOCK DEPARTMENT - TRENITALIA -

Abstracts:

This article deals first of all with the problem regarding the use of tilting trains, how the necessity to use this type of train arose, which problems they aim at solving, and what has up, until now, been the response of the FS to this question, with descriptions of the types of trains produced by the national Industry for the FS, together with a brief outline of their main features.

The second section poses a fundamental question, in other words, if and when a is necessary and on which types of lines and networks is its use most congenial. An analysis is then made of the features that a train of this type should have in order to meet the various requirements, with a quick look, solely from a qualitative point of view, at the costs to be sustained by a network in organising this type of operation.

Following, the types of trains available on the market are examined with a summary of the conclusions regarding the most profitable way of utilising these trains and the environments most conducive to their use.

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Before dealing with this question, it is deemed useful to give a brief outline of the history of tilting trains.

The reduction of transiting times has always been one of the main objectives of Railway Operators; the difficulties that have created obstacles in achieving this aim were represented at the beginning by the insufficient performances of the motive powers and vehicles, and afterwards by the speed limits imposed by the infrastructures on trains that in the meantime have become increasingly faster and more powerful.

In order to overcome this last limitation it was therefore necessary either to build new infrastructures or improve the existing ones in a consistent manner, both solutions being extremely costly and in many cases not justifiable in relation to the cost-benefit analyses. Nowadays – with the ever-pressing need to increase the speed of trains –there was no other solution than that of attempting to increase the speed of the vehicles operating on existing infrastructures where no radical improvements were foreseen, with only limited strengthening operations instead.

1 The idea thus eventuated of using vehicles which, while not being any more aggressive towards the track and also the power supply catenaries in the case of electric traction) than the traditional ones – would be able to circulate on bends (points where the speeds are normally more limited) at higher speeds than those foreseen for traditional vehicles. Numerous railway administrations and industries have tried to solve this problem, and the Italian solution was the first to give satisfactory results. In fact, in 1969 the Fiat Ferroviaria company created its own vehicle with a tilting body, called the Y 0268. This was subjected to a lengthy, in-depth test campaign by the FS, at the end of which positive conclusions could be drawn: the system studied satisfied the foreseen requirements and the speeds reached could in theory be up to 30% higher than those of the traditional vehicles travelling round bends with the same characteristics. Moreover, the passengers’ travelling comfort not only increased, but it was also observed that the number of passengers suffering from kinetosis decreased, and the stress on the rails was even less than that produced by traditional vehicles under the same conditions but travelling at lower speeds.

The positive conclusion of the above-mentioned cycle of tests led to the ordering of the first trainset consisting of four vehicles by the FS at the beginning of the seventies, with a similar one also being ordered by the Spanish Railways (RENFE). The FS train, called ETR 401, entered into operation in the mid seventies, however, being the only specimen (example), it hardly represented a real commercial operation, as had been expected at the beginning, when it was used on the tortuous line from to Ancona. Therefore, after the initial period, this train was withdrawn from the operation it was intended for and used exclusively for conducting tests in order to further analyse all the aspects of the tilting technique in lengthy test campaigns both in and abroad. Since then the FS has put various trains of this type, commonly called Pendolini (tilting trains), into operation, so that today its pool consists of approximately 50 trains with electric traction, fitted out with active tilting and designed for a maximum speed of 250 km/h, while further trains with diesel traction are currently being acquired.

As already mentioned, another significant feature of tilting trains is that they allow for an increase in travelling comfort on bends, due to the diminishing (if not the actual annulling) of the value of the centrifugal acceleration on passengers with an almost complete disappearance of the negative effects of the forces that normally tend to make passengers lean towards the outside of the bend they are travelling round. This positive effect is also confirmed by the fact that several networks have put tilting trains into operation with the so-called ‘passive’ type of tilting that derives solely from the fact that, as it is already going round the bend, the train tends to lean due to the centrifugal force: in this case in fact, there is hardly ever any corresponding increase in speed but simply an increase in travelling comfort.

The main characteristics of the FS tilting trains, belonging to the ETR 450, 460, 480 and 470 series (this last one in co-ownership with the Federal Swiss Railways and the Railways of the Bernese Alps) have been singled out in order for the trains themselves to perform their services at a high standard and in all cases higher than that reached up until that time on the main lines of the Italian network. In particular, the aim was to make the trains capable of profitably using the High Speed lines, like the Florence-Rome line for example, designed for a speed of 250 km/h (a speed on the other hand that is permitted for all these trains except for the ETR 470 series, as being specialised for Italian-Swiss relations it does not require speeds of more

2 than 200 km/h), in order for said trains departing from Rome to be able to make rapid connections between the Capital and the main cities in the north of the country while travelling on absolutely “normal” electrified lines where no radical operations for improving the infrastructures were or are foreseen (except for the High Speed Florence- line). Table 1 gives an indication of the main features of these trains.

In order to give an overall idea, it must be pointed out that the connections carried out by the tilting trains on the national network are integrated with European connections with , and , in the first two cases with 9 trainsets of the ETR 470 series already mentioned above, while connections with France are guaranteed by 3 trainsets of the ETR 460 series, run by the Company, a joint venture of the Italian and French Railways. There are 50 of these services offered in Italy, 12 between Italy and Switzerland/ Germany, and 4 between Italy and France, with an overall daily transiting of approximately 35,000 km.; the Cities served are just on 150, of which a hundred or so in Italy and the rest in Switzerland, Germany and France, with a number of train*km that approaches 2.5 million per day.

As has already been mentioned, the strong points of these trains are their increased travelling comfort and reduced transiting times, the latter being assessed at from 10 to 20% with regard to the previous ‘top’ times; table 2 gives a summary of all the connections carried out by tilting trains departing from Italy. It must also be pointed out that this type of train has created the possibility for medium- sized cities to be connected in a rapid and direct manner with the Capital, as well as connecting foreign cities with the main industrial poles of northern Italy. Lastly, it is interesting to note that due to these trains having an extremely reduced static axle weight (not exceeding 13.5 t/axle) with the traction motors completely supported by the body, together with a good part of the movement, the dynamic stress induced on the tracks is also extremely reduced. The most significant consequence of this features lies in the fact that no particular maintenance operations to the tracks are necessary after the running of these trains, apart from the normal maintenance foreseen for networks of a certain level. It is therefore possible to use all the electrified lines of a network like that of the FS for these tilting trains as required: for example, there are the connections from Rome to , Vicenza, and Taranto that have only recently been created, while others have been cancelled due to no longer being retained as profitable.

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At this point it is necessary to raise the question: does the tilting train really provide the solution to several important problems regarding the medium and long-journey passengers services, or has this desire to be ‘in vogue’ taken the upper hand with numerous networks adapting to fashion and choosing this type of train without previously carrying out detailed cost-benefit analyses? The answer to this question is quite complex and requires a series of considerations.

The on-line tests with the FS ETR 401 prototype train were carried out on European networks differing one from the other with regard to characteristics, but generally all

3 offering uniform levels of average to high range track maintenance: it is obvious therefore that the results obtained can be only extended to networks with the same maintenance levels and cannot be applied indiscriminately to the lines of every type of network.

For this purpose, and purely as an example, we wish to point out that the tests conducted with a DB tilting train of the VT 610 series on an SNCF line in the south of France in the summer of 1995, a line that did not present a high level of maintenance, did not and could not consequently give results in line with those indicated above; this particular line had very limited traffic and therefore was not expected to have a high maintenance level. Another aspect to keep in mind is connected to the speed increase to be carried out, something that affects not only the evident gains in terms of cutting down on transiting times, but also influences the increase in stress on the track seeing that this varies depending on squared value of speed. In this case the increase in maintenance that has to be carried out may be quite considerable and it is precisely this factor that has to be kept in mind when calculating the cost-benefit budget. Another aspect to be considered is the increase in the amount of traffic to be developed on the line in question: in other words it is important to keep in mind whether the line is a simple or double track, the train spacing systems used, and the quantity of traditional traffic already present on the line before introducing the tilting trains, etc.

If in fact a simple track line is considered it will be necessary to take into account all the inevitable time losses in carrying out the crossings, something that limits the advantages of using tilting trains in a more or less sensitive manner, depending on the consistency of the traffic. Another aspect to keep in mind is related to the type of train spacing and signalling present on the line in question; in fact, on the traditional lines of the various networks the signalling systems normally allow for maximum speeds of 160 km/h; for higher speeds it is therefore necessary to integrate the system in such a way as to allow for speed control (if not already existing) amongst other things. It is evident that if the line allows for maximum speeds of around 160 km/h, the tilting trains would be able to circulate at higher speeds than the indicated limit and therefore necessitating additions to the signalling, despite the fact that the percentage of trains requiring said additions would be limited and the relative investments could be out of proportion with the advantages obtainable. The third aspect to take into account concerns the density of traffic; in fact, even with the types of signalling offering higher performances, the trains cannot follow each other at time distances that are lower than a certain limit dictated by the capacity of the line; it is obvious therefore, that a train with a time schedule with speeds higher than those of the trains preceding or immediately following it would enter into conflict with these other trains. The greater the speed difference between the types of trains in question, the greater the probability of conflict, something that could interfere with the timetables of the two different types of train causing inevitable delays as a result.

Up until now numerous networks have chosen to make use of the tilting trains for the most varied types of passenger services, from the top-of-the-range ones like the IC and EC trains, or the night trains (where the simple increase in travelling comfort is anything but of secondary importance), to even the regional and interregional trains.

4 In fact, as far as night trains are concerned, the Spanish railway industry has manufactured the TALGO trains that are most suitable for this type of service (even though not limited just to this service) and use a “passive” tilting system: in this case there is not actually an increase in the speed with respect to traditional trains, but only a considerable improvement in travelling comfort, something that certainly cannot be overlooked on night trains. The Talgo trains currently carry out day time connections between the main Spanish cities and night time connections between Spain and several European cities, as this system has independent wheels instead of axles, allowing for the adopting of a rather simple system of variation between the Iberian gauge to the European one. The Talgo rolling stock is also used for carrying out internal night time connections with Germany, where these trains travel under the trade-name of ICN (Inter City Night).

Instead the so-called "active" tilting systems require far more sophisticated and costly equipment, however they are in a condition to act in real time and with tilting angles that can reach up to 10 degrees, meaning that they can allow for considerable speed increases and at the same time carry out on-the-spot adaptations of the vehicle tilting at every point of the bend. To be noted amongst these systems, the Adtranz system, used for top-of-the-range trains in Sweden (X2000 trains) and Norway for connections between Oslo and its new Gardemoen Airport. The X 2000 trains have allowed for achieving marked reductions in travelling times (up to 20%) in the connections between the main cities in Sweden. In Germany the tilting train service began at the end of the eighties with regional services in Bavaria, thanks to diesel traction trainsets called VT 610 fitted with the Italian tilting system. These trains, consisting of two vehicles with 120 seats, can travel at a maximum speed of 160 km/h, with an installed power of 1200 kW, and connect Nuremberg with the main cities of Franconia (Northern Bavaria), in correspondence with the IC – ICE services. More recently the ADtranz company has manufactured another tilting diesel train (with hydraulic transmission in this case), with features similar to those of the train mentioned above and called VT 611 that is always used for regional services in the Renania- Palatinato Region. Only recently in Germany it has been retained useful to use tilting trains also for the High Speed services as in Italy; the trains in question are called ICT, with both electric and diesel traction, allowing for speeds exceeding 200 km/h in both versions, and offering extremely elevated output.

In the USA also, High Speed tilting trains, called ACELA, have recently entered into operation for carrying out services in the North-east corridor between Boston and Baltimore, via New York, Philadelphia and Washington. The manufacturer of these trainsets is Bombardier, who decided to experiment its own tilting system on these trains that was already in use about twenty years ago on top- range Canadian trains called LRC (Léger, Rapide, Confortable).

Apart from the above-mentioned cases in Italy and Germany, the Italian tilting system is already in operation in various other European countries, or is about to be put into operation in the very near future. In fact, the Finnish Railways (VR) have top-range trains in operation called S 220, consisting of 6 vehicles, with 25 kV electric traction, that carry out rapid services between Helsinki and Turku, the embarkation port for the ferries to Sweden.

5 An extension of the services involving these trains is also foreseen in the very near future as far as Russia, and more precisely to Saint Petersburg, in which case however, the trains will have to be 3 - 25 kV bi-tension in order to be compliant with the voltage used in the Russian city.

The private English Operator Virgin has recently ordered from a Consortium including Fiat Ferroviaria, 50 tilting trains with a speed of 250 km/h, consisting of 7 vehicles, with electric traction, to be used in the connections between London and Scotland, via the line it manages, the West Coast Main Line.

Other projects that are currently underway with the tilting trains supplied with the Italian system of tilting body include (apart from those in Spain and Portugal already in existence and mentioned above), the one for the Czech Railways with three-tension tilting trains for carrying out connections between Berlin, Prague and Vienna, and the Malaysian one for connections between Singapore and the main cities of the Malaysian Federation. ------

From the above considerations and the examples illustrated, in summing up it can be stated that the rational and profitable use of tilting trains will depend on a number of factors that have to be carefully considered before making any decisions along these lines. What is certain is that the most advantageous use of these trains can be made on the most highly evolved networks where this type of train is capable of representing a valid and economical means of increasing both the potential of the lines and the railway travel attraction for the clientele. In final analysis, they also offer an improvement in passenger service, limiting to a maximum the investments involved in improving and strengthening the infrastructures, especially in the case in which the speeds of the various trains already running on the lines in question do not present any relevant differences compared with the speeds of the tilting trains, and where the traffic density is not nearing saturation point.

Furthermore, the use of tilting trains could also be proposed for the most varied types of services, from top-of-the-range to regional and interregional services, obviously without excluding the night time connections, for which it will be possible to obtain not only reductions in transiting times but also greater advantages from the point of view of passenger comfort, without the need for any significant modifications to the infrastructures and just a moderate increase in the life-cycle costs of the rolling stock.

6 TABLE No.1: Main Characteristics of the Italian tilting trains of the ETR 450, 460, 470, 480 series.

MAIN FEATURES OF THE TILTING-BODY TRAINS

OF THE SERIES 450, 460, 470, 480

ETR 450 460/480 470 Forming 8 M + 1 T 6M + 3 T 6 M + 3T Quantity 15 23 9 Length 234 237 237 (m) Weight (tons) 435 433 440

Tractive power distributed distributed distribute d Feeding Voltage 3 kVdc 3 kVdc 3 kVdc - 15 kVac 1,5kVdc(*) 25kVac(*) Output (kW) 5100 6000 6000

Top speed (Km/h) 250 250 200

Max. tilt 8^ 8^ 8^ Electrical chopper inverter inverter Equipment Axleload (tons) 12,5 13 13,5 Seats 390 458 460 Main features Air conditioning Air conditioning Air conditioning

Restaurant and bar Restaurant and bar Music at seat Restaurant and bar Air tightness Music at seat Air tightness (*) only in part of the above mentioned trains.

7 TABLE No. 2: Connections with tilting trains between ITALY and neighbouring countries.

CONNECTIONS CARRIED OUT WITH TILTING-BODY TRAINS IN ITALY AND NEIGHBORING COUNTRIES

Connection Quantity Distance Running time Commercial Best time Improvement (pairs of (Km) speed with IC (%) trains) (km/h) trains Savona – Roma 1 605 4H55’ 123 5H48’ 15% Spezia - Roma 1 411 3H38’ 112 3H54’ 7% Torino - Roma 3 725(1) 5H35’ 130 6H45’ 18% Milano - Ancona 1 423 3H55’ 108 4H17’ 9% Bergamo - Roma 1 660 5H20’ 124 6H40’ 20% Vicenza - Roma 1 600 4H52’ 128 5H10’ 6% Venezia – Roma 3 573 4H30’ 127 5H12’ 13% Perugia - Roma 2 205 2H07’ 97 2H30’ 16% Ancona - Roma 3 215 3H08’ 101 3H30’ 11% Roma - Bari(2) 4 495 4H25’ 112 5H56’ 15% Roma - Reggio C. 2 675 6H00’ 112 6H40’ 10% Roma - Taranto 1 477 5H00’ 93 5H40’ 12% Roma - Potenza 1 326 4H00’ 81 4H35’ 11% Roma - Bolzano 1 674 5H35’ 121 6H37’ 16% Milano - TO - Lione 3 3H49’(3) 4H20’ 12% Milano - Ginevra 2 3H36’ 4H52’ 25% Milano – Zurigo 3 3H38’ 4H09’ 14% (Stoccarda) Milano – Berna 1 3H11’ 3H58’ 19% (Basilea)

1. The distance indicated refers to the itinerary via Pisa - Florence - Rome

1. One of such connections extends as far as Lecce

1. The time indicated is that of the Torino - Lione connection.

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