INTRO: With nearly 50 years of operating experience, Patentes Talgo is now developing the Talgo XXI trainset, featuring diesel or electric power cars with gauge-changing capability. The latest Series 7 cars will also form the basis of a high-speed train aimed at the Spanish market

BYLINE: Francisco de Lorenzo

Chief Executive Officer

Patentes Talgo SA

On trial in Spain is a 220 km/h prototype trainset with integral power cars. It is the forerunner of an electrically-powered derivative with a design speed of well over 300 km/h. These innovative trains apply the main principles which were developed almost half a century ago, when the first generation of Talgo trains entered commercial service in July 1950 between Madrid and Irún on the French border. With their serpent-like appearance and striking diesel power cars, the Talgo II trains were something of a railway milestone, both in terms of the novel technology they introduced and the superior travelling environment they offered.

These pioneering trains were followed over the next 50 years by successive generations of Talgo III, Talgo RD and Talgo Pendular trains, each introducing refinements to the concept. In many instances Talgo has pioneered innovative solutions to practical operating problems that have gone on to become standard for modern passenger rolling stock.

In 1964 the Talgo III introduced the simple and effective wheel-steering system applied to all subsequent builds. This keeps each wheel parallel to the rail, reducing wheel and rail wear and improving safety. Unlike its predecessor, the Talgo III could be hauled in either direction without the need for turning, and the power car permanently coupled to each Talgo II was replaced by a conventional locomotive.

To haul its Talgo III trainsets, Spanish National Railways (Renfe) ordered 10 Class 352 diesel-hydraulic locomotives from Krauss-Maffei. These small-profile single-cab locomotives are still in service today, equipped with a diesel generator to supply the trains with electricity for heating and lighting. For its variable-gauge Talgo RD trainsets and the Talgo Pendular with passive tilt, Renfe acquired the Class 353 and 354 diesel locomotives, designed to match the coaches both in terms of proportion and styling. These locos have been maintained by Talgo since their introduction, and some of them have now run over seven million km in revenue-earning service.

The Talgo Pendular was also designed to be hauled by conventional locomotives, which in addition to providing greater operational flexibility and allowing more intensive use, has led to its use with diesel and electric traction in Europe and the USA. The Talgo RD has also tended to be hauled by conventional locomotives, as its gauge-changing technology has not as yet been applied to powered axles.

Back to the future

In recent years we have noticed a clear trend towards shorter trainsets for inter-city applications, each with their own traction equipment and a cab at both ends for operating flexibility. This type of train with its inherent advantages and disadvantages is certainly different to what Talgo has been building, but striving as always to provide operators with efficient, reliable and economical solutions we recently unveiled Talgo XXI, a new generation of articulated trainsets with a power car at each end.

Available with the option of Talgo RD automatic gauge-changing, each power car has one bogie with both axles powered (B) and shares a Talgo Pendular wheelset with the first coach. The power car for the Talgo XXI is therefore known as the BT, and the first diesel-hydraulic unit was developed in conjunction with Krauss-Maffei which also undertook assembly. This unit is powered by a new 12-cylinder V-formation MTU engine developing 1500 kW at 1800rev/min, driving a Voith hydraulic transmission. A six-cylinder MTU engine provides auxiliary power for the train.

Talgo and Krauss-Maffei will undertake future diesel BT production, and Adtranz is currently developing traction equipment for the electric version which will have a higher continuous rating. Within the next few months we therefore expect to offer customers single and multi-voltage BT power cars, as well as the diesel-hydraulic version.

All BT power cars will have an axleload no greater than 18 tonnes, with body-mounted braking cylinders acting on five disc brakes assembled on a single axle. In addition, the diesel power cars will have hydrodynamic braking and the electric version rheostatic and regenerative braking. With two power cars, the diesel Talgo XXI will have 10 intermediate coaches and the electric version 12 coaches. Both versions will be capable of 220 km/h operation.

Series 7 coaches

Like the BT power cars, the Series 7 coaches of the Talgo XXI have been designed for operation at speeds of up to 220 km/h, with lateral acceleration measured on the plane of the track no greater than 1·6m/s2. Trials carried out to date on various types of track have met our highest expectations.

The coaches are connected to each other and to the power cars using the articulated Talgo system, incorporating proprietary anti-overturning and anti-overriding technology. As well as the aesthetic benefits, the smooth profile of the inter-car connections reduces air resistance and therefore the amount of energy required to move the train.

Mounted on individual stub axles, the wheels are steered by a simple, robust and maintenance-free mechanical system which keeps them parallel to the rail at all times, both on curves and on straight track. This has obvious safety benefits, as well as the economic advantages of reducing rail and wheel wear. The Talgo system of individual wheels also eliminates hunting, which is both uncomfortable and dangerous at high speed, and simplifies maintenance as wheels which do not share a common axle are not required to have exactly the same diameter or profile.

The suspension is similar to that on the Talgo Pendular, with passive tilt on curves that does not require a detection system or powered actuation. Providing high levels of safety, comfort and reliability, our tilting system has been installed in over 850 vehicles currently in service in Europe and the USA, which over the last 20 years have carried more than 42million passengers.

The 13·1m long bodies of the Series 7 coaches are constructed from welded aluminium alloy extrusions. Aluminium construction and the smaller number of axles per metre of train length mean that the Talgo XXI has probably the lowest weight per seat of any modern inter-city train. Compared with earlier builds, the interior layout of the coaches has been slightly changed, with air-conditioning equipment mounted under the frame. This has allowed the passenger saloon to be widened, with a 2+2 arrangement of up to 40 seats in Tourist class.

The interiors are noteworthy for their spacious and comfortable ambience, created in part by the five large windows on each side of the coach. The reclining seats have footrests and can be turned to face the direction of travel. Each one is equipped with a folding table, a power point for a laptop computer, a reading light and volume and channel controls for the passenger entertainment system. There are four audio and two video channels, with programmes broadcast on ceiling-mounted monitors.

These screens will also display on a route map the location of the train, as determined in real time by GPS. LCD screens in the coach vestibules will enable passengers to access an interactive train information service. Auxiliary equipment on the Talgo XXI is monitored by a diagnostic system, which in real time sends reports on equipment condition to the maintenance depot, warning of any faults or breakdowns.

Talgo XXI coaches seat 26 or 29 passengers in Preferente (first) class and 36 or 40 in tourist, with fewer seats where disabled accommodation is provided. A range of options exists for the layout and equipment of the bistro/cafeteria car, which has high-level windows to allow standing customers to enjoy the view. A service door is provided for the loading of catering supplies and equipment.

High speed market

In March 1998 Talgo signed an agreement with Adtranz for the development of a high speed power car, which with the Series 7 coaches will form the basis of our high speed product. The coaches will be pressure sealed, and will be mounted on specialised wheelsets with primary suspension for operation at speeds up to 350 km/h. This train will be Talgo’s offering for Spain’s next high speed line between Madrid and Barcelona, and we expect to unveil the prototype in March 2000.

CAPTION: The 220 km/h prototype Talgo XXI trainset with integral diesel power cars is currently on test with Spanish National Railways

CAPTION: The bistro/cafeteria car (right) has high-level windows which allow standing customers to enjoy the view

CAPTION: The Series 7 coaches used in the Talgo XXI have a wide bodyshell allowing spacious 2+2 seating in Tourist class (right), and more comfort in the Preferente class 2+1 cars (left)