The 598 series trains specialise in mid-distance services and are based on the 594 railcars, although they have higher capacity and better features. They were built by CAF at its factory in Beasain and came into service in 2004. The exterior boasts an aerodynamic front end and large running window throughout the train, and have an in-built SIBI Tilt System.
The set of carriages has 189 seats plus one for people with reduced mobility. It has two driver's cabs, one in each engine car.
A toilet adapted for people with reduced mobility and baby changer can be found on the platform of one engine car, while on the platform of the other engine car is a conventional toilet.
All three carriages have two rooms. A large passenger lounge, where two seats are available for passengers on either side of a central corridor. The centre seats are equipped with a fixed table and the remainder with a folding tray.
Overhead roof racks are available, in addition to a large luggage rack next to the door.
Identical to the large lounge, the small lounge in all carriages has two seats on either side of a central aisle. There are seats with fixed tables and others with folding trays. A bike rack for up to six bikes has been installed in one of the engine cars.
The seats in both lounges are reclining and feature folding armrests. The windows are equipped with manual, height-adjustable curtains.
This train is also equipped with air conditioning systems, internal and external passenger information, public address system and ambient music, fire detection, etc.
598-series trains, consisting of 21 units received between the first quarters of 2004 and 2005, were manufactured by CAF at their Beasain factory and came into service in Galicia in December 2004. Conceptually, they are based on the 594 series, although significant improvements and innovations have been introduced.
Its external design is worth particular mention, with curved lines, including an aerodynamic front end, similar to that of high-speed trains, and a large running window throughout the entire train.
This train consists of three carriages, two engines located at the ends and an middle trailer. It has 32 percent greater capacity and higher performance than the 594 series. Since its construction, it has incorporated the SIBI Tilt system that, through GPS positioning, recognises the layout of the track, tilting the train depending on its speed and radius of the curves. All its equipment is duplicated and optimised so that a failure in any one system does not result in service downtime.
It is an exclusive train for a track gauge of 1,668 mm and can reach a top speed of 160 km/h.
The structure of the 598 unit is constructed from lightweight aluminium alloy and consists of two engine cars and one trailer car (M-R-M), with a smooth case on the sides and a window running along the entire set of carriages. This provides a sense of continuity that is enhanced with rubber deflectors between the vehicles to hide the intercommunicating bellows. The minimum setup is three carriages and the maximum is three units (nine carriages); it is coupled using automatic Schafenberg couplings. These couplings are hidden in the faired front ends of the engine cars by means of an opening and closing device consisting of a double articulated, sliding bar mechanism.
The most characteristic feature of these trains is their peak-shaped front-end, similar to the design of high-speed trains, which improves their aerodynamics, increases their air penetration coefficient and decreases drive effort. The front end houses display monitors and LED headlights.
Its increased height is also worth mention, as the body fairing covers the equipment located under the frame and the air conditioning and cooling equipment at the top. The structure of the body is self-supporting and consists of large aluminium extruded profiles.
The energy absorption system utilises oil shock absorbers in the couplings, carriage anti-tilt system with rigid stops and honeycomb structures, both in terms of the structure of the bodies and the passenger lounges, which absorb deformations and minimise the consequences of a head-on collision.
The front end of the engine cars houses a top headlight and two lower headlights for outdoor signalling. The upper headlight has two lights and both have low and full beam functions. The lower headlights employ high performance LEDs. Each features white LEDs, which are used to perform headlight functions, and red LEDs, when they function as a tail lamp position indicator signal. Furthermore, it has destination indicators at the front end and carriage number on the sides.
The traction system consists of four D 2879 LUE 605 diesel engines, two in each engine car, with a unit power of 338 kW and a total of 1,352 kW. These four-stroke engines with four valves per cylinder, were manufactured by Man, with a cylinder capacity of 12,820 cubic centimetres, direct injection of fuel, controlled by an electronic system depending on multiple variables and the demand requested by the machinist.
The transmission of engine power to the bogie motor axle performed using the oleodynamic turbo-transmission coupled to the axle reducer by means of a Cardan-type joint. The engine cooler, using water, is located on the roof.
This aspect sets them apart from the rest of the diesel fleet, on which the engine cooling equipment is located under the frame.
Auxiliary services are independent from traction services, as they are powered by two 230 kw engines located in the middle carriage. Each engine powers a 210 kVA alternator, which provides an output voltage of 380/220 Vdc and 50 Hz to power the different auxiliary equipment.
The auxiliary equipment's electrical system has the redundancy of two generator sets formed by a diesel engine plus an alternator. It works with a single group and they replace one another relative to the number of hours of activity.
It has three 24 Vdc (nickel-cadmium) batteries, located under the frame of each carriage's body. The battery of each engine car starts the two diesel engines corresponding to the same carriage and the trailer car battery starts the battery of the alternator to be used. The batteries are also used to power emergency lighting and cleaning tasks.
It is equipped with two air production devices located under the frame of the trailer carriage body. It consists of two compressors, although during the normal operation of the vehicle, only one is in service.
It has a fuel tank with capacity for 1,400 litres of diesel, allowing the train to travel approximately 1,000 kilometres before needing to refuel.
The body of each carriages features two bogies, meaning each set of carriages has four motor bogies and two trailer bogies. Each engine car bogie has a mounted engine axle and a mounted carrier axle. The trailer car bogie has two carrier axles. All axles feature two solid wheels measuring 850 mm in diameter and two brake discs measuring 610 mm in diameter. Each bogie weighs around 9,000 kilograms.
It is equipped with primary suspension and secondary suspension. The primary suspension elastically joins the grease trays with the bogie frame, allowing it to transmit both vertical loads (via two packages of two vertical coaxial springs) and transverse steering and drag efforts between the end of the mounted axle and the rest of the bogie. The secondary suspension is pneumatic in nature, on account of the presence of two pneumatic springs (balls) located on either side of the bogie, between the load bolster and the swinging bolster.
Each bogie is equipped with two sand ejectors, a secondary pneumatic suspension installation, a pneumatic brake installation, electrical connections for anti-lock sensors, a Asfa catcher and grounding. Between the primary and secondary suspension are the tilt system activation mechanisms. Each bogie also features two active yaw damper that only operate at speeds upwards of 130 km/h.
The unit's braking system consists of a service brake that uses the hydrodynamic brake; the pneumatic, compressed air and automatic brake; or a combination of the two. The braking distance at 160 km/h, is about 1,100 metres. There is also an emergency brake that replaces, in case of failure, the electro-pneumatic control system, and a parking brake, in the form of a spring brake, to ensure the immobility of the train.
The brake is always engaged using the hydrodynamic brake capacity. When this brake is not enough, it is complemented by the pneumatic brake. The train also has anti-lock and anti-slip systems on all axles.
These railcars are equipped with the SIBI Tilt system, a system that uses what is known as an active tilt function. This type of predictive movement consists of prior knowledge of the route, recorded on the train's computer equipment, and in the communication of its position via GPS. Given its knowledge of these circumstances, the train actively tilts, at all times, in line with its speed and the radius of the curve, even before starting the curve. At any time, the driver can enable or disable the system, using a pushbutton located on the control desk.
SIBI responds at the right time, substantially increasing passenger comfort and tilting the train body to the right degree, depending on the geometry of the track and the travel conditions, applying dynamic laws of comfort.
SIBI allows 598-series railcars to drive at the D-speed type, increasing the speed at which they can take corners, a maximum speed that is communicated to the driver via a display located on the control desk. As is the case of tilting TDRs, if SIBI stops working, the train passes to speed B and, if the tilt is not operational, to type A.