FS E.472

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FS E.472
Numbering: E.472.001-017
Number: 17th
Manufacturer: Breda
Year of construction (s): 1923-1930
Retirement: 1945
Axis formula : 1'D1 '
Gauge : 1435 mm ( standard gauge )
Length over buffers: 14,800 mm
Total wheelbase: 11,600 mm
Service mass: 94.4 t
Friction mass: 65 t
Top speed: 75 km / h
Hourly output : 2,000 kW
Driving wheel diameter: 1,360 mm
Power system : 10 kV / 45 Hz three-phase current
Power transmission: Direct power transmission from three-phase catenary to three-phase traction motors via a transformer
Number of traction motors: 2
Drive: Electric motors Gear drive on jackshaft
Rod drive with triangular coupling rod
Brake: Handbrake
air brake

The E.472 series was an electric locomotive series of the Italian state railway Ferrovie dello Stato . It was used on the Italian three-phase test route Rome - Sulmona, especially in passenger train service. When the trial operation ended after 1945, the locomotives were scrapped and none of the locomotives in the series have survived.

prehistory

The operating experience with the Upper Italian three-phase network 3.6 kV / 16.7 Hz during operation at the FS revealed that the selected frequency was on the one hand disadvantageous for operation, on the other hand the selected voltage was set too low with increasing energy requirements . In addition, the direct drive of the traction motors on the axles turned out to be negative for the overloading of the traction motors.

It was therefore decided to build a test track on a trial basis, which was electrified with the 10 kV / 45 Hz three-phase current system. This had the advantage that power plants with the industrial frequency could also be used. It should be a test track with steep gradients and small curve radii. It was therefore decided to electrify the Rome - Sulmona line with 10 kV and industrial frequency.

This required other locomotives, as was previously the case with three-phase locomotives. As with the electric locomotives with single-phase alternating current , the locomotives had a transformer for test operation . In addition, the traction motors worked via a gear transmission on two jackshafts that drove the drive wheels with the usual rod drive. Four locomotives for an express train locomotive ( FS E.470 ), a freight locomotive ( FS E.570 ) and 17 units for the passenger locomotive FS E.472 described here were planned for the test operation. In addition, a locomotive with a converter ( FS E.471 ) was built, which was later converted into the FAV E 440 locomotive of the Ferrovia Alta Valtellina .

History of the Locomotives

The locomotive of the E.472 series is very similar to the FS E.432 , which was built by the same manufacturer, Breda five years later. Outwardly, you can hardly tell the difference between the two locomotives. The E.472 , like the FS E.432, has pantographs , only these have been moved further outward on the locomotive. In addition, it could be distinguished from the FS E.432 by the presence of the oil cooler for the transformer (located in front of the front part) and the jackshafts on the drive triangle. The stems are also less bulky than those of the FS E.432.

The locomotives, like their sister machines, were tested after construction on a section of the Modane – Turin railway line , which at that time could already be fed with industrial frequency. In any case, after 1928 it could only be used on the trial route Rome - Sulmona intended for it. It can only be inferred from the Internet that the E.472.006 had to be withdrawn as early as 1943 after fighting.

Overall, isolated operation with 10 kV / 45 Hz three-phase current did not bring particularly positive results; Although the number of substations was significantly reduced, there were many more difficulties in operating the double catenary, so that the maintenance costs rose significantly. That was the reason why the line was rebuilt with 3 kV direct current after the severe war damage after 1945 .

When the locomotives were scrapped is not clear from the literature. But like their sister machines, they have certainly been deleted from the inventory.

One of the negative results of the test operation was the ancient equipment of the locomotives with rod drives . The electric locomotives with direct current drive had a more favorable control, fewer operational difficulties due to the single-phase overhead contact line and from the beginning single-axle drive . That was the reason why the trial operation on the Rome – Sulmona line was ultimately unsuccessful.

construction

Mechanical part

The E.472 series locomotive was equipped with a 1'D1 'carriage. The outermost of the four driven axles were connected to the barrel axle at the top by a Zara frame . Overall, it can be said that the drive and mechanical equipment was identical to the FS E.432 . The drive motors were set higher in the E.472 and worked via a gear transmission on a jackshaft. This brought a more elastic connection and fewer starting problems for the engines. From the jackshaft onwards, the power was transmitted to the axles via a triangle and the coupling rods, unlike the FS E.432. The reason for this is that the rod drive based on the Bianchi system , for which the FS E.432 actually stood, did not appear until 1927/28. In the numerous photos that can be found on the Internet, the locomotive is only equipped with the triangle.

The locomotives were equipped with pantographs similar to the FS E.432 , but they were placed on an adventurous tubular frame and moved further outwards. Presumably, because of the higher voltage, an increased grinding distance was required. In the numerous photos of the locomotive, it can only be seen with a pantograph on this tubular frame.

Electrical part

In contrast to the FS E.470 series , the E.472 was also equipped with electrical equipment with three speed levels at 37.5 km / h, 50 km / h and 75 km / h. The locomotives developed 1,350 kW at 37.5 km / h, 1,850 kW at 50 km / h and 1,950 kW at 75 km / h. Within the three speed levels, the current taken from the catenary and reduced by the transformer was passed on to the drive motors with the optimal power factor. The speed levels were achieved by connecting the two motors in series or parallel and by using different numbers of poles. At 37.5 km / h, 8 poles were connected in series, at 50 km / h parallel connection and 12 poles, and at 75 km / h parallel connection and 8 poles. The liquid starter , which served as a so-called accelerator between the continuous speeds, was used between the three speed levels . This unit worked as a fluid resistance, which enabled a steady acceleration when starting and when changing to a higher speed level. The mode of operation was similar to that of the three-phase locomotives for 3.6 kV / 16.7 Hz.

The main transformer was oil-cooled. It supplied 1,840 V and 1,600 V undervoltage for series connection or parallel connection of the motors. Two separate auxiliary transformers, each with an oil switch, supplied the on-board network. The oil switch for the main transformer had protective resistors, a changeover switch built in after it enabled the high-voltage winding to be switched from star to delta when operating with the contact wire voltage reduced to 6 kV. The main and auxiliary transformers were housed in a porch. In the other front building was the compressor group, and in front of it the oil cooler for the transformer .

literature

  • Wolfgang Messerschmidt: History of the Italian electric and diesel locomotives Orell Füssli Verlag, Zurich 1969

See also

Web links

Individual evidence

  1. ↑ Internet page about the trial operation of the E.472 on Drehscheibe-online.de
  2. ↑ Short description of the test route Rome – Sulmona on Drehscheibe-online.de
  3. ↑ Wolfgang Messerschmidt: History of the Italian electric and diesel locomotives. Orell Füssli Verlag, Zurich 1969, p. 44.
  4. ↑ Short description of the test route Rome – Sulmona on Drehscheibe-online.de
  5. ↑ Wolfgang Messerschmidt: History of the Italian Electric and Diesel Locomotives Orell Füssli Verlag, Zurich 1969, p. 43.
  6. ↑ Internet page about the E.472 with technical data
  7. ↑ Internet page about the E.472 with technical data