Bogie type Y25

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Newly delivered Y 25 bogie in 2009
Y 25 bogie in cast design
Y 25 bogie in welded design

The type Y 25 bogie is the most frequently used bogie for freight cars in Europe . It was developed by the French state railway SNCF in the mid-1960s and is still produced in various designs today.

history

Development and dissemination

In the 1950s, the Minden-Dorstfeld bogie from Germany (known as the "Y19" in France) was very popular. It had leaf springs that were attached to the bogie frame with spring hooks , and steering axles that caused little wear when going through radii. The disadvantage of the Minden-Dorstfeld bogies, however, was their pronounced sinusoidal run on straight track sections. Since the French rail network had fewer curves and smaller curve radii than the German rail network, the French state railway SNCF decided to develop its own bogie, the properties of which should be optimized for straight travel. In 1960 the bogie types Y 21 and Y 23 were introduced. The distance between the axles on these bogies was 2,000 mm. In the mid-1960s, the Y 25 bogie with a wheelset base of 1,800 mm was finally introduced. As a result, different variants emerged, which were designated with their own generic letters. The variant Y 25 Cs - the C stands for the maximum axle load of 20 t, the s for the maximum permitted speed of 100 km / h - was certified as a standard bogie by the UIC Railway Association in 1967 .

The Y 25 bogie then spread to other countries. The Deutsche Bundesbahn began using freight cars with Y 25 bogies in 1978. At that time, many manufacturers were making Y 25 bogies, including the Talbot wagon factory in Aachen . In the 1990s, the Y 25 bogies completely replaced the most important designs based on leaf springs.

Today's use

Type Eaos open freight car with Y 25 bogies in Hungary
Type Sgns 481 container wagon of the Deutsche Bahn with Y 25 bogies

Despite the advanced age of the construction, the Y 25 bogie is the most widely used freight wagon bogie today and is constantly being rebuilt by various manufacturers. The Y 25 bogie is comparatively easy and inexpensive to manufacture, and the rights to the construction have already expired, which enables Eastern European wagon factories in particular to maintain the price level that is crucial for freight transport. Be of a bogie manufacturer for the Y 25 family characteristic, in the standard DIN EN 16235 specified properties and tolerances met, must perform this no track driving tests for the approval process, which lowers its cost again. The standardization of the most important components resulting from standardization and the widespread use make it possible on the one hand to use it in almost all European countries within the framework of interoperability in rail transport , on the other hand, the technical know-how is available in the maintenance workshops throughout Europe, a defective Y 25 bogie to repair professionally. The disadvantages of the Y 25 construction, which include suboptimal running properties, poor stability and a maximum axle load of originally 20 t, later 25.5 t or 23.5 t, are known and have motivated various manufacturers to move on in recent years Based on the requirement profile for Y 25 bogies to bring your own bogie designs onto the market. However, so far, particularly in the case of ordinary freight wagons that have no specialized purpose (e.g. bulk goods wagons), no bogie that differs significantly from type Y 25 has been able to establish itself.

The desire to be able to use the bogies of the Y-25 family for vehicles with wheel loads of 25 t led to the new development of the wheelset bearing housing. With these reinforced wheelset bearing housings together with improved wheel bearings, one of the disadvantages of the Y-25 bogies could be eliminated. And since they are downward compatible, these new 25 t wheelsets can be installed in the existing, old Y-25 bogies without modification.

technology

Specifications

The Y 25 bogie was built in many variants, but there are still some characteristic features: the center distance is 1,800 mm, the wheel diameter 920 mm. The bogie frame is 3,250 mm long and 2,200 mm wide. The maximum permissible axle load is usually 20 t, depending on the design up to 23.5 t. An average Y 25 bogie has a mass of around 4.5 t.

Bogie frame

The main components of the Y 25 bogie are two side longitudinal members that accommodate the wheel sets and a main cross member with pivot pins located in the middle between the wheel set shafts. The first Y 25 bogie frames consisted exclusively of these elements and are now known as the Y 27 type. Head cross members were added later to enable two additional brake blocks to be attached to each wheel set. Another central solebar was also added. The longitudinal girders of the bogie are torsion-resistant, the main crossbeam, however, torsion-soft, to handle loads that z. B. due to track position errors are not the same size on both sides to be able to record. Y 25 bogies are available in cast or welded versions with the same dimensions . In the case of welded Y 25 bogies, the girders are welded together from several parts, whereas in the cast variant, mainly three cast parts - two solebars and a main crossbeam - are used. In the early years, many cast Y 25s were made, as suitable foundries in France could deliver large numbers. Today the welded version is mostly chosen because it is both cheaper and lighter.

suspension

Axle set bearing on a Y 25 bogie with coil springs and Lenoir damper (left)

The suspension of the Y 25 bogies is usually provided by a total of 16 coil springs . Two coil springs are always nested in one another. The inner spring lies within the outer spring, which has a larger diameter. In operation, the outer spring first becomes effective. Only when the outer spring exceeds a certain spring travel does the inner spring become active. This is usually the case when the car is fully loaded: For this reason, the inner spring is also called the load spring, and the outer tare spring. There are four such pairs of springs on each wheel set - two on each side. The flexicoil effect of the coil springs enables the wheel sets to be adjusted radially in the curved track.

The winding direction is specified by the UIC . On wheelsets with an axle load of 20 tonnes, the tare spring is wound on the right, the load spring is wound on the left. On wheelsets with a 22.5 tonne axle load, the tare spring is wound on the left, the load spring is wound on the right. Since the UIC regulations also stipulate that all tare springs must have the same direction of winding, and that all coil spring pairs (i.e. the tare and load spring) have a mutual direction of winding, it is easy to see whether the correct springs have been installed even without a visible address / label .

Unlike leaf springs , coil springs do not have their own damping. Lenoir dampers are used on the Y 25 bogie to avoid resonance. A patent for this cushioning was applied for in Paris in March 1960 by Albert Lenoir and the French state railway SNCF. The Lenoir damper consists of a spring lock , one end of which is attached to the bogie frame and the other end to a friction piece on the spring. In this way, both longitudinal and transverse movements are dampened and load-dependent damping is achieved. The spring shake is always located on the inner pair of springs of a wheel set.

Some bogies were given rubber scroll springs instead of coil springs.

Related types

The following list shows the related types and their deviations from type Y25.

  • Type Y21; 2 m wheelbase
  • Type Y23; 2 m wheelbase, without end cross member and brake system on one side
  • Type Y25 Lsod; Radially adjustable axles by arranging Lenoir dampers on both wheelsets
  • Type Y27; without head cross member, one-sided braking system
  • Type Y27 D1; like Y27, but the running circle diameter of the wheels is 840 mm
  • Type Y27 Or LDsm; 1.8 m wheelbase, without end cross member, disc brake with 6 brake discs, axles adjustable in radial direction by arranging Lenoir dampers on both wheelsets, only used by SBB.
  • Type Y27 Or LDssm; like Y27 Or LDssm, but disc brake only has 4 brake discs, only used by SBB.
  • Type Y 27 Or LDssmf; like Y27 Or LDssm, but also with one-sided block brake as a parking brake and weighing valve, only used by SBB. This bogie is used under the ATCS wagons Slps-xy with the numbers 82 85 7 472 300 ... 311 together with a bogie of type Y27 Or LDssm.
  • Type Y31; Without head cross member, brake system on one side, wheels with 840 mm running circle diameter
  • Type Y31 C1; like Y31 but running circle diameter of the wheels 760 mm. The bogies are identical to the DB type 707 with a 730 mm running circle diameter and the DB type 631 with a 680 mm running circle diameter, but they use both type 77 wheelsets
  • Type Y33; 2 m wheelbase, without end cross member, brake system on one side, running circle diameter 840 mm. The bogies of the DB type 632.0 and 633.0, as used in the Sylt Shuttle wagons, are similar, but have wheels with a running circle diameter of 680 mm.
  • Type Y35; 2.2 m wheelbase, cradle with pendulum suspension, without cross member, one-sided braking system. This design is approved for a 16 t axle load for 140 km / h. This design is mainly used for motor coaches in France.
  • Type Y37: 2.3 m wheelbase, cradle with pendulum suspension, no head cross member, disc brakes and one-sided additional block brake, smaller wheels with a running circle diameter of 920/840 mm. This design is approved for 160 km / h with an 18 t axle load.
  • Type Y39: 2.2 m wheelbase, running circle diameter 680 mm

Web links

Commons : Y 25 Bogie  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b c d e f Hermann Jahn: Güterwagen-bogies: Y 25 on Drehgestelle.de , accessed on October 15, 2015.
  2. ↑ a b c d e f g h i j Karl Gerhard Baur: Bogies - Bogies. EK-Verlag , 2nd edition, Freiburg 2009, ISBN 978-3-88255-147-1 , pp. 164-167.
  3. ↑ a b c Detlef Scholdan: New freight car bogies - an inventory. ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Website of the Institute for Rail Vehicles at RWTH Aachen University , accessed on October 15, 2015. @1@ 2Template: Webachiv / IABot / www.ifs.rwth-aachen.de
  4. ↑ FAG axle box bearings for freight car bogies type Y25 / 25t (PDF)
  5. ↑ AVV Annex 10 Annex 2
  6. ↑ AVV Annex 10 Paragraph 4.22
  7. ↑ AVV Annex 10 Paragraph 4.23
  8. ↑ Y25 with radially adjustable wheel sets. In: www.drehgestelle.de. Retrieved October 27, 2015 .
  9. ↑ a b c Y25 with radially adjustable wheel sets. In: www.drehgestelle.de. Retrieved October 27, 2015 .
  10. ↑ Y 25 - Main page. 3. 4 main types, features. In: www.drehgestelle.de. Retrieved October 27, 2015 .