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Elastic Ribbed Baseplates
Cross section of the arrangement of the elastic elements
Discontinuities of the rolling wheel and the track cause static loads from the vehicle mass to be superimposed by considerable dynamic loads, which affects the permanent way.
With increasing speeds the dynamic loads as well as the amplitudes of transverse vibrations increase with the dynamic forces superseding the static forces by far in the upper speed range.
The vibrations and forces cause wear of the parts of the superstructure, in the worst case the ballast is destroyed and subsidence in the substructure occurs.
The consequences are changes of the position of the track which lead to higher wear and more subsidence within the turnout when the switch device and the crossings are overrun.
A lasting and proven remedy is the elastic bedding of ribbed plates ERL, a development of BWG.
Use of ERL
Elastic beddings of ribbed plates are used in high-speed lines, with concrete slab and for acoustic reasons on bridges as well as for layouts with medium elasticity on ballast and for medium speeds.
Elastic bedding of ribbed baseplates for reduction of static and dynamic forces
Features
For highly elastic layouts with a spring stiffness of the track of 65 kN/mm all turnouts are equipped with ERL 17.5 plates.
Adjustments of the gauge and height due to wear are easier to do because all ERL plates have conical bushes in the bolting area which allow horizontal adjustment of the ERL by +/- 9 mm. Height adjustment of -4 mm and +26 mm is possible by inserting plates. Higher vertical adjustments are also possible,
however require the bolts to be exchanged.
For turnouts in ballasted track transition areas in front of and after the turnouts are designed with graduated spring stiffness depending on the speed in order to compensate the higher spring stiffness of the track relative to lower track stiffness within the turnout with elastic bedding.
For layouts of medium elasticity and a spring stiffness of the track of 85 kN/mm the turnouts are equipped with plates ERL 30 in the area of the switch device and the crossing. The supporting points in the area of the intermediate rail are equipped with elastic pads, e.g. ZW 900.
For easy adjustment of faulty gauges and height due to wear all ERL 30 plates have oval bushes in the bolting area which allow horizontal adjustment of the ERL by +/- 8mm.
Height adjustment is not the standard, but can be supplied on request.
For turnouts in ballasted track transition areas in front of and after the turnouts are designed with graduated spring stiffness depending on the speed in order to compensate the higher spring stiffness of the track relative to lower track stiffness within the turnout with elastic bedding.
For layouts of medium elasticity and a spring stiffness of the track of 85 kN/mm the turnouts are equipped with plates ERL 30 in the area of the switch device and the crossing. The supporting points in the area of the intermediate rail are equipped with elastic pads, e.g. ZW 900.
For easy adjustment of faulty gauges and height due to wear all ERL 30 plates have oval bushes in the bolting area which allow horizontal adjustment of the ERL by +/- 8mm.
Height adjustment is not the standard, but can be supplied on request.
Advantages
- Reduces load of supporting points and bedding
- Quick and easy adjustment of horizontal and vertical deviations of position
- Considerable reduction of permanent way maintenance
- Spring stiffness made to measure
- High safety due to kinked spring characteristic
- Quick amortization
- High availability
- Low maintenance
Technical characteristics:
| Track speed | < 160 km/h < 200 km/h > 200 km/h |
| Mean track stiffness [kN/mm] | 135 kN/mm (+/-10%) 85 kN/mm (+/-10%) 62 kN/mm (+/-10%) |
| Recommended ERL stiffness [kN/mm] ] | Rigid bearing ERL 30 with approx. 30 kN/mm ERL 17.5 with approx. 17.5 kN/mm |
| Nominal subsidence with ERL 17.5 | ~ 2 mm |
| Maximum subsidence | ~ 4 mm |
