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Elastic Ribbed Base Plate Support ERL

Elastic Ribbed Base Plate Support ERL for compensation of static and dynamic forces

Elastic Ribbed Base Plate Support ERL

The weight of vehicles causes static forces to act on rails and the trackway. The rolling wheels, through discontinuities in wheel and rail, generate additional forces and severe vibrations. With speed acceleration, these forces are magnified, thus leading to rapid wear of the entire trackway and a corresponding displacement of the track. Furthermore, the turnout is influenced by the steady change of contact points between wheel and rail, when set of switches and frog are overrun. A permanent and proven remedy is achieved through the use of Elastic Ribbed Base Plate Support ERL, a voestalpine Turnout Technology Germany development.


Design and Function

Spring rigidity can be adjusted according to the individual customer requirements and applications – the deflection always indicated by a kinked spring characteristic. This means that in case of rail breakage, the deflection is limited to a pre-defined extent.
Given the elasticity of the rail support, the incurred forces are compensated by several support points in the form of a bending curve of the rail. The load on each individual support point and the elastic support is thus accordingly reduced.



For systems of average track rigidity (85 kN/mm), the turnouts in the area of the set of switches as well as in the frog area are equipped with the ERL 30 system plates. The support points in the intermediate rail area are equipped with elastic rail pads, just as in the track.
For systems of low track rigidity (65 kN/mm), the turnouts are provided with ERL 17.5 system plates. For this type of turnouts, which are laid in ballast, additional transition areas in front of and behind the turnout have to be equipped with staggered spring rigidities, depending on speed. This is to compensate for the difference in track rigidity between the turnout and the adjacent rail track.
For systems in slab track, the turnout is also generally provided with system ERL 17.5 plates. However, here the elastic transitions in front and behind the turnout are omitted.
For easy adjustment of track and level discontinuities, all ERL plates in the screwing area feature tapered sleeve inserts permitting a horizontal correction of ERL of +/- 9 mm. Level compensations of -4 mm to +26 mm, respectively, are possible at any time using leveling shims. For any vertical corrections exceeding this level, the screws need to be replaced.



  • Forces are decomposed where they arise
  • Rapid and easy correction of horizontal and vertical positional displacements
  • Substantial minimization of permanent track way maintenance
  • Individually adjustable spring rigidity
  • Kinked spring characteristics ensuring high safety
  • Little maintenance effort
  • High availability
  • Fast payback