The weight of vehicles causes static forces acting on rails and trackway. The rolling wheels, by discontinuities in wheel and rail, generate additional forces and severe vibrations. By acceleration of speed, these forces are raised to a higher power that leads to rapid wear of the entire trackway. The result is a corresponding displacement of the track.

Inside the turnout, further influences result from the steady change of contact points between wheel and rail, when switch and crossing are overrun. Permanent and proven remedy is achieved by the elastic support of ribbed plates ERL, a development by BWG.

Design and Function
We can adjust the spring rigidity according to the individual customer requirements and applications, the subsidence always being indicated by a kinked spring characteristic. This means that the subsidence is limited to a defined extent in case of rail breakage.

By the elasticity of the rail support, the forces incurred are compensated over several support points in form of a bending curve of the rail. The load on each individual support point and of the elastic support is reduced accordingly.

Application
For systems of average track rigidity (85 kN/mm), the turnouts in the area of the switch and in the crossing section are equipped with plates of the system ERL 30. The support points in the intermediate rail area are equipped with elastic rail pads as in the track.

For systems of low track rigidity (65 kN/mm), the turnouts as such are provided with plates of the ERL 17.5 system. For this type of turnouts, which are laid in ballast, additional transition areas in front of and behind the turnout must be equipped with staggered spring rigidities, depending on speed. This is to compensate for the difference in track rigidity in the switch and in the adjacent rail track.

For systems in slab track, the turnout is also generally provided with plates of the system ERL 17.5. However, here the elastic transitions in front of and behind the turnout are omitted.

For easy adjustment of track and level discontinuities, all ERL plates in the screwing area show 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 levelling shims. For any vertical corrections exceeding this level,
the screws have to be replaced.

Highlights

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