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A reliable and highly robust rail fastener for maintenance-free operation.

A simple but highly robust track fastener, the Delkor Alt.1 baseplate was first developed in Germany in the late 1970’s and was derived from the early ‘sandwich’ (non bonded) design baseplates to improve performance reduce maintenance and provide in track durability.

The Delkor Alt.1 baseplate is made up of a SGI top plate and outer base frame that are vulcanised (bonded) together by means of a natural rubber element. The underside of this rubber element is specially profiled and designed to allow movement of the top plate which holds the rail while ensuring a high degree of rail stability. Its most suitable for non-ballasted trackforms where vibration and ground borne noise reduction is required.

A key feature of the Alt.1 baseplate is the outer frame encompasses the top plate, making the unit totally fail safe. The bonded rubber element provides resilience in all six degrees of movement which results in lower vibration and structure borne noise. This feature also dramatically reduces the dynamic stress on the anchoring elements as these elements (screwspikes / threaded rods) only pass through the outer base frame which is totally isolated from the top plate by the rubber element and virtually eliminates in track fatigue failures and maintenance issues over a long period of time.

The profiled rubber element on the bottom side of the Delkor Alt.1 is only exposed to compression loads with its spring characteristic becoming more progressive as the load increases. This avoids excessive deflections in the event of overloading the track fastener. This makes the baseplate ideal for operations where mixed traffic conditions are required.

Another feature of the Alt.1 is that the rubber element is not subjected to any preload (unlike ‘sandwich’ type design baseplates) which ensures resistance to aging and provides excellent dynamic performance and long maintenance-free service life across a wide variety of applications from light rail to heavy haul freight operations.

Delkor Rail’s range of Alt.1 base plates are available in a variety of standard sizes and these designs can be customised and tailored to suit your specific fastening system and operational requirements.


Delkor Egg baseplateDelkor Egg baseplate section view

Design Features

  • Vibration and noise attenuation
  • Low static and dynamic stiffness
  • Dual stiffness capability
  • Bonded one-piece unit: no wearing parts
  • Single rubber dampening element
  • Proven fatigue life
  • Easy installation either by Top Down or Bottom Up construction methods
  • High electrical insulation
  • Fail-safe design
  • Maintenance-free long life performance in excess of 30 years
  • Low profile design available

Technical Data

  • Static Stiffness (Cstat): 16– 35 kN/mm
  • Material: Metal Parts, SG Iron, Elastomer, Natural Rubber
  • Lateral Adjustment: Up to +/- 15mm
  • Vertical Adjustment: Up to 25mm (by packers)
  • Rail Clips: 'e' Type, Skl Type and others
  • Electrical Insulation: > 1 MOhm
  • Vertical Deflection: Up to 3.5mm
  • Ratio Cdyn, Cstat: < 1.4
  • Tested in Accordance to EN (EN13146, EN13481), DIN and other International Standards