Rail Fastenings Systems

NABLA Evolution

NABLA Evolution is a direct rail fastening system that offers enhanced performance for tracks with tight radius curves. It has been proven in installations for several decades and is recognised for its simple installation and maintenance. By maintaining the track gauge, it significantly increases the life expectancy of assembly components.


NABLA Evolution product overview

NABLA Evolution is suitable for all track types, including heavy haul.

  • It offers improved electrical insulation and lateral force absorption.
  • The unique use of glass-reinforced material in the lateral insulator also offers increased mechanical strength.

Advantages of using NABLA Evolution


Reduces track maintenance

As a result of its deep post insulator, NABLA Evolution offers exceptional resistance to wear caused by lateral loads. This reduces track maintenance overheads.


Simple to install

NABLA Evolution is simple to install, saving time and money.



The use of glass-reinforced material results in a high level of mechanical strength and good lateral force absorption.


Better insulation

NABLA Evolution offers higher electrical insulation than similar systems, making it an efficient, effective option.


Compatible with different types of rail

The system has been adapted for compatibility with all types of rail, including vignole, grooved, AREMA and industrial.



The system offers a good level of lateral adjustment via the insulators, allowing fine gauge tuning and alignment. By maintaining the track gauge on tight radius curves, NABLA Evolution increases the life expectancy of assembly components.

Technical features of NABLA Evolution


High clamping force

An anchor screw is tightened to the contact, ensuring a consistent application of clamping force on the rail and a large range of torque. The high clamping force combined with the design of NABLA Evolution prevents rail roll.


Glass-reinforced material

The glass-reinforced material used in the lateral insulators creates a high level of mechanical strength and good lateral force absorption.


Optimised coach screw

The system’s coach screw offers a large acceptable torque range of between 250 and 400 Nm. Toe load is achieved automatically once the screw is tightened to contact.


Adjustable insulators

A good level of lateral adjustment is provided via the insulators to deal with track gauge and alignment. This allows fine gauge tuning by 1.25mm increment, ±7.5mm per rail seat.


Electrical insulation

NABLA Evolution provides electrical insulation of over 10 K Ohms (EN13146-5:2012). This is higher than standard NABLA systems.


Options for rail pads

NABLA Evolution offers a large range of rail pads, from 35 MN/m for tramways, up to 400 MN/m and above for heavy haul applications and tight curves.

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