Nabla RNTS Clip for Rail Fastening Systems

A Nabla RNTS clip (often referred to simply as a Nabla rail clip) is a spring-steel elastic fastening element used within the Nabla RNTS rail fastening system, which secures rails to concrete (or other) sleepers in railway track structures. It is one of the key components that clamps the rail foot to the sleeper baseplate, providing mechanical restraint while also contributing to vibration damping and track stability.

Nabla RNTS is a classic STEDEF-style rail fastening system primarily used for trams, light rail (LRT), and metro tracks. It is specifically designed for installation on flat concrete sleepers (or slabs) and is characterized by its use of a cast-iron base plate to support the rail. 

Key Features and Benefits

• Vibration and Noise Reduction: Optimized to dampen ambient noise and vibration, making it ideal for urban environments.

• Versatile Installation: Can be installed in situ or on pre-cast sleepers, and is compatible with various track beds including concrete, asphalt, natural stone paving, and "green" (grass) tracks.

• High Durability: Engineered to withstand the frequent starting and stopping typical of urban transit systems. 

Key Components

The Nabla RNTS assembly typically consists of the following: 

• Nabla Elastic Clips: Provide the clamping force (toe load) to keep the rail secure.

• Cast-Iron Base Plate: Provides a stable, flat foundation for the rail on the sleeper.

• Elastic Rail Pads: Placed under the rail to provide cushioning and electrical insulation.

• Screw Spikes: Heavy-duty screws that fix the base plate and clips to the concrete sleeper.

• Protective Caps: Covers used to prevent contamination (such as concrete or debris) from affecting the fastening mechanical parts. 

Technical Compatibility

• Rail Types: Supports various grooved and standard rail profiles, including 60Ri1, 60Ri2, 50E2, and Ri54G2.

• Track Types: Suitable for both ballasted and ballastless (slab) track configurations. 

Applications

• The RNTS system is specifically tailored for flat concrete sleepers, distinguishing it from the RNTC variant, which is used for profiled (sloped) concrete sleepers. It is widely used in heavy-duty rail infrastructure and urban transit systems where the STEDEF method is employed to reduce noise and vibration.