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Repair of a catenary supports suffering from 80% of corrosion with composite wrapping

News International-French

19 Feb 2016

The hybrid concept, patented by the SNCF (French National Railway Company) and 3X Engineering, consists in reinforcing corroded catenary supports with metal inserts and composite wrapping.

The R4D HEA is a hybrid concept which repairs and strenghens your catenary supports. Made of very high-performance materials, it is designed for lasting 20 years minimum, while supporting the constraints undergone by the catenary support: weight, vibrations, wind, bad weather and ballast impacts.

The objective of the repair performed in May 2015 by 3X Engineering was to reinforce 15 corroded catenary supports of 50 years old situated on a railway line in the South of France.

Corrosion drive to a loss of thickness that modifies the mechanical integrity of the catenary support. The R4D HEA is made of advanced materials used in the aeronautical industry: epoxy resin and Kevlar. Metal inserts are integrated on the original HEA base to give back the original mechanical resistance. The advantage of this hybrid conception is the rigity with the metal inserts and the flexibility with the composites.

The R4D HEA is developed to repair a support which has lost 70 to 80% of its initial thickness. It has been designed using CAD modeling and 3X Engineering experience.

The repair has been designed using modelisation and finite element simulation to define the size of the repair.

First of all, the bases of the structures have been properly prepared to receive ReinforceKit Beam product (vegetation cleaning around the support, water removal and support drying …)

The beam reinforcements have been performed following several steps : 

1/ Surface preparation with sandblasting to get a good surface roughness (60-micron surface profile).

2/ 3X filler application at the base of the structure for sealing the junction between concrete and beam and for stopping corrosion.

3/ Metal inserts preparation and application.

4/ Composite reinforcement wrapping using Kevlar and 3X specific resin around the base of the structure.

5/ Special coating application to protect the repair against UV & impacts and reference plate installation for traceability.

Based on its experience acquired since 2011 in the transport industry, 3X Engineering has been able to restore the integrity of all the damaged beams without stopping train traffic. This accurate implementation needs to be performed with high-qualified applicators and top quality products. Since the launch of this product over a thousand of supports have been renovated.

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