Production process

Each sleeper has an average weight of around 330 kilos and ANTRASA’s sleeper production process is a closed cycle with the following stages:

• Visual inspections of the moulds to be used in manufacturing.
• Preparation of the mould with the application of the release agent, positioning of the sheaths, reinforcement, active reinforcement structure (steel rods) and tensioning.
• Filling of the moulds with concrete with a special dosage and vibration of the moulds on a vibrating table.
• Thermal curing of the pieces of concrete in curing ovens which reach a suitable temperature and level of humidity to ensure that they set through a controlled and automatic cycle, as established by the ET Standard.
• De-tensioning of the moulds and transference of the tension to the active reinforcements (the tension passes from the steel rods to the concrete).
• Overturning of the moulds for the pieces to be demoulded.
• Positioning of the track-fastening components (lag bolts, support plates and clips) and visual surface inspection.
• Palleting of sleepers in batches of 20 and shipping of the batches to be stored so that they can be matured and shipped.
• Storage in the main stockpile.
• Shipping by rail or lorry using a gantry crane.