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.