This will largely depend on the production facility, the type of beams, and the working procedures used. Some factories, especially those producing flooring units, are highly automated and the placing of strands is mechanised, pulling multiple strands (or wires) along a casting bed. In other cases, strands may be individually placed by hand.

In all cases, it is important that the operation is only carried out by trained operatives. Prior to applying stress, the anchorages have to be inspected for correct operation. Tensioning is a potentially dangerous operation, and it is vital that strict safety measures are adhered to. Sometimes multiple strands are tensioned simultaneously with a single jack, and sometimes each strand is individually tensioned. It is vital that both ends of the strand are correctly located to avoid any twisting. Measures must be taken that if a strand breaks it cannot cause injury or damage. In some types of unit such as double tee beams or bridge beams, strands may be deflected rather than straight, to control concrete stresses, and this needs even more specialised skills.

A few factories host visits to see their operations, often organised by professional bodies. If you live near a factory it may be worth enquiring about such a visit.

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