Roof beam mould

Self-reacting mould for hollow core roof beams and two-size counter mould for producing beams with and without wings.
An oil-pressured mechanical device inside the buffer mould element contracts it as the product is being extracted and returns the mould to its original state for casting.  
Lengths of up to 110 m can be obtained with hollow core made up of 2 or more re-constructible sections inside the mould; complete with extracting hoist and roller conveyor.