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Amgueddfa Cymru
Steel quick-release chock. Painted blue. Used on coal face as "breaking chock". This is unusual and maybe a one off as timber was usually used for this purpose. These items were used during the 1960s and early 1970s. They were used all along the face line as a moveable roof support and preceeded the hydraulic roof support systems of the 1970s - present day.
They were usually painted white and the blue finish is probably the (unknown) manufacturer's colour
