Abstract: The invention relates to the lining of an excavation with pile planking elements (7,8) placed one above the other, which are displaceable in vertical guide means (5) with the use of barrel-like rollers movable in guiding profiles. The lower pile planking element (8) may be removed after displacement behind the upper pile planking element. For this purpose the vertical guide elements attached to the vertical guide means are arranged in such a way that they are backwards displaceable, for example by means of hingeable levers (24,25). The planking element consists of two parallel flat plates (30,31), which are connected by terminal profiles (32,33) between which spacer elements (40) are present in the form of hat-like prolonged parts.