The accompanying drawing, see Figure, shows a cross section through the grab when closed, with dotted lines indicating the path of its jaws from an open to a closed
position. To the housing of the grab is fastened (to obtain the compound movement) a rail or track T, upon which are hung sliding blocks or pieces bb, pivotally connected with the forward portion of the jaws JJ, which are composed of two parallel sides pp, joined at their outer ends by cutting blades DD which are set at a sharp outward angle. The parallel sides pp, however, are cut away and recede upwardly from the lower or scraping edges toward their upper ends, so that when the jaws J J are brought together and the grab thereby closed, a small portion of the sides will remain open.