Abstract: The invention concerns an impact compactor comprising a noncircular roller, draft arms positioned on both sides of the roller, axle means supported about the draft arms and on which the roller is mounted for rotation, a draw bar pivotally connected to the draft arms for towing the roller, and a gear and pinion linkage between the roller and the draft arms. Outer gears may be fast with each side of the roller. Each draft arm may support a stub shaft on which a pinion is mounted to mesh with the outer gear and to co-operate with a ratchet mounted on the draft arm. A buffering device can be provided between the draft arms and the draw bar.

Abstract: A displaceable load supporting cell for supporting a load. The cell comprises at least one compacted layer of particulate material compacted under a pressure of at least 800 kPa. The cell has a height less than its minimum lateral dimension. The cell includes retaining means for retaining the particulate material in the layer, and restraining means associated with the layer to restrain lateral displacement of the particulate material under load.A method of forming the load supporting cell and a support pillar. The pillar comprises a stack of layers of particulate material compacted under a pressure of at least 800 kPa, and each layer having restraining means associated therewith to restrain lateral displacement of the particulate material under load, each layer having a height less than its minimum lateral dimension.