Rehandling of bulk deliveries of concrete can proceed by direct unloading into unit containers, if these are of large enough capacity, or via the intermediate agency of storage hoppers. Central storage hoppers ensure a uniform and uninterrupted supply to the handling equipment when relatively small quantities of concrete have to be distributed at a site. All hoppers should provide a vertical drop at the discharge gate. If discharge is at an angle, the coarse aggregate will fall to the far side of the container being loaded, and the fine material to the near side, causing segregation. Center discharge is preferable for the same reason. Chutes provide one of the simplest and most economical ways of handling large quantities of concrete; they can also be one of the least satisfactory. Special precautions are necessary to ensure that discharge is vertical at the chute end to prevent segregation. A baffle should direct the concrete into a vertical donpipe at least 2 feet down. In general, an open chute should be as short as possible; longer chutes should be covered to reduce drying and slump loss. Drop chutes of the elephant trunk type should be used where falls into formwork are greater than can be tolerated with open chutes and downpipes. Drop chutes are fitted with collection hoppers or elephant heads, of which there are three basic designs: one side open for use with buggies; four sided funnels for charging with normal slump concrete and extra steep sided hoopers with a rectangular top and a large oval discharge opening feeding the chute. Placing concrete by drop chute is normally restricted to distances of less than 25 due to the danger of segregation. Wheelbarrows are used today mainly to transport very small quantities of concrete. For loads of 6 to 8 cubic feet, hand buggies can be used. Larger loads require the use of a power buggy. Distributing concrete around a site by simple hand guided booms or gantries has been experimented with on a number of occasions. The method is most suitable for use with a site mixer where small quantities have to be handled over a dispersed area. In recent years, the adoption of ready mixed concrete, with rapid buggy distribution, and the greater availability of cranes, has largely made boom handling uneconomic.